Neuroscience Flashcards
What is the central sulcus?
What’s another name for the central sulcus?
It divides frontal lobe from the parietal lobe
Fissure of Rolando
What’s the precentral gyrus and what is its function?
The precentral gyrus (part of the frontal lobe) is
the primary motor cortex.
What’s the postcentral gyrus and what is its function?
The postcentral gyrus (part of the parietal lobe) is the primary somatosensory cortex with.
What’s the lateral sulcus (aka Sylvian fissure)?
The lateral sulcus (Sylvian fissure) divides frontal lobe from the temporal lobe.
What is the insula?
A structure that is sometimes regarded as the fifth lobe of the cerebrum, is located deep in the Sylvian fissure. Insula is the seat of the primary gustatory cortex.
Where is the dorsolateral prefrontal cortex (in between which sulci and in which gyrus) and what does it do?
In between the superior and inferior frontal sulci in the MIDDLE FRONTAL GYRUS
It is considered to be responsible for executive functions of the human brain.
What’s the function of the the superior frontal gyrus?
The superior frontal gyrus (SFG) is thought to contribute to higher cognitive functions and particularly to working memory (WM)
Where is the inferior frontal gyrus and what is its function?
Located in between the inferior frontal sulcus and the lateral sulcus
Inferior frontal gyrus can be split into:
- pars orbitalis
- pars triangularis
- pars opecularis
The inferior frontal gyrus has a number of functions including the processing of speech and language in Broca’s area
Where’s the cingulate gyrus and what’s its function?
Medial side of the frontal lobe
The anterior portion of the adjoining cingulate gyrus is considered to be the seat of motivation.
Regulation of aggressive behaviour
Co-ordinates the response to pain
Where’s the orbitofrontal cortex and what is its function?
Located in the orbital gyrus on the inferior frontal lobe
The orbitofrontal cortex is often considered to be the seat of associative learning and decision-making.
Where’s the primary auditory cortex?
The superior temporal gyrus
What’s the function of the inferior temporal gyrus?
The inferior temporal gyrus helps process visual information
What is the interparietal sulcus?
Separates the superior and inferior parietal lobes
What makes up the inferior parietal lobe and what is the function?
The inferior parietal lobe is made of the angular gyrus and supramarginal gyrus and is considered to be important for visuospatial attention
What’s the function of the superior parietal lobe?
Spatial orientation, and receives a great deal of visual input as well as sensory input from one’s hand.
Where is the primary visual (striate) cortex?
Calcarine sulcus in the medial occipital cortex
What % of right handed people have right hemisphere dominance?
What % of left handed people have right hand dominance and what % have bilateral dominance?
In right-handed people, the left hemisphere is mostly dominant. In 10% of right-handed people, the right hemisphere is dominant.
Among left-handed people only about 20% are right
hemisphere dominant, with 64% left hemisphere dominant and 16% showing bilateral dominance.
Where’s the planum temporale and what’s the function?
What asymmetry is seen?
In which condition is asymmetry affected?
Triangular region on the upper surface of the
superior temporal gyrus
-It is important for language processing and is larger on the left than the right hemisphere in 65% brains
In which hemisphere is language processed for most people?
Left hemisphere
Left sided lesion cause aphasia
What’s the Papez circuit?
What’s the fucntion?
hippocampus → fornix → mammillary bodies →
mammillothalamic tract → anterior thalamic nucleus → genu of the internal capsule → cingulate
gyrus → parahippocampal gyrus → entorhinal cortex → perforant pathway → back to
hippocampus
Emotional processing
Outside of Papez circuit what are the other structures of the limbic system?
amygdala, septum, basal forebrain, nucleus accumbens, and orbitofrontal cortex.
What’s the Papez circuit?
What’s the fucntion?
hippocampus → fornix → mammillary bodies →
mammillothalamic tract → anterior thalamic nucleus → genu of the internal capsule → cingulate gyrus → parahippocampal gyrus → entorhinal cortex → perforant pathway → back to hippocampus
Emotional processing
What does the hypothalamus do?
influences neuroendocrine responses
What does the amygdala do?
mediation of emotional responses
plays a role in fear conditioning
What does the hippocampus do?
What’s special about the neurons there?
appears to play an important role in memory processes. It is one of the few brain regions where the continuous production of new neurons is noted even in adult life.
What are the components of the basal ganglia?
striatum - caudate nucleus and putamen
pallidum - globus pallidus internal and external
Putamen and globus pallidus are sometimes called lenticular/lentiform nucleus
The subthalamic nuclei and the substantia nigra are both functionally related to the basal ganglia but are not considered to be a part of this structure
Function of the basal ganglia?
Collection of nuclei that are involved in the planning and programming of movement, and also have a role in the processes by which an abstract thought is converted into voluntary action
Direct pathway - allows voluntary movement (striatum, substantia nigra and subthalamic nuclei disinhibit the thalamus via stopping the disinhibitory action of globus pallidus internal)
Indirect pathway - stops involuntary movement (further inhibition of the thalamus via excitation of the globus pallidus internal)
What are the five important circuits involving the basal ganglia?
- Motor circuit
- Oculomotor circuit
- Dorsolateral prefrontal circuit (executive)
- Anterior cingulate circuit (motivation)
- Lateral orbitofrontal circuit (social intelligence)
What is the nature of basal ganglia dysfunction in OCD?
Volumetric changes and higher blood flow to the caudate nuclei. Increased caudate metabolism in untreated subjects reduces after effective treatment.
ALSO LENTIFORM NUCLEUS
What is the nature of basal ganglia dysfunction in Tourette’s syndrome?
Striatal dopaminergic dysfunction
What is the nature of basal ganglia dysfunction in Huntington chorea?
Degeneration of the striatum (mainly caudate nucleus) & selective loss of GABAergic (inhibitory) neurons
STRIATAL DEGENERATION
What is the nature of basal ganglia dysfunction in Wilsons disease?
Copper deposits in the lenticular nuclei
What is the nature of basal ganglia dysfunction in hemiballismus?
Subthalamic nucleus damage (especially infarction)
What is the nature of basal ganglia dysfunction in CO poisoning?
Acute bilateral anoxic damage to basal ganglia
What is the nature of basal ganglia dysfunction in Parkinsonism?
Depigmentation of Substantia Nigra; Lewy bodies are seen
Striatal overactivity associated with bradykinesia
What is the nature of basal ganglia dysfunction Fahr’s disease?
Progressive calcium deposition in the basal ganglia. (early onset cases present with schizophreniform psychoses and catatonia; later onset cases exhibit dementia and choreoathetosis)
What’s the function of the hypothalamus?
- The hypothalamus has chemoreceptors that respond to variations in glucose levels, osmolarity, acid balance, etc
- It influences neuroendocrine responses
- It regulates physiological functions such as eating, drinking, sleeping, and temperature regulation
What’s the function of the ventromedial hypothalamus? What might be noted in animals with a lesion of the ventromedial hypothalamus?
What’s the function of the lateral hypothalamus?
The ventromedial hypothalamus acts as the satiety
center (In animals with a lesion of ventromedial hypothalamus hyperphagia and obesity are noted)
The lateral hypothalamus is the feeding center.
Where is the inferior olivary nucleus and what is its function?
The inferior olivary nucleus is located in the brainstem and aids in motor coordination by projecting climbing fibers to the contralateral cerebellar cortex via inferior cerebellar peduncle
What is seen in lesions that affect the olivary nucleus?
Appendicular ataxia due to motor incoordination of the
contralateral arm and leg (unlike cerebellar lesions where ipsilateral motor incoordination is noted)
What’s the function of the cerebellum?
The cerebellum has the important role of preparing a
motor plan and predicting balance needed between
muscle groups to carry out the intended action smoothly.
What are the components of the brainstem?
midbrain, pons and the medulla
What are the superior and inferior colliculi and what are their functions?
superior colliculi - conjugate gaze control
inferior colliculi - auditory source localisation
What are the cranial nerves?
oh oh oh to touch and feel virgin girls vaginas and hymens
Olfactory Optic Oculomotor Trochlear Trigeminal Abducens Facial Vestibular Glossopharyngeal Vagus Accessory Hypoglossal
What are the functions of the cranial nerves?
I Olfactory
II Optic - Relays via thalamus (geniculate body)
III Oculomotor - Supplies four of the six ocular muscles
IV Trochlear - Supplies superior oblique (ocular muscle)
V Trigeminal - Transmits facial sensation and controls jaw muscles
VI Abducens - Supplies lateral abducens (ocular muscle)
INFERIOR OLIVARY NUCLEUS
Inferior olivary nucleus is located in the
brainstem and aids in motor coordination by
projecting climbing fibers to the contralateral
cerebellar cortex via inferior cerebellar
peduncle.
Inferior olivary lesions lead to appendicular
ataxia due to motor incoordination of the
contralateral arm and leg. Patients with
inferior olivary lesions will fail the finger-nose
test, mimicking cerebellar lesion. But unlike
cerebellar lesions that result in ipsilateral motor
incoordination, the contralateral side is affected
in olivary lesions.
VII Facial - Transmits taste sensation and controls facial muscles
VIII Vestibular - Transmits auditory sensation
Cochlear Transmits balance sensation
IX Glossopharyngeal - Motor control of pharynx; parasympathetic control of the parotid gland; taste from the back of the tongue
X Vagus - Motor control of larynx and pharynx; parasympathetic control of the viscera; visceral
sensations
XI Accessory - motor control of neck muscles
XII Hypoglossal - motor control of tongue muscles
Which cranial nerves have sensory, motor or both functions?
some say money matters but my brother says big boobs matter most
Olfactory - S Optic - S Oculomotor - M Trochlear - M Trigeminal - B Abducens - M Facial - B Vestibular - S Glossopharyngeal - B Vagus - B Accessory - M Hypoglossal - M
What are the tracts of the spinal cord?
The dorsal column carries proprioceptive sensory fibres
the anterior and lateral columns are made of ascending spinothalamic tracts carrying touch, pressure,
pain and temperature sensations
What secretes CSF?
CSF is secreted by the choroid plexus in the lateral, third and fourth ventricles and at a rate of 300 ml/day,
which is almost protein free
What’s the route of CSF?
From lateral ventricle to 3rd ventricle via interventricular foramina of Monroe;
From 3rd to 4th ventricle via cerebral aqueduct of Sylvius;
From 4th ventricle to subarachnoid space via foramen of Magendie (single) and foramina of Luschka (two lateral).
What does the internal carotid artery divide to form on entering the circle of Willis?
The internal carotid artery enters the circle of Willis and divides to form the anterior cerebral and middle
cerebral arteries
What does the anterior cerebral artery supply?
The anterior cerebral artery supplies the medial and superior strip of the lateral aspect of the cerebral
cortex up to the parietal/occipital border.
What does the middle cerebral artery supply?
The middle cerebral artery supplies most of the lateral aspect of the cerebral cortex. This includes the Broca’s and Wernicke’s areas in the dominant hemispheres
What does the posterior cerebral artery arise from and what does it supply?
The posterior cerebral artery arises from basilar artery and supplies the inferomedial temporal lobe and the
occipital lobe.
What do the inferior cerebellar arteries and anterior spinal branches of the vertebral arteries supply?
Medulla
Which blood vessels supply the pons?
Pontine branches of the basilar artery
What are some of the feature of carotid system TIA?
•Amaurosis fugax (due to blockade of retinal arteries) •Aphasia •Hemiparesis •Hemisensory loss •Hemianopic visual loss
What are some of the feature of vertebrobasilar TIA?
- Diplopia, vertigo, vomiting
- Choking and dysarthria
- Ataxia
- Alexia without agraphia
- Hemisensory loss
- Hemianopic visual loss
- Transient global amnesia
- Tetraparesis
- Loss of consciousness (rare)
What are the effects of a lesion of the anterior cerebral artery?
Bilateral infarct produces contralateral quadriparesis (legs weaker than arms) and akinetic mutism (ventromedial or cingulate syndrome)
motor dysphasia
sensory loss of contralateral foot and leg
What are the effects of a lesion of recurrent artery of
Huebner (branch of ACA)?
This supplies the head of the caudate nucleus
Lesions initially lead to an agitated, confused state; evolves to akinesia, abulia, with mutism and personality changes
What are the effects of a lesion of the anterior branches of the upper division of the Middle Cerebral Artery?
Planning deficits, impairment of working memory,
and apathy. (DLPFC dysfunction)
What are the effects of a lesion of the Anterior communicating artery?
Akinesia and personality change (orbitofrontal
dysfunction) with a confabulatory amnesia resembling Wernicke-Korsakoff syndrome.
What are the effects of a lesion of the posterior inferior cerebellar artery (PICA)?
Wallenberg’s lateral medullary syndrome.
Acute vertigo with cerebellar signs.
Ipsilateral face numbness, diplopia, nystagmus, Horner’s syndrome and IX/X nerve palsy with contralateral spinothalamic sensory loss and mild hemiparesis.
What are the three types of white matter tracts?
Projection fibers run vertically connecting higher and
lower centers of the brain.
Association fibers interconnect different regions within the same hemisphere of the brain.
Commissural fibers interconnect similar regions in the opposite hemisphere.
What are some important commissural fibers?
Corpus callosum
Anterior commissure (interconnects olfactory bulbs), Posterior commissure (interconnects midbrain pretectal nuclei)
Hippocampal commissure
Habenular commissure (interconnects posterior dorsal thalamic nuclei)
What is the pericallosal artery and what happens in vascular disruption?
derived from the anterior cerebral artery provides blood supply to the anterior and body of corpus callosum
Left sided apraxia and agnosia may be seen in cases
of vascular disruption
What is the splenium? What’s its blood supply? What happens with disruption?
splenium = posterior aspect of the corpus callosum
suppled by posterior cerebral artery
disrupted supply prevents right visual cortex accessing the dominant hemispheric processes such as
language resulting in ALEXIA AND COLOUR ANOMIA
but with preserved ability to copy words as motor
information is relayed via anterior corpus callosum
How many layers is the neocortex made up of?
What are layers 2 and 4?
What are layers 5 and 6?
The neocortex is made up of six layers
Layers 2 and 4 are mainly afferent (receiving inputs) while 5 and 6 are mainly efferent (sending outputs)
Which neurons make up nearly 75% of the cortical
neurons?
The pyramidal neurons
remaining 25% are stellate cells
Which neocortex cell layer does not have stellate cells?
Layer 1
What are the layers of the cerebellar cortex?
The molecular layer consisting of basket cells and stellate cells
Purkinje layer consisting of Purkinje cells
Granular layer consisting of granule and Golgi cells.
What is the function of Purkinje cells?
Purkinje cells form the sole output of all motor coordination in the cerebellum they connect to the deep cerebellar nuclei via inhibitory projections.
They are GABA-ergic neurons
What are Betz cells and where are they found?
Large pyramidal cells called Betz cells are seen in the primary motor cortex.
Betz cells are pyramidal cell neurons located within the fifth layer of the grey matter in the primary motor cortex
What are Betz cells and where are they found?
Large pyramidal cells called Betz cells are seen in the primary motor cortex.
Betz cells are pyramidal cell neurons located within the fifth layer of the grey matter in the primary motor cortex
What are glial cells?
These are cells with supportive metabolic functions;
they also participate in modulating neuronal
functions e.g. via the production of neurosteroids.
What are the three types of glial cells and their functions?
- Astrocytes are the most numerous of the three types. These are star-shaped cells that enable nutrition of neurons, breakdown of some neurotransmitters, and maintaining the blood-brain barrier.
- Oligodendrocytes are seen in CNS (not in peripheral nerves, where Schwann cells replace them). They produce myelin sheaths that help in saltatory conduction (pole to pole jumping), which quicken the process of signal transmission.
- The microglia are descendants of macrophages. They are scavenger cells that clear neuronal debris following cell death.
- Ependymal cells are a special type of glia that
cover the ventricles and facilitate CSF circulation via their ciliary processes.
Where is the blood brain barrier?
What features of the cells make them suitable for this?
The blood- brain barrier is located in endothelial cells
of capillaries of the brain
The brain’s endothelial cells have tight junctions with high electrical resistance providing an effective barrier against molecules.
Which areas of the brain don’t have BBB?
circumventricular organs e.g. subfornical organ, area
postrema (chemo receptor trigger zone), median eminence and posterior pituitary.
What are the dopaminergic pathways of the brain?
Long paths: Nigrostriatal, mesocortical and mesolimbic pathways.
Short paths: Tuberoinfundibular and incertohypothalamic pathway.
What’s the route of the nigrostriatal pathway and what does blockade cause?
Substantia Nigra to striatum and amygdala via medial forebrain bundle
DA deficiency (e.g Parkinson’s) or blockade due
to antipsychotics can cause extrapyramidal side
effects
What’s the route of the mesocortical pathway and what does blockade cause?
Ventral tegmental area (VTA) to cingulate cortex and prefrontal regions via medial forebrain bundle
Low levels of DA or DA blockade in this tract is
associated with negative symptoms (alogia, anhedonia, amotivation and apathy)
What’s the route of the mesolimbic pathway and what does blockade cause?
Ventral tegmental area (VTA) in MIDBRAIN to Nucleus accumbens and hippocampus via medial forebrain bundle
Blockade of DA in this tract produces the desirable antipsychotic effect by controlling positive psychotic symptoms
What’s the route of the tuberoinfundibular pathway and what does blockade cause?
Hypothalamus to the pituitary via portal vessels
Dopamine acts as PIH – prolactin inhibitory
hormone. DA blockade will serve to increase
prolactin levels
What’s the route of the incertohypothalamic pathway and what does blockade cause?
Internal connections within hypothalamus
Disturbed thermoregulation and possibly weight gain
Nominal aphasia (word retrieval failures and difficulty expressing words) can be localised to lesions in which area? What's the blood supply?
The angular gyrus (located on anteriolateral parietal lobe)
blood supply - middle cerebral artery
*angular gyrus is also responsible for normal arithmetical ability
Which area is affected by lesions to the posterior cerebral artery?
Dentate gyrus (hippocampus) - medial temporal lobe
What’s the function of the dentate gyrus?
Involved in the formation of new episodic memories
Which part of the brain is last to mature?
Prefrontal cortex
Where is the lesion likely to be in homonymous superior quadrantanopia?
Damage to Myers loop (inf. optic radiation) - indication of a lesion within the temporal lobe
Which enzyme is exclusively seen in astrocytes?
Glutamate dehydrogenase
What is the function of an endosome?
An endosome is a membrane-bound cellular compartment of the endocytic membrane transport pathway extending from the plasma membrane to the lysosome. Molecules internalized from the plasma membrane are transported via endosomes to lysosomes for degradation; similarly molecules can also be recycled back to the plasma membrane.
Forced utilization behaviour can be a feature of damage to which structure?
Frontal lobe damage (orbitofrontal lobe)
What is included in the prosencephalon?
- Telencephalon, which gives rise to cerebral hemispheres and contains the pallium, rhinencephalon, and basal ganglia
- Diencephalon consisting of thalamus, subthalamus, hypothalamus and epithalamus consisting of the habenular nucleus and pineal gland
What is included in the mesencephalon?
= MIDBRAIN
- Tectum, in turn consisting of the corpora quadrigemina, made up of the superior and inferior colliculi
- Basis pedunculi
- Tegmentum containing the red nucleus, fibre tracts and grey matter surrounding the cerebral aqueduct.
What is included in the rhombencephalon?
- Metencephalon consisting of the pons, the oral part of the medulla oblongata and cerebellum
- Myelencephalon consisting of the caudal part of the medulla oblongata.
Which is seen as a key function of the non-dominant cerebral hemisphere?
Pictorial memory
Which structure separates the two lateral ventricles in the human brain?
In which condition might this be abnormal?
Septum pellucidum
An anomalous splitting of the septum pellucidum may be more common in schizophrenia than in general population (cavum septum pellucidum).
What’s the location of the third ventricle?
lies between thalamus and hypothalamus
What’s the location of the fourth ventricle?
lies above the pons and just below the cerebellum
What links the third and fourth ventricles?
The Aqueduct of Sylvius
The cerebrospinal fluid passes into the subarachnoid space via recesses in which structure?
From 4th ventricle to subarachnoid space via Foramen of Magendie (single medial foramen) and Foramen of Luschka (two, lateral foramina)
Synaptogenesis is at its highest during which of phase of life?
First 2 years of life
Neural crest cells originate from which embryonic structure?
The neural tube (the precursor of the spinal cord)
The embryonic crest cells migrate to numerous locations in the body to form which structures?
(1) the neurons and glial cells of the sensory, sympathetic, and parasympathetic nervous systems
(2) the adrenergic cells of the adrenal medulla
(3) the pigment-containing cells of the epidermis
(4) many of the skeletal and connective tissue components of the head
Which lobe is initially affected in Alzheimer’s disease?
Which brain region?
Temporal lobe Entorhinal cortex (layer II)
What percentage of the brain is occupied by prefrontal cortex?
30%
Lesions in which location can cause dysarthria?
Cerebellum
Also
- basal ganglia
- upper motor neurone lesions of the cerebral hemispheres
- lower motor neurone lesions of the brain stem
What do lesions of left hemisphere produce?
Left hemisphere lesions may produce alexia, agraphia, acalculia, colour anomia without aphasia, Broca’s aphasia, Wernicke’s aphasia and Gerstmann syndrome.
What do lesions of right hemisphere produce?
Right hemisphere lesions may produce constructional apraxia, prospagnosia, autotopagnosia, visual spatial agnosia, anosognosia, receptive amusia, and contralateral neglect.
The internal capsule is supplied by which structure?
Circle of Willis
What’s the embryological origin of microglia?
microglial progenitors arise from peripheral mesodermal (myeloid) tissue
What’s the embryological origin of macroglia?
macroglia (astrocytes and oligodendrocytes) and neuron are derived from neuroectoderm
Mirror neurons are found in which part of the brain?
Inferior frontal cortex
Premotor cortex
mirror neurons explain modelling behaviour
The ventral tegmental area is located in which part of the brain?
The midbrain
Nucleus accumbens forms a part structure of the brain?
Ventral striatum
Which structures are involved in the visual pathway?
The medial fibres of the optic nerve cross in the optic chiasma to join the contralateral optic tract. The lateral fibres of the optic nerve pass through the ipsilateral optic tract. The fibres synapse in the LATERAL geniculate body of the thalamus. From here the optic radiation runs within the posterior part of the internal capsule and terminates in the visual cortex
Which area of the brain is associated with ‘social valuation’?
Orbitofrontal cortex
Which type of neurons has no axons?
Amacrine neurons
Which cells constitute the most common cells of the layer 4 of the cerebral cortex that receives thalamic input?
Stelate cells
What are the cellular components of the cortical layers?
Layer 1 contains no major neuronal cell bodies but glial cells and dendrites from neurons of deeper layers and the horizontal cells of Cajal.
Layers 2 and 3 are composed of small pyramidal cells, whose axons project out of and within the hemispheres.
Stellate and fusiform cells lie in layer 4 and provide local connections and receive ascending fibres from the thalamus.
Layer 5 consists of large pyramidal cells.
What is a synapse and what are the three types?
synapse = junction between two nerve cells
- chemical - Presynaptic neuron releases a chemical molecule on stimulation. This molecule acts on the next neuron to bring on a molecular effect or to propagate the impulse further downstream
- electrical
- conjoint
What’s an action potential?
the brief reversal of electric polarisation of the membrane of a nerve cell or muscle cell ->
part of the neural membrane opens to allow positively charged ions inside the cell and negatively charged ions out
What’s the resting membrane potential of the neuron?
-70mV
What’s the threshold potential of the neuron and what happens then?
- 55mV.
At -55mV, the Na+ channels present at the axon’s initial segment will open. The subsequent Na+ influx causes rapid reversal of the membrane potential from the negative values to +40mV.
When the membrane potential reaches +40mV, the Na+ channels close and the voltage-gated K+
channels open. As K+ ions move out of the axon, the cell membrane gets “repolarized”.
Which neurochemical substances act as mediators of increased appetite?
ghrelin and neuropeptide Y
Which neurochemical substances act as mediators of satiety?
Leptin, cholecystokinin and serotonin
Where is ghrelin synthesised?
Gastric mucosa
Where is leptin synthesised?
Adipose cells
What are the 2 centers that control body temperature in the hypothalamus?
Preoptic anterior hypothalamus acts as a hypothermic center - stimulating the preoptic anterior hypothalamus results in parasympathetic-mediated sweating and vasodilation, resulting in hypothermia
Posterior hypothalamus acts as a hyperthermic center - stimulating the posterior hypothalamus results in sympathetic drive, shivers and vasoconstriction, leading to hyperthermia.
Lesions in which region of the brain reduce the diurnal temperature variation?
median eminence
Which area of the brain plays a crucial role in pain perception?
The thalamus
What is thalamic pain syndrome and what causes it?
contralateral loss of sensation with burning or aching pain triggered by light cutaneous stimulation
occurs in cases of stroke involving thalamoperforating branches of posterior cerebral artery
Which circumventricular organs playing a crucial role in the perception of thirst?
Subfornical organ (SFO) and organum vasculosum of the lamina terminalis (OVLT)
Which circumventricular organs playing a crucial role in the perception of thirst?
Subfornical organ (SFO) and organum vasculosum of the lamina terminalis (OVLT)
The hypothalamic paraventricular nucleus is also involved in the regulation of thirst
What acts as a neurotransmitter to propagate thirst signals to the hypothalamus?
Angiotensin II
How does hypotension stimulate thirst?
through pathways originating from the baroreceptors on aorta and carotid
What’s Kluver-Bucy syndrome?
Bilateral lesions of amygdala and hippocampus results in placidity with decreased aggressive behaviour. Prominent oral exploratory behaviour and hypersexuality. Hypermetamorphosis (objects are repeatedly examined as if they were novel) is also seen
What’s Laurence Moon-Biedl Syndrome?
Obesity and hypogonadism along with low IQ, retinitis pigmentosa, and polydactyly. Diabetes insipidus is also seen. Autosomal recessive with genetic locus at 11q13 in most cases. No hypothalamic lesions have been found.
What’s Kleine-Levin Syndrome?
Compulsive eating behaviour with hyperphagia, hypersomnolence, hyperactivity, hypersexuality and exhibitionism. A hypothalamic abnormality sometimes preceded by a viral illness; often resolves by the third decade of life.
Where does neurogenesis take place?
An active zone of nerve cell production is seen
immediately around the ventricles of the neural tube. This is called a subventricular zone.
Neurons produced here migrate outwards to the cortical plate.
When does neuronal migration takes place?
Neuronal migration takes place in the first 6 months of gestation.
What is radial migration?
Radial migration is the primary mechanism by
which excitatory neurons reach the cortex ( method by which neurons travel from their origin or birthplace to their final position in the brain)
Radial glial cells form scaffolding through their foot processes to guide the migrating neuronal cells. Successive populations of migrating neurons travel past the previously settled neurons (inside out pattern) to form radial stacks of cells (Rakic’s cortical columns).
Which neurons are tangentially migrated?
Most inhibitory interneurons in the external and internal granular layers are tangentially migrated
neurons.
When does myelination begin and when is it complete?
Myelination begins prenatally at around 4th gestational month; it is largely complete in early childhood
(by 2 years), but does not reach its full extent especially in association cortices until late in the third decade of life.
What is synaptic pruning?
Which conditions may be associated with over or under pruning?
By mid-childhood, more neurons and cellular processes are established than required for adult’s brains. Thereafter a process of pruning or synaptic
elimination takes place to select and preserve the most useful while eliminating the unnecessary neuronal connections in the adult’s brain
Excessive or prolonged pruning is associated with schizophrenia, relative under-pruning is implicated in autism
What’s the hormonal output of the anterior pituitary?
o GH - growth hormone
o LH - luteinizing hormone (a gonadotrophin)
o FSH - follicle stimulating hormone (a gonadotrophin)
o ACTH - adreno corticotrophic hormone (corticotrophin)
o TSH - thyroid stimulating hormone (thyrotropin)
o Prolactin
What’s the hormonal output of the posterior pituitary?
o Vasopressin (ADH – antidiuretic hormone) o Oxytocin
What’s the hormonal output of the hypothalamus?
o CRH - corticotrophin releasing hormone
o GHRH - growth hormone releasing hormone
o GnRH - gonadotrophin releasing hormone
o TRH - thyrotrophin releasing hormone
o SST – somatostatin (inhibits GH)
o PIF - prolactin inhibitory factor (dopamine)
What are some of the physical and mental symptoms of hyperthyroidism?
Physical symptoms: Tachycardia, weight loss, heat
intolerance, sweating
Mental symptoms: Anxiety, irritability, poor concentration, agitation, emotional lability.
What are some of the physical and mental symptoms of hypothyroidism?
Physical symptoms: Fatigue, weight gain, cold intolerance, dry skin
Mental symptoms: Depression, reduced activity
(psychomotor retardation), reduced libido and poor memory
What are some of the physical and mental symptoms of hypercortisolism (Addison’s disease)?
Physical symptoms: Apathy, fatigue, and
depression
Mental symptoms: Anxiety, irritability, poor
concentration, agitation, emotional lability.
What are some of the physical and mental symptoms of hypocortisolism (Cushing’s syndrome)?
Physical symptoms: Fatigue, weight gain, cold intolerance, dry skin
Mental symptoms: Depression, mania, confusion, and
psychotic symptoms.
What’s the purpose of the Dexamethasone suppression test?
- To confirm Cushing Syndrome (excess cortisol)
2. To understand the cause
In which psychiatric conditions is DST non suppression seen?
Depression, mania and schizoaffective
disorder.
In addition, a number of major medical conditions, pregnancy, severe weight loss and use of alcohol and certain other drugs
What does the pineal gland secrete?
serotonin (in the day)
melatonin (in the night)
What endocrine changes are noticed during sleep?
Start of sleep – increased testosterone
Slow wave sleep – increased GH & SST; reduced
cortisol
REM sleep – reduced melatonin
Early morning sleep – increased prolactin
What is actigraphy?
used to quantify circadian sleep-wake patterns and to detect movement disorders during sleep; it uses a motion sensor
What are the components of polysomnography?
EEG, electromyogram (EMG), electrooculogram EOG
How long is normal REM latency in adults?
REM latency = time from sleep onset to first REM
~90 minutes
What % of sleep is NREM?
75%
What are the four stages of NREM sleep?
Stage 1 NREM sleep
• 5% of sleep
• Drowsy period. When awoken from this stage one
denies being asleep.
• Shows low voltage theta activity, sharp V waves.
Stage 2 NREM sleep
•45% of sleep
•Shows the development of sleep spindles and K complexes.
Stage 3 NREM sleep
•12% of sleep
•Shows <50% delta waves.
Stage 4 NREM sleep
•13% of sleep
•Shows >50% delta waves.
•Physiological functions are at the lowest
What are the four stages of NREM sleep?
Stage 1 NREM sleep
• 5% of sleep
• Drowsy period. When awoken from this stage one
denies being asleep.
• Shows low voltage theta activity, sharp V waves.
Stage 2 NREM sleep
•45% of sleep
•Shows the development of sleep spindles (waves with upper alpha or lower beta frequency) and K complexes (mediated by thalamocortical circuitry)
sigma waves are sleep spindles
Stage 3 NREM sleep
•12% of sleep
•Shows <50% delta waves.
Stage 4 NREM sleep
•13% of sleep
•Shows >50% delta waves.
•Physiological functions are at the lowest
What are the features of NREM sleep?
- Increased parasympathetic activity (decreased heart rate, systolic blood pressure, respiratory rate, cerebral blood flow)
- Abolition of tendon reflexes
- The upward ocular deviation with few or no movements
- Reduced recall of dreams if awaken (NIGHT TERRORS)
What are the features of REM sleep?
- Increased sympathetic activity (increased heart rate, systolic blood pressure, respiratory rate, cerebral blood flow)
- Autonomic functions are active with penile erection or increased vaginal blood flow
- Increased protein synthesis
- Maximal loss of muscle tone with occasional myoclonic jerks
- Vivid recall of dream if awaken (NIGHTMARES)
What are the EEG features of REM sleep?
low-voltage, mixed-frequency (theta and slow alpha) activity similar to an awake state.
Sawtooth waves are also seen
Which area of the anterior hypothalamus regulates sleep?
suprachiasmatic nucleus - it orchestrates
circadian rhythms and is synchronised by signals
from the retina
What is the ventrolateral preoptic nucleus and what does it do?
sleep switch nucleus
VLPO induces sleep by putting the brakes on the arousal nuclei. People with damage to their VLPO have chronic insomnia.
What are the neurotransmitters of the Ascending Reticular Activating System?
Cholinergic –> Midbrain-pons nuclei REM on neurons –> Activation brings on REM sleep
Noradrenergic –> Locus coeruleus REM off neurons –> Activation reduces REM sleep
Dopaminergic –> Periaqueductal gray matter –> D2 possibly enhances REM sleep
Serotoninergic –> Raphe nuclei –> 5HT2 stimulation possibly maintains arousal
Histaminergic –> Tuberomammillary nucleus –> H1 stimulation possibly maintains arousal
What sleep changes does alcohol cause?
- Increase SWS (chronic use – loss of SWS)
- Reduce initial REM but increase second half REM
What sleep changes does alcohol withdrawal cause?
- Loss of SWS
- Increased REM
- Intense REM rebound
What sleep changes do anxiety disorders cause?
- Increased stage 1 sleep (light sleep)
- Reduced REM, normal REM latency
- Reduced slow wave sleep
What sleep changes do benzos cause?
- Decrease sleep latency
- Increase sleep time
- Reduce stage 1 sleep
- Increase stage 2 sleep
- Reduce REM and SWS
- REM rebound on cessation
- Prevent the transition from lighter stage 2 sleep into deep, restorative (stages 3 and 4) sleep
What sleep changes does cannabis cause?
- Increase SWS
- Suppress REM
What sleep changes does carbamazepine cause?
- Suppresses REM and increases REM latency
- Increases SWS
What sleep changes does dementia cause?
- Increased sleep latency & fragmentation
- Reduced sleep time
What sleep changes does depression cause?
- Loss of SWS slow wave sleep (first half)
- Increased REM (leading on to Early awakening)
- Reduced REM latency
What sleep changes does lithium cause?
- Suppresses REM and increases REM latency
- Increases SWS
What sleep changes do opiates cause?
- Decrease SWS & REM
- Withdrawal REM rebound
What sleep changes does schizophrenia cause?
- Inconsistent reduction in REM latency and slow wave sleep
NB: Antipsychotics have variable effects
What sleep changes do SSRIs cause?
- Alerting due to 5HT2 stimulation
- May reduce REM latency
- Variable effects of REM suppression
What sleep changes do stimulants cause?
- Reduce sleep time by decreasing both REM sleep and SWS
- REM rebound on cessation (except modafinil)
What sleep changes do TCAs cause?
- REM suppression (especially Clomipramine)
- Increased SWS and stage 1 sleep
What sleep changes do Z hypnotics cause?
Less effect on sleep architecture; Zopiclone may increase SWS
What are the different EEG waves and their frequencies?
-Delta <4 Hz
Not seen in waking EEG. Common in deeper stages of sleep; the presence of focal/generalized delta in awake EEG is a sign of pathology.
-Theta 4 to 8 Hz
A Small amount of sporadic theta seen in waking EEG at frontotemporal area; prominent in drowsy or sleep EEG. Excessive theta in awake EEG is a sign of
pathology.
- Mu 7-11 Hz
Occurs over the motor cortex. It is related to motor activity, characterized by arch like waves; gets attenuated by movement of the contralateral limb - Alpha 8 to 13 Hz
Dominant brain wave frequency when eyes are closed and relaxing; occipitoparietal predilection. Disappears with anxiety, arousal, eye opening or focused attention.
Dominance reduces with age.
-Sigma 12-14Hz (loss of these in fatal familial insomnia)
- Beta >13Hz (12-30)
Some seen at frontal, central position in the normal waking EEG
-gamma 30-100Hz
- Lambda Single waves
A single occipital triangular, symmetrical sharp wave produced by visual scanning when awake (e.g. reading) or in light sleep
What’s the most common cause of secondary amenorrhoea?
The most common cause of secondary amenorrhoea is pregnancy.
Which classes of drugs slow beta activity?
Antipsychotics and antidepressants
Which classes of drugs have little effect on EEG?
Anticonvulsants, analgesics, beta blockers and narcotics
By which age are EEG changes notable in Angelman syndrome?
In Angelman syndrome, EEG changes are notable by the age of 2.
Prolonged runs of high amplitude 2-3 Hz frontal activity with superimposed interictal epileptiform discharges are seen in all ages
Occipital high amplitude rhythmic 4-6 Hz activity facilitated by eye closure is seen under the age of 12 years.
Infants have a dominant rhythm in which EEG wave frequency?
3 Hz
What is the duration of normal sleep latency in healthy adults?
15-20 minutes
What percentage of epileptic patients will have normal EEG between attacks?
30-50%
By what age is the normal dominant EEG rhythm achieved?
The normal dominant alpha rhythm is usually achieved by 12-14 years old.
In which brain region is the dominant EEG alpha rhythm seen?
The dominant alpha rhythm is seen posteriorly in the occipito-parietal region
What reduces the EEG alpha rhythm?
Opening the eyes, concentrating, arousal states and anxiety usually abolishes the dominant alpha rhythm.
Which EEG rhythm is almost always abnormal in adults?
Ongoing delta activity is almost always abnormal in the adult
Orexin (hypocretin) neurons are dysfunctional in which disorder?
Narcolepsy
Flattened trace of EEG is a feature seen in which condition?
Huntington’s disease
Which ions are freely permeable across cell membranes?
Chloride
Regular 3 Hz complexes are seen in EEG of patients with which of condition?
Absence seizures
Which stages of sleep are considered as slow wave sleep?
Stage 3 and 4 n-REM sleep
Which disorder is associated with low levels of cortisol?
PTSD
Which disorder is characterised by a predominant presence of triphasic waves in EEG?
hepatic encephalopathy.
also associated with a wide range of toxic, metabolic, and structural abnormalities
What are the characteristics of the EEG in sposradc CJD?
The classic EEG finding in CJD is generalized 1-2 Hz bi- or triphasic sharp- and slow-wave complexes.
Which receptor on stimulation leads to sleep onset?
Cholinergic
Peak cortisol level in normal physiological states is seen at what time of day?
6-7am
Generalised spike-wave discharges with decreased waves on photic stimulation are seen in EEG of patients with which condition?
Generalised seizures (myoclonic epilepsy)
There is a nocturnal surge in the level of growth hormones during which stages of sleep?
Stage 3 and 4 n-REM sleep
Which brain region when stimulated via magnetic pulse reduces depression?
Left prefrontal
Which physiological changes are noted after ECT in clinically depressed individuals?
Reduced ß receptors
Increased noradrenaline turnover is also noted.
An EEG showing high amplitude repetitive bilaterally synchronous symmetrical polyphasic sharp wave and slow wave complexes, which occur every 4-15 seconds are characteristic of which condition?
Sub acute sclerosing pan encephalitis
Which neurotransmitters are monoamines?
Histamine Acetylcholine Serotonin Epinephrine (adrenaline) Norepinephrine (noradrenaline) Dopamine
Which neurotransmitters are monoamines?
Histamine Acetylcholine Serotonin Epinephrine (adrenaline) Norepinephrine (noradrenaline) Dopamine
Which neurotransmitters are amino acids?
Glutamate
Glycine
GABA
Which neurotransmitters are peptides?
Ghrelin Leptin Neuropeptide Neurotensin Cholecystokinin Endorphins
What are the three types of receptors?
(1) Ligand-gated channels (ionotropic) - in which binding of a chemical messenger alters the probability of opening of transmembrane pores or channels
FAST RESPONSES
(2) Metabotropic - Those in which the receptor proteins are coupled to intracellular G proteins as transducing elements
SLOW RESPONSES
(3) Ligand-dependent regulators of nuclear transcription (nuclear receptors)
What’s the source of dopamine?
tyrosine -> l dopa -> dopamine
Which enzymes break down dopamine?
- Monoamine oxidase (MAO) & Catecholomethyltransferase (COMT)
- MAOQA”more”selectively”metabolizes”norepinephrine”and”serotonin
- MAO-B more selectively metabolises dopamine
The neural mechanism of memory formation may include changes in physical properties of neurons and synapses. One such change called LTP or Long Term Potentiation is mediated by which receptor?
NMDAhas a role in memory acquisition, developmental plasticity, epilepsy, and ischemic brain injury. NMDA receptor mediates long-term potentiation
What is the most abundant neurotransmitter in the median raphe nuclei?
Serotonin
Which substance serve as a precursor for GABA?
Glutamate
Which type of glutamate receptor is crucial for the normal function of inhibitory interneurons?
NMDA
The Nucleus of Meynert is a prominent site of localization for which neurotransmitter in the brain?
Acetylcholine
Which receptors increase adenylate cyclase to stimulate cell machinery?
Beta adrenergic
What are carrot-shaped eosinophilic inclusions seen in hematoxylin and eosinophilic stains?
Rosenthal fibres
- diagnostic signature of Alexander’s leukodystrophy
The principal location of noradrenergic neuronal cell bodies in the CNS is at which site?
Locus coereleus
What are the neurochemical changes in the brain reported in Alzheimers disease?
Decreased levels of acetylcholinesterase (AChE), decreased levels of choline acetyltransferase, decreased GABA levels
decreased levels of noradrenaline
Glycine and d-serine both act as co-agonists at which receptor?
NMDA
An enzyme involved in synthesis of acetylcholine is
Choline acetyl transferase
Which is a rosette shaped receptor?
NMDA
What’s the source of serotonin?
Tryptophan –> 5 hydroxy l-tryptophan –> serotonin
Which serotonin receptors is a ligand-gated cation channel?
5HT3
What is the enzyme involved in catabolism of GABA?
GABA transaminase.
The predominant CNS metabolite of noradrenaline is?
Outside the CNS?
MHPG (3-methoxy,4-hydroxy phenyl glycol)
Vanillyl mendalic acid (VMA)
Stimulation of nicotine receptors leads to the release of which neurotransmitter?
Dopamine
Where do phospholipids get produced in a cell?
Smooth endoplasmic reticulum
What is the rate-limiting step in the synthesis of dopamine?
Tyrosine Hydroxylase
D1 and D2 receptors are mainly located in which structures?
Caudate-putamen
Which neurotransmitter plays an important role in the neurochemical changes seen in Huntington’s disease?
GABA
What are the signs of Gerstmann’s syndrome?
Which lobe dysfuntion isit?
Dominant parietal lobe
finger agnosia (loss in ability to name or recognise specific fingers on the patient’s own or on others hands)
dyscalculia (an impaired ability to perform mental arithmetic)
dysgraphia (inability to write)
right-left disorientation (inability to carry out instructions that involve an appreciation of the right and left)
What are the signs of non dominant parietal lobe dysfunction?
anosognosia (lack of awareness of a disability or disease) dressing apraxia (difficulty in getting dressed) spatial neglect (lack of awareness of one side of the body) constructional apraxia (inability to copy pictures or combine parts of something into a meaningful whole)
What are the signs of bilateral parietal lobe dysfunction?
What’s another name for it?
Bilateral damage to the parietooccipital lobe (at the junction of the two) is rare but can result in a condition called Balint’s syndrome. This is characterised by:-
ocular apraxia (difficulty keeping the eyes still) optic ataxia (difficulty moving the eyes to a specific position) simultanagnosia (inability to simultaneously perceive the different aspects of a picture and appreciate it as a whole)
What is Kluver-Bucy syndrome? What are the signs?
Bilateral medial temporal lobe dysfunction
Hyperorality (tendency to explore object with the mouth) Hypersexuality Docility Visual agnosia Dietary changes
What are some causes of Kluver-Bucy syndrome?
Herpes Late stage Alzheimer's Frontotemporal dementia Trauma Bilateral temporal lobe infarction
Where do the cranial nerves originate and exit from?
1 Olfactory O:Telencephalon E: Cribiform plate
2 Optic - O: Diencephalon E: Optic foramen
3 Oculomotor - O: midbrain E: Superior orbital fissure
4 Trochlear - O: midbrain E: Superior orbital fissure
5 Trigeminal - O: pons E: Superior orbital fissure (ophthalmic V1) Round foramen (maxillary V2) Oval foramen (mandibular V3)
6 Abducens - O: pons E: Superior orbital fissure
7 Facial - O: pons E: internal auditory canal
8 Vestibulocochlear - O: pons E: internal auditory canal
9 Glossopharyngeal - O: Medulla E: Jugular foramen
10 Vagus - O: Medulla E: Jugular foramen
11 Accessory - O: Medulla E: Jugular foramen
12 Hypoglossal - O: Medulla E: Hypoglossal canal
What is the function of the cranial nerves?
1 Olfactory - Sense of smell
2 Optic - Vision (Pupillary light reflex S Accommodation reflex M)
3 Oculomotor - Eye movement, pupillary constriction, lens accommodation (Pupillary light reflex M, Accommodation reflex M Vestibulo-ocular reflex M)
4 Trochlear - Eye movement (Vestibulo-ocular reflex M)
5 Trigeminal - Chewing, sensation of anterior 2/3 of scalp, tenses tympanic membrane (jaw jerk reflex M/S, Corneal reflex S)
6 Abducens - Eye movement (Vestibulo-ocular reflex M)
7 Facial - Facial expression, taste anterior 2/3 of tongue, tension on stapes (Corneal reflex M)
8 Vestibulocochlear - Hearing (Vestibulo-ocular reflex S)
9 Glossopharyngeal - Taste posterior 1/3 of tongue, elevation of larynx and pharynx, swallowing (Gag reflex S)
10 Vagus - Swallowing, voice production, parasympathetic supply to nearly all thoracic and abdominal viscera (Gag reflex M)
11 Accessory - Shoulder shrugging and head turning
12 Hypoglossal - Tongue movement
Which pathological findings support a diagnosis of multisystem atrophy?
Macroscopic features:
Pallor of substantia nigra
Greenish discolouration and atrophy of the putamen
Cerebellar atrophy
Microscopic features:
Papp-Lantos bodies (alpha-synuclein inclusions in oligodendrocytes found in the substantia nigra, cerebellum, and basal ganglia)
*associated Parkinson’s symptoms respond poorly to l-dopa
What are the pathological findings in Alzheimer’s?
Macroscopic changes seen in Alzheimer’s include:-
Hippocampal atrophy
Cerebral atrophy
Low brain weight
Enlargement of the inferior horn of the lateral ventricle
Microscopic changes seen in Alzheimer’s include:-
Senile plaques (extracellular deposits of beta amyloid in the gray matter of the brain)
Neurofibrillary tangles (intracellular composition of HYPERphosphorylated tau protein)
Gliosis
Degeneration of the nucleus of Meynert
Hirano bodies (eosinophilic inclusion bodies)
What are the connections of the basal ganglia?
The cortex projects to the striatum, the striatum to the internal segment of the globus pallidus, the internal segment of the globus pallidus to the thalamus and the thalamus back to the cortex, thus creating a loop.
Which nerve fibres are unmyelinated?
C
What are the four nerve fibre types and what info do they transmit?
A-alpha (proprioception)
A-beta (touch)
A-delta (pain and temperature)
C (pain, temperature, and itch)
This hormone has a paracrine effect and inhibits the release of hydrochloric acid.
Somatostatin
This hormone is secreted by the cells in the duodenum when they are exposed to the acidic contents of the emptying stomach
Secretin
This hormone stimulates the exocrine cells of the stomach to secrete gastric juice
Gastrin
Which neuroimaging finding is most suggestive of new variant CJD?
Pulvinar sign - increased signalling in the pulvinar of the thalamus bilaterally on MRI
What are some examples of inotropic receptors?
GABA-A 5HT-3 Nicotinic acetylcholine receptors Glutaminergic (NMDA) Glycine
What are some examples of metabotropic receptors?
GABA-B Serotinergic receptors (except 5HT-3) Muscarinic acetylcholine receptors Dopaminergic Adrenergic
What re the three areas of the cerebellum and their functions?
Vestibulocerebellum (balance and spatial orientation)
Spinocerebellum (fine-tuned body movements)
Cerebrocerebellum (involved in planning movement, and the conscious assessment of movement)
What separates the cerebellum from the brainstem?
What separates the cerebellum from the cerebrum?
Cerebellar peduncles
tentorium cerebelli
What’s the EEG in delirium?
Diffuse slowing, decreased alpha, increased theta and delta
What’s the EEG in delirium tremens?
Hyperactive trace, fast
What’s the EEG in Alzheimer’s?
Reduced alpha and beta, increased delta and theta
What’s the EEG in normal aging?
Diffuse slowing, which can be focal or diffuse, if focal most commonly seen in the left temporal region
Which structure transmits the middle meningeal artery?
Foramen spinosum in the Middle fossa
Which structure transmits the Internal carotid artery?
Foramen lacerum in the middle fossa
Which structure transmits the Spinal cord?
Foramen magnum in the posterior fossa
What are the earliest neuropathological changes that occur in Alzhemer’s?
The earliest neuropathological changes occur in the medial temporal lobe, which include hippocampal atrophy and changes to the parahippocampal gyrus.
In which condition has the characteristic EEG pattern of sharp spikes at 25-30Hz?
Grand mal epilepsy (generlised epilepsy)
Approximately 20% of patients with Autism have which feature?
Macrocephaly
The retina develops from which area of the embryonic brain?
Diecephalon
Alexia without agraphia is usually caused by an occlusion of which artery?
PCA (affects corpus callosum)
What are the effects of MCA occlusion?
Hemiparesis of the contralateral face and limbs
Sensory loss of contralateral face and limbs
Dysphasia (when dominant hemisphere affected)
Contralateral neglect
Homonymous hemianopia or quadrantanopia
What are the effects of PCA occlusion?
Alexia without agraphia (left PCA)
Contralateral loss of pain and temperature sensation
Contralateral hemianopia
Prosopagnosia
Ipsilateral cranial nerve defects (V, VIII, IX, X, & XI)
Horner’s syndrome
The ventromedial prefrontal cortex is believed to be crucial for what?
moral judgement
What’s the function of the fusiform gyrus?
Involved in face recognition (Prosopagnosia results from dysfunction)
Which gyrus is involved with dreaming?
Lingual gyrus
Which lesion would be most likely to result in bitemporal hemianopia?
Pituitary
Which ions cause presynaptic vesicles to release neurotransmitter into the synaptic cleft?
Calcium
Which street drug blocks the monoamine transporter SERT?
Amphetamine
A lesion in which cranial nervewill result in a hoarse voice and dysphagia?
Vagus
The diagnosis of which condition is supported by an abnormal tonsillar biopsy?
vCJD
Which are the symptoms of Anton-Babinski syndrome?
Which area of the brain does brain damage occur?
Affected individuals are cortically blind but are unaware of this and deny they have a problem (anosognosia). It often presents as the patient starts falling over furniture as they can’t see. Affected individuals believe they can still see and describe their environments in detail but are wrong in their description (confabulation).
occurs following damage to occipital lobe
What’s the serotonin receptor involved in circadian rhythms?
5HT7
Damage to which structures is thought to cause the emotional changes seen in dementia pugilistica?
Mamillary bodies
Which hormone secereted by the gastrointestinal tract stimulates hunger?
Ghrelin
Which hormone secreted by the gastrointestinal tract (stomach) stimulates hunger?
Ghrelin
What connects the lateral geniculate nucleus to occipital (primary visual) cortex?
geniculocalcarine tract
In which condition are zebra bodies found?
Tay Sachs
In which condition are Mallory bodies found?
Wilson
Knife blade atrophy is seen in which condition?
Pick’s disease
Which disease can be studied by inducing ‘autoimmune encephalomyelitis’?
MS
In those with Mild Cognitive Impairment, which biomarker can detect worsening cognitive function?
Increased Tau-to-Amyloid ratio in CSF
The pathological factor that correlates most with cognitive decline in Alzheimer’s disease is?
Burden of neurofibrillary tangles
White matter hyperintensities seen in mood disorders are associated with what?
vascular risk factors
In which condition is both balloon cells and Hirano bodies are seen?
Pick’s disease
The immunological staining used in detection of Pick’s disease is?
Anti-tau
The spongiform appearance of brain tissue in CJD is due to
Neuropil vacuolation
What are the neuropathological findings in Punch Drunk syndrome?
neuronal loss and neurofibrillary tangles
Which hormone secreted by the intestine and acts as an appetite suppressant?
Cholecystokinin
What is the septum pellucidum?
in which condition is it damaged?
a membrane separating the anterior horns of the left and right lateral ventricles of the brain
Damaged in Dementia pugilistica
What is the most common type of primary brain tumour in adults?
1) Metastatic tumours
2) Glioblastoma multiforme
3) Anaplastic astrocytoma
4) Meningioma
What is the most common type of primary brain tumour in children?
1) Astrocytoma
2) Medulloblastoma
3) Ependymoma
Nitric oxide has been suggested as playing an important role in the pathogenesis of which condition?
Depression
Which drugs increase alpha and theta activity waves in the EEG?
Stimulants
Antipsychotics
Which drugs decrease alpha waves in the EEG?
Alcohol
Opioids
Benzos
What results from damage to the arcuate fasciculus?
Conduction aphasia
The term ‘intrinsic activity’ used to describe drug/receptor interactions is also known as?
Efficacy
The receptor of which inhibitory neurotransmitter is antagonised by strychnine leading to strychnine poisoning?
Glycine
What is charcterised by the triad of Parkinsonism, cerebellar ataxia, and autonomic failure?
Multisystem atrophy
Which drugs increase alpha waves in the EEG?
Cannabis
What are the monoamine neurotransmitters?
Serotonin, Dopamine, Norepinephrine
What are the amino acid neurotransmitters?
Glutamate, Glycine, GABA
What are the peptide neurotransmitters?
Cholecystokinin, Endorphins, Angiotensin
Which enzyme is located on the postsynaptic membrane?
Acetylcholinesterase
Which enzyme breaks down GABA?
Transaminase
Which enzyme breaks down serotonin and noradrenaline?
MAO A
Which enzyme breaks down dopamine?
MAO B
COMT
What is the breakdown product of Dopamine?
Homovanillic acid
What is the breakdown product of norepinephrine?
Vanillyl mandelic acid
What is the breakdown product of serotonin?
5-hydroxyindole acetic acid,
What is the breakdown product of acetylcholine?
Choline
What are the main functions of: Acetylcholine Dopamine Serotonin GABA Noradrenaline
Acetylcholine – Learning Dopamine – Motivation Serotonin – Feeding GABA – Anxiety Noradrenalin– Arousal
Which serotonin receptor is responsible for:
Regulation of circadian rhythm
Antiemetic effect
Anxiogenic and anorexic effect
Antidepressant action due to agonistic effect Antimigraine effect
Regulation of circadian rhythm – 5HT7 Antiemetic effect – 5HT3 Anxiogenic and anorexic effect – 5HT2C Antidepressant action due to agonistic effect – 5HT1A Antimigraine effect – 5HT1D
Which serotonin receptor is responsible for:
Regulation of circadian rhythm
Antiemetic effect
Anxiogenic and anorexic effect
Antidepressant action due to agonistic effect Antimigraine effect
Regulation of circadian rhythm – 5HT7 Antiemetic effect – 5HT3 Anxiogenic and anorexic effect – 5HT2C Antidepressant action due to agonistic effect – 5HT1A Antimigraine effect – 5HT1D
What are the signs of medial prefrontal syndrome?
Poverty of speech , Paucity of spontaneous behaviour
What are the signs of orbitofrontal syndrome?
Poor impulse control, Explosive outbursts
What are the signs of dorsolateral prefrontal syndrome?
Executive dysfunction, Diminished planning
What is the midbrain structure of visual tract connected to the thalamus?
Superior colliculi
Arcuate fasciculus connects Broca’s area with which structure?
Wernicke’s area
What is the thalamic nuclei of the auditory system connected to midbrain?
Medial geniculate body
Uncinate fasciculus connects temporal lobe to which structure?
Inferior frontal gyrus
Planning and programming of movement is controlled by which part of the brain?
Basal ganglia
Preparing a motor plan and predicting balance is controlled by which part of the brain?
Cerebellum
Where is the entorhinal cortex situated?
What does it do?
The entorhinal cortex is situated in the temporal lobe
*functions as a hub in a widespread network for memory, navigation and the perception of time
Enlargement of which structure can be seen as a consequence of long-term treatment with haloperidol? –
Corpus striatum ( Dopamine receptor occupancy (D-2) in the corpus striatum predicts response to antipsychotics. It also plays an important role in causing akathisia and other extrapyramidal side effects caused by antipsychotics)
