Neuroscience Post-Midterm Flashcards
Lower motor neuron
Motor neuron that communicates directly with somatic muscle
Upper motor neuron
Motor neuron that arises from motor centers in the brain that communicate with lower motor neurons directly or through local interneurons
Pyramidal motor system
Corticolspinal tract (ventral medulla)
Paralysis
Complete loss of motor function due to lesion of neurons or muscle
Plegia
Paralysis
Paresis
Subparalytic muscle weakness
Hemiparesis
Partial paralysis on one side of the body
ALS
Amyotrophic lateral sclerosis is a progressive NM disease that initially affects and later destroys lower motor neurons and eventually parts of the corticospinal/bulbar tracts and primary motor area
Classic presentation: 50% cases begin in hand; loss of muscle bulk thenar, hypothenar, interossei, arm/shoulder
Symptoms: Weakness and difficulty speaking/swallowing
Pts. require ventilation/gastronomy; reduction cough reflex (aspiration pneumonia), fasiculations/weakness tongue
Unaffected: sphincter control, sensory function, intellect
Prognosis: death 3-5 years after diagnosis; death from respiratory insufficiency and aspiration pneumonia
ASA syndrome
Cause: ASA infarction, less commonly: tumor, epidural abscess
Symptoms: Spastic paraparesis, bilateral extensor plantar response, bilateral loss pain, temp below, touch/vib/prop in tact, retention of urine, sexual functions imparied
* ASA supplies anterior 2/3 spinal cord
Lesion: 2nd order motor neurons in anterior horn, ALS, Corticospinal tracts (lateral and anterior)
* Rare, can cause paraplegia (damage of LMN in anterior horn) and lateral Corticospinal tract (UMNS’s)
* Bladder, lung infections, PE, pressure sores
Central medullary syndrome
Cause: Syringomyelia, tumor, hemorrhage
Pathological cyst in central canal; cervical involvement
* Develops anterior; pressure to anterior horns and anterior white commissure
* Segmental muscle atrophy (muscles of hand/fingers); loss of pain/temperature due to destruction of anterior white commissure
*Other symptoms: pain/weakness, stiffness in back, arms, shoulders, legs; disturb sweating, sexual function and bladder/bowel control
Which descending tracts are concerned with flexion vs. extension?
Flexion: Doral/Lateral; lateral corticospinal, rubrospinal, medullary lateral reticulospinal
Extension: Anterior/Medial; (lat+medial) vestibulospinal, pontine medial reticulospinal
Where is the lateral corticospinal tract located in the spinal cord?
Lateral horn
All motor pathways, except the _________________ tract ends at synapses on LMN in the spinal cord or on interneurons
Corticobulbar
Name the descending motor pathways
Cortical – CS, CB
Subcortical – Rubrospinal, reticulospinal, vestibulospinal
Where are the descending motor fibers for the proximal vs. distal muscles?
Proximal: medial
Distal: lateral
Which of the motor pathways is involuntary?
Vestibulospinal (medial-medulla+pons and lateral-pons)
Damage to corticobulbar fibers innervating the facial nucleus results in…
Contralateral lower facial paralysis (upper facial nucleus is innervated by both ipsi/contra-lat
Damage to corticobulbar fibers to the hypoglossal nucleus results in…
Contralateral deviation of the tongue
A central lesion of PPRF results in…
Deviation of eyes towards the side of the lesion
A unilateral internal capsule infarction results in…
Contralateral UMN syndrome
Differentiate between the pre-frontal, pre-motor and primary motor cortices
Pre-frontal: planning, social restraint
Pre-motor: motor programs
Primary motor: Strong excitation LMN
Differentiate between simple, complex and imagined motor tasks
Simple: Primary motor, primary sensory
Complex: Pre-motor (supplementary-medial) & primary motor
Imagined: Supplementary-medial
> 90% of ______________________ fibers decussate in the ventral medulla
Corticospinal
> 90% of ______________________ fibers decussate in the ventral medulla
Corticospinal
Spinal shock
Flacidity, areflexia several weeks following a lesion to a motor tract
Spinal shock
Flacidity, areflexia several weeks following a lesion to a motor tract
Paraplegia
Bilateral s/c lesion; UMN below the lesion
UMN’s release _________________ onto ____________ receptors of LMN’s or interneurons
Glutamate; AMPA
Brown-Sequard Syndrome
Ipsilateral UMN, DC/ML below
Contralateral: ALS below
Segmental LMN @ level lesion
Brown-Sequard Syndrome
Ipsilateral UMN, DC/ML below
Contralateral: ALS below
Segmental LMN @ level lesion
Paraplegia
Bilateral s/c lesion; UMN below the lesion
UMN’s release _________________ onto ____________ receptors of LMN’s or interneurons
Glutamate; AMPA
From where does input come for the motor cortex?
Premotor, somatosensory, posterior parietal, BG, cerebellum
Decerebrate posturing
A lesion at or caudal (below) the red nucleus impairs CS, CB, Rubrospinal
Patient extends upper and lower limbs
* 2 GCS points
Decortiate posturing
A lesion rostral (above) the red nucleus that impairs CB and CS fibers
- Flex the upper limbs and extend the lower limbs (following a noxious stimulus or spontaneously)
- 3 GCS points
Who is responsible for tuning of the intrafusal muscle fibers?
Gamma motor neuron
Specialized aggregations of _______________ fibers form muscle spindles.
Intrafusal fibers
The pontine reticulospinal tract primarily innervates alpha/gamma motor neurons.
Gamma
The ____________________ tract primarily innervates gamma motor neurons.
pontine reticulospinal
The rubrospinal pathway…
Is it contralateral or ipsilateral?
From where does its input come?
Flexion in the upper limbs
* Excites alpha and gamma motor neurons
** Contralateral
Input: ipsilateral motor cortex, contralateral cerebellar nuclei
The medullary reticulospinal pathway…
Is it contralateral or ipsilateral?
Flexion limbs
- Contra + Ipsilateral
- Bilateral cortical input
The pontine reticulospinal tract…
Ipsilateral or contralateral?
Ipsilateral
The lateral pontine vestibulospinal tract innervates which motor neurons?
Alpha
** Axial and limb
The medial vestibulospinal tract innervates motor neurons in an excitatory or inhibitory manner?
Inhibitory (glycine)
** Cervical and upper thoracic
Differentiate between cervical/neck & axial/limb innervation among the lateral and medial vestibulospinal tracts.
Cervical neck: medial
Axial/limb: lateral
Intrafusal fiber
Specialized muscle fiber within a muscle spindle
Extrafusal fiber
Muscle fiber located outside of muscle spindles forming the bulk of the muscle
Motor neuron pool
All motor neurons innervating a given muscle
How do you test for hypotonia?
Reduced muscle tone; detectable by palpation and testing resistance to passive stretch of the limb.
Damage to either the 1a afferent or alpha motor neurons will reduce muscle tone, yielding hypotonia and flaccid paralysis
Can also arise from lesion in other parts of the motor system, even when alpha motor neurons and 1a afferents have been spared
Myotatic reflex
A reflex whereby stretching of a muscle provokes contraction of the same muscle. It is mediated by a monosynaptic connection between 1a afferents and alpha motor neurons
Inverse myotatic reflec
A reflex where muscle relaxation is evoked by increased tension developed in the same muscle. Mediated by 1b afferents and alpha motor neurons
The conduction velocity of a nerve is dependent on…
Myelination (faster) and diameter (faster)
Muscles involved in fine movement have more density/less density of muscle spindles.
More density
With respect to Group 1A and 2 sensory neurons, what is the difference between the type of stretch that they sense.
1A: static + dynamic (rate of change of length): static nuclear bag, nuclear chain + dynamic nuclear bag
2: static (static nuclear bag, nuclear chain)
What fibers are in series with the extrafusal muscle fibers?
Golgi tendon organ fibers
What type of afferent fiber innervates the golgi tendon organ?
1B (unmyelinated on the inside)
Who is responsible for the “inverse myotatic” reflex and what is the reflex?
Golgi tendon organ; at very high levels of tension/over-active alpha-motor neurons, the golgi tendon relaxes the agonist muscle and excites the antagonist muscle
What are Renshaw cells?
Inhibitory interneurons innervated by alpha motor neurons
Motor neuron pools are derivatives of the alar/basal plate?
Basal
Where is the greatest density of lower motor neurons in the S/C? (2 locations)
Cervical and lumbar
Motor neurons receive input from 3 different types of neurons.
- Muscle spindle afferents
- Local interneurons
- Upper motor neurons
What is the formal definition of a motor unit?
Alpha motor neuron and the extrafusal fibers that it innervates
Each alpha motor neuron controls how many extrafusal muscle fibers for: (a) postural; (b) ocular: 1, 10, 100, 1000?
Postural: 1000
Ocular: 10
Approximately how many motor neurons control a single muscle?
100
Differentiate between types I, IIA, IIB motor units.
I: slow-twitch, low tension, aerobic, low number of nerves
IIa: fast twitch; 1/2 aerobic
IIb: fast twitch; anaerobic, large number of motor neurons
What are the two major factors that control skeletal muscle contraction?
- Firing rates
2. Motor units recruited
What types of motor disorders can cause muscle weakness?
All!
What types of motor disorders can cause muscle atrophy?
All but NMJ disorders
What types of motor disorders can cause fasiculations?
Motor neuron damage
What types of motor disorders can cause a reduction in conduction velocity?
Schwann cells
What types of motor disorders can cause fluctuations in amplitude of EMG?
NMJ
EMG consisent with denervation…
Motor neuron or Schwann cell disorders
What is Myotonia congenita?
Cl- channel syndrome; smaller stimulus for depolarization – prolonged repetitive firing even without stimulus
What is the difference in distribution of nAChR in embryo vs adult?
Embryo: widely spread out
Adult: concentrated
2 congenital myasthenias
Deficiency in ACh-esterase
Slow channel syndrome
What condition is associated with a “facilitating neuromuscular block”
Lambert-Eaton syndrome
Polio destroys…
cell body of lower motor neuron
What is a characteristic sign of cortical damage?
Aphasia
T/F The primary motor cortex handles movements of individual muscles.
False – that is the role of the lower motor neuron
Acute stage motor lesions can cause…
Flaccid paralysis
What are the 4 types of tremor?
- Physiological
- Resting – BG/Parkinson’s
- Kinetic (intention) – cerebellum – when moving
- Essential/Postural – with a certain posture
What is chorea?
Involuntary, jerky movements (as in choreography)
What is ballismus? Where is the lesion?
Flinging, rotating
*Sub-thalamus
What is athetosis?
Slow writhing of fingers, toes, hands
How do we assess gait?
Walk straight path (heel-to-toe) or heel or toe; turn smoothly
How do we assess station?
Feet together, eyes closed
How do we assess posture?
Muscle tone; decortiate/decerebrate
Chorea is most associated with these 2 diseases
Huntington disease
* Sydenham disease (childhood rheumatic fever)
Describe the 5 stages of Parkinson’s
- Unilateral
- Bilateral with posture
- Bilateral without posture
- Sever disability/with falls
- Akinesia
Describe the features of Parkinson’s disese
(TRAPS) Tremor (resting tremor) Rigidity Akinesia Postural changes (stooped) Stare (serpentine stare) · To remember what kind of tremor and postural change, can look at letter that follows in TRAPS: Tremor is Resting, Posture is Stooped.
What is spasmodic torticollis?
Dystonia/muscle spasm
What is tardive dyskinesia?
Drug induced oral movements (dopamine receptor antagonists)
What are the major hyperkinesia disorders?
Parkinson’s
Drug induced Parkinson’s
Vascular - Strokes interrupting the nigrostriatal pathway may cause parkinsonism,
affecting both direct and indirect pathways
Dementia pugilistica - trauma
Post-encephalitic
Neoplastic
What are the major hypokinesia disorders?
Huntington Sydenham Disease (Autoimmune)
Drug-induced Chorea
Athetosis
Hemiballismus
How is Huntington disease treated?
Treatment: D2 antagonists, VMAT inhibitor
Describe drug-induced Parkinsons
Phenothiazines, which block D2 receptors in the forebrain in the treatment
of psychosis (or hyperkinesis), may cause parkinsonism by limiting
dopamine-mediated inhibition of striatal neurons contributing to the
indirect pathway
• Drugs that deplete dopamine stores within nerve endings (e.g. reserpine)
may diminish striatal dopaminergic transmission to affect both the direct
and indirect pathways, thereby producing parkinsonism
• A metabolite of MPTP, a contaminant produced during improper
preparation of a synthetic narcotic, causes parkinsonism by damaging
nigral mitochondria
Describe several treatmens for Parkinson’s
Treatments
L-dopa, D2 agonist, dopamine enhancers, Anticholinergics, MAOI/COMTi, Ablative surgery (subthal or GPI), deep brain stimulation (thal, GPI)
An infarct to the vestibulocerebellum
•Disturbances affect equilibrium-related motor functions
o Nystagmus (ocular ataxia)
o Tilted head
o Titubation (head-nodding)
o Truncal ataxia (imbalance) with compensatory wide-based stance.
Disturbance to the spinocerebellum
Disturbances affect posture and movement of limbs
o Ataxias of the limbs common (ipsilateral)
•Gait ataxia accompanied by lurching to the side of the lesion
Disturbance to the cerebrocerebellum
Disturbances affect accuracy and timing of movement o Ataxia o Decomposition of movement o Dysarthria (slurred monotonous speech) o Dyssynergia (uncoordination of limbs) Dysdiadokinesia (inability to perform rapidly alternating movements) Dysmetria (past-pointing) o Hypotonia o Intention tremor o Rebound phenomenon
Louis-Bar Syndrome
- Autosomal recessive disorder with widespread degeneration of cerebellar Purkinje cells and compromised immune function (chromosome 11)
- Delayed development of motor skills accompanies increased vulnerability to infection
- Most obvious signs relate to walking, talking, facial and ocular movements
- On the longer term, sensitivity to ionizing radiation is observed along with increased vulnerability to cancers
- Skin and eyes tend to express small dilated blood vessels
Cerebellar cognitive affective syndrome
•Lesions of the posterior lobe are considered (by some) to correlate with failures of cognitive and emotional systems, leading to:
o Emotional blunting and depression, disinhibition, and psychotic features
o Executive, visual-spatial, and linguistic deterioration
•The condition is conceptualized in relation to “dysmetria of thought,” suggesting a larger role for the cerebellum in cortical control
Dementia pugilistica
Parkinson’s secondary to trauma
Define muscle tone
Force with which a muscle resists being lengthened
Define spasticity
A hypertonic state with increased deep tendon reflexes
Define falccidity
Weak, lax and soft muscle, without resistance to passive movement
Define clonus
Rhythmic palpable oscillations between flexion and extension
When a muscle is passively stretched, it reflexively
contracts
Biceps reflex
C5, 6, 7
Triceps reflex
C6, 7, 8
Knee-jerk reflex
L2, 3, 4
Ankle-jerk reflex
S1, 2
Differentiate between 0, 1+, 2+, 3+, 4+ reflex scale
0 - no response 1+ - weak 2+ - normal 3+ - high normal 4+ - brisk with clonus
Anal sphincter reflex
S2, 3, 4
What is the objective of the Golgi Tendon Organ relfex
Protection of muscle/tendon; maintenance of posture
What is the flexion reflex?
Noxious stimulus (A-delta and C fibers) causes ipsilateral flexion, and contralateral extension
Positive Babinski Sign
Extension of big toe (dorsiflexion) often accompanied by fanning of other toes
* Problem with lateral CS tract
Which response is slower: myotatic or inverse myotatic?
Inverse myotatic
Dysarthria
Slurred, monotnous speech
Dyssynergia
Uncoordinated limbs
Dysdiadokinesia
Inability to perform rapidly alternating movements
Dysmetria
Past-pointing (Finger-to-nose)
Alcoholics are at risk of this cerebellar dysfunction
Anterior cerebellar lobe; degeneration of Purkinje cells; motor signs
Vermis/Paravermis/Lateral hemispheres of the cerebellum communicate with which deep nuclei?
Fastigial/Interposed/Dentate
HTLV infection can causes (in addition to leukemia)
Tropical spastic paresis (demyelination of S/C)
Paresthesia
Morbid/abnormal sensation (burning, prickling, pins/needles, numbness)
Ephapse
Pathological contact between parallel nerve fibers where electrical nerve impulses can leak from one fiber to the other
Guillan Barre
Acute inflammatory polyneuropathy (begins distal) following an infection
Leprosy
Profound sensory loss (pain/temperature)
Preferentially unmyelinated axons
Hansen disease
Profound sensory loss (pain/temperature)
Preferentially unmyelinated axons
Lead poisioning
Motor loss in fingers/arms
Encephalopathy/Memory loss
No sensory loss
Alcoholic polyneuropathy
Symmetrical motor and sensory loss
* Numbness, tingling, burning in feet
Diabetic neuropathy
Symmetric sensory (starts), asymmetric motor loss *Stocking distribution
Differentiate between negative loss and positive gain (with respect to neuropathy)
Loss: weakness, tendon reflexes, ANS, impaired sensory
Gain: Paresthesia, pain
Motor neuron soma, peripheral nerve, demyelination, axonal degradation, NMJ
* Any sensory/motor NCV damage?
Peripheral nerve & Demyelination
3 major type of nerve trauma
- Compression
- Crush
- Axotomy
Describe axotomy
- Wallerian degradation – distal axon
- Anterograde degredation – distal n. cell
- Retrograde degradation – proximal n. cell
Describe regeneration of nerves in the PNS
Axonal sprouting, lingering Schwann cells
- NGF, laminin, adhesion molecules
- 1mm/day
Describe regeneration of nerves in the CNS
Not possible; oligodendrocytes do not secrete NGF
What is gliosis?
A scar formed by astrocytes; a mechanical barrier to sprouting axons
Axons differentiate into nerve terminals when they contact…
The basal lamina
T/F Inner parts of the nerve are more vulnerable to damage compared to outer parts, i.e. the epinerieum
True
Complex regional pain syndrome
Neuropathic pain secondary to resolved injury of bone, soft tissue, nervous tissue
*Increased sympathetic output; hyperhidrosis, sensitization to NE
Hirschsprung disease
Congenital decrease in motility/peristalsis of the distal colon
Lack of Mesiner’s and Auerbach’s plexuses
-Trapped feces dilation
Sympathetic T1-T2
Superior cervical ganglion (face, eyes)
Sympathetic T2-T6
Inferior cervical ganglion/upper thoracic (upper extremity, heart, bronchi)
Sympathetic T6-L1
Celiac ganglion (liver/GI)
Sympathetic T9-L1
LS plexus; lower extremeity
Sympathetic T10-L1
Adrenal gland
Sympathetic T11-L1
SMG
Sympathetic L1-L2
IMG
Parasympathetic: CN 3, 7, 7, 9, 10, S2-4
CN3: EW nucleus -- ciliary CN7 SS nucleus -- PT/SM CN9 IS nucleus -- Otic CN10 Dorsal motor nucleus (bronchial tree, heart, GIT) S2-4: rectum, bladder, repro
Differentiate between pathological hypothermia/hyperthermia
Hypothermia: damage to posterior
Hyperthermia: damage to anterior
Diabetes insipidus
Damage to supraoptic/paraventricular nuclei, no ADH, excessive thirst
* Treatment: ADH agonist
Frolich syndrome
Lesion to medial thalamus (unopposed lateral hunger stimulation)
Hypothalamus: feeding
Medial: satiety
Lateral: hunger
Hypothalamus: h2o balance
ADH, angiotensin receptors, vagal afferents
Name the 6 anterior pituitary hormones and their hypothalamic control hormones
DA -inhib-> Prolactin GHRH --> Growth hormone GnRH --> FSH/LH CRH --> ACTH TRH --> TSH
Parvo/magnocellular with respect to hypothalamus (anterior vs. posterior)
Parvo: anterior
Magno: posterior
Milk ejection: prolactin or oxytocin?
Oxytocin
Functions of hypothalmus
Temperature/Thirst Apetite Libido Emotion/Emergency BP/Electrolytes
Horner’s syndrome
Loss of sympathetic input to the head (unilateral ptosis, miosis, anhydrosis, facial flushing)
*Pre-ganglionic/Post-ganglionic; hypo-spinal (entire 1/2 of body)
Atonic bladder
Interruption of urinary reflex arc; sensation of fullness is lost; dribbling and loss of reflexive emptying
Automatic bladder
Supra-sacral spinal cord lesion
*Bladder fills until a threshold and then spontaneously, reflexively empties
Sleep-wake cycles in blind people
Lack of visual input (zeitgeber); mismatch in circadian rhythm
Suprachiasmatic nucleus
Light-sensitive retinal cells (optic nerve/chiasm)
* Also reaches pineal gland
T/F Humans have a free-running biological clock which nearly lines up with a 24 hour day
True (approximately 25 hours)
T/F Hypothalamo-spinal fibers can contribute pupillary dilation
True
Describe the 3 levels of innervation of the bladder. Which is most important clinically?
Parasympathetic
- Supratentorial (frontal lobe, hypothal)
- Subtentorial (pontine micturition center)
- Spinal (T/L sympa – S2-4 para)
Stretch receptors in the bladder can influence neurons in 3 different places
- DRG –> Sympa/Para
- Pons
- Cortex
Androgen insensitivity syndrome
Mutated androgen receptor
Testicular feminization; act like XX’s
Primary amenorrhea, female distribution of fat
Fetal exposure to DES
Synthetic estrogen (++ homosexuality "DES daughters") in the 50's Enlarged SDN in females
When is the sexual “critical period” during development
Weeks 12-20
Are testosterone and estradiol required for male sexual development?
Yes
Homosexuals have a larger _______________ and smaller _____________.
Larger: Suprachiasmatic
Smaller: INAH3 (interstitial nucleus of the anteror hypothalamus)
Differentiate between the James-Lange and Cannon-Bard theories of emotion
Lange: express then feel
Cannon: feel than express
Describe the modern concept of the limbic system
Cortex, cigulate, hippocampus, hypothalamus, anterior thalamus
Kluver-Bucy
Bilateral removal of the amygdala; flat emotions, hyper-orality, hypersexual (temporal lobe lesion)
Describe the fear conditioning experiment
Remove amygdala –> no fear
Describe the different roles of the amygdala and the hippocampus in regulating a physiological stress response
Amygdala: enhanced response
Hippocampus: dampened response
A tumor in this location can induce olfactory and gustatory hallucinations
Temporal lobe
T/F Direct input to the amygdala can lead to immediate defensive behavior
True
The motor pathway that is required for fine control of digits of the hand is the:
Lateral corticospinal
Identify the cortical region involved in the planning of a complex sequence of movements that will cluminate in rising from a seated position, wlking across the room, opening and exiting a door, walking down a hall, turning left, and opening a refrigerator.
Prefrontal
The chart of a patient states that he has a right uncal herniation due to a right intracerebral hypertensive hemorrhage. Which of the following neurological deficits would you find upon examination?
Left extensor plantar response
Sympathetic sweat gland receptors: Muscarinic or Nicotinic?
Muscarinic
Treatment Schizophrenia
Typical: Haldol, D2 antagonist
Atypical: D3, D4 antagonist (less Parkinson-like motor side effects)
Describe the relationship between schizophrenia and Parkinsons
Inverse; hence treatment for one can induce the other
Define dysthymia
Less severe form of depression
Treatments for depression
MAOI, 3cyclic, SSRI
Functional imaging of mania
Pre-frontal cortex below the genu of the corpus callosum (increased activity with mania; decreased activity with depression)
Dyslexia
Developmental or secondary; read words backwards
Alexia
Word blindness, can’t read L visual field; disruption of transfer to the left hemisphere; damage to splenium corpus callosum
Aphasias
Fluent Wernicke's Transcortical sensory Gerstmann (written) Conduction (can understand, can't repeat -- L superior temporal)
Nonfluent
Broca’s
Transcortical motor
Global (B+W+Conduction)
What is prosody?
Pattern intonation – grammatical role, sarcasm, emotion
Where is emotion (L or R)
R
Where is language center (L or R)
L
Incoming spoken word is processed
Wernicke
Outgoing spoken word
W, B
Reading
W
Writing
W, B
When does language develop?
5-7 months: language like sounds 7-8 months: syllables 1-2 year: first word 2 year: rich phrases 3 year: correct words and grammar
Agraphia
Writing
A lesion to the angular gyrus
Gerstmann Syndrome (can’t comprehend written)
Lesion to secondary association cortex
transcortical sensory aphasia
Lesion to arcuate fasiculus
Conduction aphasia
Lesion to left dorsolateral frontal
Transcortical motor aphasia
A 17 year old female patient of yours has never had a period. That is odd because she has developed all of the other secondary sex characteristics. During examination you notice the absence of axillary & pubic hair.
Androgen insensitivity syndrome
X-recessive; mutation in testosterone receptor
- What enzyme is responsible for converting testosterone into estrogen?
Aromatase
Where is the estradiol receptor located?
Cytosol
What region of the brain has the highest number of estradiol receptors?
Hypothalamus
The use of what synthetic estrogen in the 1940s-1970s to prevent spontaneous abortion led to a higher incidence of bisexual & homosexuality in girls?
DES [Diethylstilbestrol]
When is the critical period of sexual differentiation
12-20 weeks gestation
Testosterone producing cells
Leydig cells
On what chromosome is the gene for testis determining factor?
Y
3 brain regions that exhibit sexual dimorphism
- Corpus callosum
- Anterior commussure
- Hypothalamus
Which hypothalamic nucleus is not sexually dimorphic?
Arcuate
Which thalamic nucleus is 1/2 the size in homosexual men vs. heterosexual men? INAH 1, 2, 3, 4
INAH 3
Which hypothalamic nucleus is responsible for reducing feeding behavior? Paraventricular or Ventromedial
Ventromedial
Which hypothalamic nucleus is 2x as large in males vs. females?
INAH1, SDN
Which hypothalamic nucleus is 2x as large in homosexual men vs. heterosexual men?
Suprachiasmatic nucleus
Anatomical changes during a manic/depressive episode
Depressive phase: Reduced activity in area of prefrontal cortex below the genu of the corpus callosum
Manic phase: Increased activity in area of prefrontal cortex below the genu of the corpus callosum
This subgenul region is important for mood states & has connections w/ other regions involved in emotion [amygdala, lateral hypothalamus, nucleus accumbens, NorE, serotnergic, dopaminergic systems of the brain]
Dysthmia
Less severe form of depression
How long does it generally take before anti-depressive medications show their effects?
3-4 (sometimes 8 weeks)
Antipsychotics that have almost no side effects on the extrapyramidal system?
Clozapine, olazapine
D3/4 receptor antagonists
Clozapine, olazapine
Mood stabalizers
Carbamacepine, Lamotrigine, Lithium, Valproate
Typical anti-psychotic drugs
Haldol, perphenazine
These drugs can have tardive dyskinesia as side effect
Haldol, perphenazine
Anatomical anomolies seen in schizophrenics
*Reduced blood flow to left globus pallidus
(Disturbance is system connecting basal ganglia to frontal lobes)
*Blood flow does not increase in frontal lobes during tests of working memory:
*Cortex of medial temporal lobe is thinner & the anterior portion of the hippocampus is smaller than in normal people: memory defects
*Lateral & 3rd Ventricles are enlarged & reduced volume of temporal & frontal lobes:
Individuals with these types of schizophrenic symptoms have the worst prognosis
Negative
Would you characterize a schizophrenic w/ grossly disorganized or catatonic behavior as having positive, negative, or disorganized symptoms?
Negative
What are the prodromal signs of a psychotic episode?
Social isolation & withdrawal, Impairment in normal fulfillment of expected roles, Odd behavior & ideas, Neglect of personal hygiene, Flat affect
What types of hallucinations are most common in schizophrenics?
Auditory
3 major classes of symptoms in schizophrenics
Positive symptoms: Additional pathological symptoms
Negative symptoms: Loss of function [presence indicates poorer prognosis]
Disorganized symptoms: Disorder of thought & memory dysfunction & confusion
The ventral tegmentum releases…. onto the ___________________.
Dopamine; nucleus accumbens
People that are genetically prone to addiction have what difference in NT activity compared w/ people that don’t?
Seem to have a general reduction in serotonin [5-HT]
How did Cloniger describe his two “types” of addiction?
Type 1: Low novelty seeking, High harm avoidance, High reward dependence
Type 2: High novelty seeking, Low harm avoidance, Low reward dependence
Ketamine is a stimulant/sedative/hallucinogen
Hallucinogen
Out of hallucinogens, sedatives & stimulants, which drugs cause psychological dependence?
All
Out of hallucinogens, sedatives & stimulants, which drugs cause physical dependence?
Sedatives
What change in what NT results in psychotic symptoms in alcohol withdrawal?
Dopamine
What change in what NT results in epileptic seizures in alcohol withdrawal?
Glutamate
What drug is used most often in the treatment of alcohol withdrawal?
Benzodiazapenes
What are more serious symptoms of alcohol withdrawal?
Marked tremor [the shakes], Delirium [psychomotor agitation, confusion, optic hallucinations], Seizures, Hallucinations May result in death
Can opiate withdrawal cause death?
No
What are the symptoms of opiod detox?
GI flu (nausea, tachy) * Warm or Cold (methadone)
EEG is used to assess:
Brain death, Brain damage, epilepsy, sleep
Awake, active & thinking individuals w/ open eyes
Background frequency of awake person or closed eyes
- Alpha/Beta; Frontal/Posterior
Awake, open eyes: beta, frontal
Awake, closed eyes: alpha, posterior
When your waves have a lower frequency than they should they are known as?
Slow waves [the slower the wave the more severe the abnormality]
Epilepsy is a chronic condition of…
Repetitive seizures
What are some drugs that enhance the activity of GABAergic receptors & are used in the treatment of epilepsy?
Barbs & Benzos
An aura precedes a partial or generalized seizure?
Partial
A seizure that has a focus in one part of the brain and remains in a localized region is known as a…
Partial epileptic seizure
- Negative LOC
What are two drugs used in the treatment of epilepsy that work by REDUCING the # of Na+ channels? Phenytoin, Carbamazepine
Phenytoin, Carbamazepine
Todd’s paralysis
Brief period of transient (temporary) paralysis following a seizure
Which of the seizures are also known as Petit-Mal seizures? Absence typical or absence atypical
Absence typical
Absence typical or atypical
Gradual/sudden
Typical: sudden
Atypical: gradual
Grand mal seizure characteristics
Tonic-Clonic-Post-tictal
Seizures can be classified into 2 general categories. What are they?
Primary
Secondary (Focal or generalized)
* Localized = partial; start local, then spreads = 2econdary generalized and LOC
What is the difference between a simple partial and complex partial seizure?
Simple: No LOC
Complex partial: Aura
A petit mal, or absence seizure…
specific pattern of generalized convulsion - brief (usually seconds); no movement (except maybe eye blink or lip movement), no loss of tone; no memory for time; no postictal period; it is most common in children and may be “outgrown.
Ampa receptors, phosphorylation
GluR1, GluR2
Hippocampus, cerebellum
LTP, LTD
Hippocampus: GluR1, phosphorylation, LTP
How are NMDA receptors activated in the brain with respect to memory?
Increased AMPA conductance, receptors, synapses
Alzheimers brains can show…
Senile amyloid plaques (ECF)
ICF – tangles/tau proteins, granulovascular degeneration
