General prac study 2 Flashcards
During prenatal development, the procencephalon divides into the ______ and the _______, which then subdivide into the thalamus, hypothalamus and retina and the cerebrtal cortex and basal ganglia respectively
During prenatal development, the procencephalon divides into the diencephalon and the telencephalon.
The hypothalamus receives a major input from the ____
The hypothalamus receives a major input from the amygdala
What is one of the ways the hypothalamus regulate behaviours essential for homeostasis and reproduction such as eating, drinking, sexual and maternal behaviours, and processes such as growth?
By regulating hormonal excretions to the pituitary gland
The suprachiasmatic nucleus (“nucleus over the chiasm”), receives direct input from the retinae and regulates circadian rhythms. Where is it found?
The suprachiasmatic nucleus is found in the hypothalamus
Which space holds the mamillary bodies?
The interpenduncular fossa
The pituitary gland is attached to the hypothalamus by the ____
The pituitary gland is attached to the hypothalamus by the infundibulum
The pineal gland (‘jetlag gland’), which produces melatonin, receives light information indirectly from the retina via which nucleus?
The pineal gland (‘jetlag gland’), which produces melatonin, receives light information indirectly from the retina via suprachiasmatic nucleus of the hypothalamus
The habenula and pineal gland are both found above the thalamus. Therefore, they form the ______
The habenula and pineal gland are both found above the thalamus. Therefore, they form the epithalamus
What is the choroid plexus, what does it do and where is it found?
The chroroid plexus produces CSF, it’s found in the lateral and 4th ventricles
Loss of pigmentation in the substantia nigra is indicative of what disorder?
Parkinsons
Along with the hypthalamus, the thalamus forms part of the wall of which ventricle?
Along with the hypthalamus, the thalamus forms part of the wall of the 3rd ventricle
The anterior nucleus, the mediodorsal nucleus, the pulvinar, the medial and the lateral geniculate nuclei are all visible on the surface of which major nucleui hub?
The anterior nucleus, the mediodorsal nucleus, the pulvinar, the medial and the lateral geniculate nuclei are all visible on the surface of the thalamus
The largest nucleus of the thalamus, which is an important component of the visual attention network, particularly in initiating saccades and orienting the head to visual stimuli is the _____
The largest nucleus of the thalamus, which is an important component of the visual attention network, particularly in initiating saccades and orienting the head to visual stimuli is the pulvinar
The brachia (plural for brachium- arm) connect which structures?
The brachia connect the superior collicus with the lateral geniculate nucleus and the inferior colliculus with the medial geniculate nucleus
What kind of information does the internal capsule transmit?
The internal capsule transmits motor and sensory information to and from the cortex
This structure, part of the limbic thalamus, projects information to the cingulate cortex via the mammillary bodies. It is the ____ ____
This structure, part of the limbic thalamus, projects information to the cingulate cortex via the mammillary bodies. It is the anterior tubercle
The fornix connects the hippocampus to the _____ and the _____
The fornix connects the hippocampus to the thalamus and the hypothalamus
Which gyrus is between the inferior temporal gyrsu and the parahippocampal gyrus?
the fusiform gyrus is between the inferior temporal gyrus and the parahippocampal gyrus
Which part of the cerebellum forms the lowest part of the brain, and sits just above the foramen magnum?
What does this part look like?
The cerebellar nodules form the lowest part of the brain, sitting just above the foramen magnum.
The cerebellar tonsils look like flaps
The nucleus accumbens, the merger of the head of caudate and the putamen, is associated with what type of process?
The nucleus accumbens is associated with reward and learning
What are the 5 regions of the cerebellum?
The 5 regions of the cerebellum are:
-Vermis
- Flocculus
- Nodule
- Anterior lobe
- Posterior lobe
The 5 regions of the cerebellum can be divided into 3 functional groups: Spinocerebellum, vestibulocerebellum and cerebrocerebellum.
Which regions belong to which group, and what are the general inputs for each group?
The vermis belongs to the spinocerebellum group, it’s input if proprioceptive information (eg dorsal columns, spinocereblellar and CNV).
The flocculus and nodule belong to the vestibulocerebellar group. Their input is vestibular and eye movement.
The anterior and posterior cerebellar lobes belong to the cerebrocerebellar functional group. They receive cortical input.
There are 5 destinations for the retinal ganglion cells, and only one relates to conscious vision perception. What is it, and where is it located?
The retinal ganglion destination that relates to the special sense vision is the LGN of the thalamus
What are the 4 destinations of the retinal ganglion projections (into 2 parts of the midbrain, the thalamus and the hypothalamus) which relate to unconscious processes?
- The suprachiasmatic nucleus of the hypothalamus
- The superior colliculus of the midbrain
- The pretectal nucleus of the midbrain (projects to CNIII for reflexive eye movement and light information)
- The pulvinar of the thalamus (saccades, maintain direction of head during eye movement etc)
Major neuronal myelination occurs during development until what age?
Major neuronal myelination occurs during development until mid 20s
What is the mesoderm?
Progenitor of the vertebral column formed in mesoderm; ie, the notochord becomes the spinal chord
____ _____ ____ migrate to form peripheral nervous system components:
cranial, dorsal root & autonomic ganglia, Schwann cells,
meninges, bones and muscles of the head
Neural crest cells migrate to form peripheral nervous system components:
cranial, dorsal root & autonomic ganglia, Schwann cells,
meninges, bones and muscles of the head
What is the difference between the ventricular zone and the sub-ventricular zone in neural development?
The ventricular zone gives rise to evolutionarily older structures (deep grey nuclei such as the thalamus), whereas the sub-ventricular zone gives rise to the cerebral cortex.
How does neuronal migration differ across the ventricular and the sub-ventricular zones and when does neuronal birth take place?
Neuronal birth takes place when final neuronal division is complete (mitosis). The neurons of the sub-ventricular zones utilise more active migration up radial glial tracks to the cerebral cortex, whereas cells in the ventricular zone divide and bulge out
What is meant by ‘inside-out’ lamination in cortical neuronal migration?
Layer VI is the first cortical layer to form, then neurons crawl past to each successive layer, after which the sub-plate and radial-glial template is eliminated (cell death)
The notochord induces formation of the ____ ____
The notochord induces formation of the neural plate
Name the 3 vesicles which emerge from the neural tube
The rhombencephalon, mesencephalon and procencephalon,
Name the 5 vesicles which emerge from the 3 vesicles
Procencephalon-> Telencephalon & diencephalon
Mesencephalon-> mesencephalon
Rhombencephalon-> Melencephalon & myelencephalon
What happens to the vesicles once all the brain tissue has been formed?
What are they vesicles formed by?
They form the ventricles. The vesicles are formed by the neural tube
spinal cord lesions will always cause _____ damage, except for the spinothalamic tract
spinal cord lesions will always cause ipsilateral damage, except for the spinothalamic tract
Where do neuronal axons found in the ventral horn originate, and where do they decussate?
M1. They decussate in the pyramidal decussation
How much of the brain is hidden in the sulci (on the ‘banks’)?
About 2/3 of the brain is hidden in the sulci. Only 1/3 is visible on the surface
What’s the main job of the Na+/K+ pump?
The main job of the sodium potassium pump is to maintain the resting potential (-65mV) of the neuron
What is ATP?
ATP provides the energy necessary for the Na+/K+ pump to maintain the resting potential across the neuronal axon
What happens when a Ligand-binding –neurotransmitter
receptor opens channels on the post-synaptic neuron?
When a ligand-binding neurotransmitter binds to a post-synaptic neuron, the ligand-gated ion channel opens to receive the binding neurotransmitter vesicle/s, which in turn triggers an AP in the post-synaptic neuron
Are GABA synapses and glutamate (GLU) synapses symmetrical or asymmetrical?
GABA synapses are symmetrical; they have equal synaptic density on each side of the synaptic cleft, whereas glutamate synapses are asymmetrical, with a higher density of synapses on the post-synaptic side.
Where are the highest density of ligand-gated and voltage-gated ion channels distributed across the neuron?
The highest density of ligand-gated channels is at the dendrites whereas the highest density of voltage-gated channels is at the axon hillock and axonal membrane. They are most dense near the axon hillock, where the AP begins
Ligands are ________ (not exclusively, but importantly for this course)
Ligands are neurotransmitters
After an AP has propagated down the axon, what process ensures that the resting potential is regained?
The sodium potassium pump
What triggers depolarisation at the axon hillock?
The opening of Na+ voltage gated channels causes the depolarisation at the axon hillock, beginning an AP
What happens to the post-synaptic neuron when the neurotransmitter binds to the ligand-gated channel?
When the neurotransmitter binds to the ligand-gated channel, it opens and allows sodium (Na+) to enter, which in turn prompts AP in the post-synaptic neuron
Who was the first to notice the laminae?
Bradmann
Neuronal processing underlies processes such as thought. This is an example of the ____ _____.
Who first came up with this?
Neuronal processing underlies processes such as thought. This is an example of the neuronal doctrine.
Ramon y Cajal
What is LTP (long term potentiation), and how does it affect dendritic spines?
LTP is the consolidating of memories over time. Dendritic spines are altered in that there are more numerous spines and they have greater surface area as memories are strengthened
What’s the difference between implicit and explicit memory? Which is procedural and which is declarative?
Explicit memory is declarative, which means that I can recount these memories (declare them).
Implicit memory is procedural, which means things like riding a bike or driving, I’m not aware of the process of remembering
What are engrams?
Engrams are lasting neuronal connections which result from simultaneous excitation
a memory trace
What is a memory trace?
A memory trace is the product of an engram; simultaneous neuronal excitement which represents a particular memory
How does LTP’s (long term potentiation) affect on dendritic spines compare to brain development during gestation?
In both processes, the dentritic spines are creating more complex and intertwined networds
Which medial temporal lobe structures direct memory consolidation?
The entorhinal cortex and the hippocampus direct memory consolidation
\_\_\_\_\_\_ memories are localised to modality-specific cortex (e.g. visual, auditory) and association cortex. Specific areas (hippocampus & entorhinal cortex) direct the storage of declarative memories. Areas such as dorsolateral prefrontal cortex direct strategies for storing and retrieval.
Declarative memories are localised to modality-specific cortex (e.g. visual, auditory) and association cortex. Specific areas (hippocampus & entorhinal cortex) direct the storage of declarative memories. Areas such as dorsolateral prefrontal cortex direct strategies for storing and retrieval.
Once a memory has become hippocampaly remote (nb also entorhinally remote), where is it stored?
It’s spread over the modality-specific areas and association areas
Which area directs strategies for memory storage and retrieval, once that memory is hippocampally (and entorhinally) remote?
The dorsolateral prefrontal cortex directs the storage and retrieval of hippocampally remote memories, which are now stored across modality-specific areas and association areas
What is the mantra of memory retrieval?
“It’s all in the connections”
Sensory memory, STM (short term memory) and LTM (long term memory) are all features of what type of memory?
Sensory memory, STM (short term memory) and LTM (long term memory) are all features of declarative memory
Patient HM underwent a bilateral temporal labectomy. How did this affect him?
Since he no longer had an entorhinal cortex or hippocampus, he suffered anterograde memory loss; he was unable to form any new memories.
He also had part of his neocortex in the temporal lobe removed, which affected some of his LT memories, but more were intact.
What type of memory are the basal ganglia and cerebellum responsible for?
The cerebellum and basal ganglia are responsible for procedural memories
How does the subiculum bridge the entorhinal cortex and the hippocampus?
The subiculum relays information between the entorhinal cortex and the hippocampus
What is prosopagnosia, and what causes it?
Prosopagnosia is loss of memory for faces, caused by damage to the fusiform gyrus (occipitotemporal)
What is the main interface between the hippocampus and the cortex? How does this structure communicate with the hippocampus?
The entorhinal cortex is the main interface between the hippocampus and the cortex. The subiculum carries information from the entorhinal cortex to the hippocampus
Memory lives in the connection between the _____ and the hippocampus
Memory lives in the connection between the cortex and the hippocampus
The following are all examples of _______ _____ _____ during axonal path finding :
● SLIT secreted proteins, control midline repulsion, dual role, signaling through roundabout receptors (Robo)
● Ephrins (A +B) membrane anchored, repellent and attractive functions, receptors: EphA, EphB
●Netrins and their receptors
●Semaphorins 5 different subfamilies characterized by a 500 aa semaphorin domain, secreted and anchored. Cell Adhesion Molecules ( N-CAM, L1 or Fasciclins)
The following are all examples of molecular guidance molecules during axonal path finding :
● SLIT secreted proteins, control midline repulsion, dual role, signaling through roundabout receptors (Robo)
● Ephrins (A +B) membrane anchored, repellent and attractive functions, receptors: EphA, EphB
●Netrins and their receptors
●Semaphorins 5 different subfamilies characterized by a 500 aa semaphorin domain, secreted and anchored. Cell Adhesion Molecules ( N-CAM, L1 or Fasciclins
Netrin is used to ____ the growth cone across the commissure at the floor plate (ventral side) of the spinal cord
Netrin is used to attract the growth cone across the commissure at the floor plate (ventral side) of the spinal cord
The glial wedge supports the axons across the ____ _____
The glial wedge supports the axons across the corpus callosum
The following 4 stages are involved in ________
1) Synaptic pre-patterning: Cell intrinsic processes that contribute to pre-establishment of synaptic components
2) Coordinated morphological and structural changes: Dendritic filopodia motility
3) Contact stabilization:Triggered by cell-to-cell ligand-receptor interactions and intra-cellular signaling cascades
4) Synaptic refinement: Activity-mediated strengthening or weakening of connections. Activity-mediated refinement of topography.
The following 4 stages are involved in synaptogenesis
1) Synaptic pre-patterning: Cell intrinsic processes that contribute to pre-establishment of synaptic components
2) Coordinated morphological and structural changes: Dendritic filopodia motility
3) Contact stabilization:Triggered by cell-to-cell ligand-receptor interactions and intra-cellular signaling cascades
4) Synaptic refinement: Activity-mediated strengthening or weakening of connections. Activity-mediated refinement of topography.
Alpha motor neurons receive input from 3 types of neurons. What are they?
Alpha motor neurons receive input from upper motor neurons, sensory input from muscle spindles and input from spinal interneurons
How does the myotactic (stretch reflex) work? Which neurons do the efferent neurons receive signals from?
The efferent alpha motor neurons receive signals from group 1a sensory neruons as well as interneurons
