Posted: September 27th, 2022

Describe the meaning of each variable in the following equation

Q1
a) Describe the meaning of each variable in the following equation: I = gp(V – E) (/1)

b) How and why would an increase in equilibrium potential effect the current generated? (/0.5)
c) How are IPSPs created? What effect do they have on action potential generation (/0.5)
d) A pulse current of 30uA/cm^2 is applied to a neuron at rest, exceeding threshold
potential. Describe the steps in the generation of the action potential: how does this impact the membrane voltage, gating variables, and conductance? (/2)

e) What would happen if both the sodium and potassium ion channels opened simultaneously at the same speed? What could happen if this was accompanied by an influx of calcium? (/1)

Q2.
Cortical Columns
a) What do the basic functional units in cerebral processes represent? When are these units active? (/0.5)
b) Approximately how many neurons would you expect to have in a macro column? (/0.5)
c) Information processing: describe what is meant by “different columns respond to different stimuli” using Hubel and Wiesel’s experiment as an example. (/1)
d) What could potentially result from a GABAergic neural transmission blocker in terms of brain dynamics? (/0.5)
e) Describe the order of (thalamic) sensory information flow in a cortical column and the direction of inputs and outputs. (/2)
Q3.

The Visual/Striate Cortex:
) What are the different lobes of the cortex and locate one main functional area within each lobe? (/0.5)
c) How does visual information detected by the right eye travel through the brain to be processed? Outline the steps involved(/0.5)
d) How is visual information ordered during propagation in the visual pathway. How is it organized in the visual cortex? (/1.5)
e) A patient can describe a coffee mug that is in front of them, but they are having trouble reaching and grasping the mug. What viusal stream (dorsal or ventral) do you think this patient has damage in and why? Describe the area(s)/structure(s) in that stream which are likely also damaged. (/0.5)
f) Your friend thinks they have a concussion, they are curious about what brain structures would be impacted by their concussion and what the clinical consequences would be. Describe the cause of mild traumatic brain injury and resulting symptoms (/0.75)
Q4.
Subcortical structures
a) You want to increase the connective density of your hippocampus, outline a routine by which you could do so. (/0.25)
b) A connection between what two structures is essential in the formation of new memories? (/0.25)
c) A patient is unable to feel fear, even in life-threatening situations, which subcortical structure do you think is impaired? Describe the role of this structure. (/1.5)
d) Describe the type of experiments that revealed the role of this structure. Use an example. (/1.5)
e) What subcortical structure is most impacted in Parkinson’s disease and how? How does this explain some common motor symptoms? And what is the most common treatment? (/2)

Q5.
Mammalian Cortex:
) Explain the rationale behind the Brodmann subdivision of the cortex (/0.5)
a)
i. In which 3 layers of the brain would you find the soma of most pyramidal neurons? (/0.5)
ii. Name the inhibitory cell type extending across all cortical layers (/0.5)
iii. Which layer of the brain is the least densely populated with neuronal somata (/0.5)

b) What is the location of excitatory and inhibitory cortical neurons in the different cortical layers? (/1.5)

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