Systems Neuro Final

How does optogenetics stimulate neurons?

Opsins are a protein that are light sensitive and function as light gated ion channels, causing an influx in Na+ leading to Action Potentials when exposed to light

What are two motor brain regions related to saccadic eye movements

Superior colliculus - takes in visual information (how it is moving, where it is) to make a motor plan and create a saccade to contralateral side

Striatum of the basal ganglia - disinhibits the superior colliculus by inhibiting SNr, helps to activate the saccade

What type of eye movement is used for steadily tracking something

Smooth pursuit eye movement

How do you make an eye saccade to the left

Left PPRF (gaze center) will excite the left lateral rectus directly and the right oculomotor nucleus, which will the excite the contralateral right medial rectus.

If I want an enjoyable experience eating spicy food, what is the brain area involved

Hypothalamus - regulates response to the casaicin

What is the difference between the 1st and 2nd generation drugs to treat psychosis

1st gen: selectively an aganost to D2 (dopamine receptors) which inhibits positive symptoms of psychosis such as hallucinations

2nd gen: an aganost to D2 (dopamine receptors) and serotonin, minimizes adverse effects that worsen negative symptoms

OFC Function

Attaches value to an object of interest (reward/punishment)

PFC Function

Creates rules and context to apply the values of objects to

ACC Function

Signals conflict to adjust decisions adaptively when rules are broken

Why are retina waves important for the development of V1

retina waves are waves of APs that fire for retinal cells that are physically near each other. This establishes a retinotopic map that creates spatial maps through experience-dependent learning?LTP

Explain the Central Pattern Generator diagram

For each muscle involved, there should be one neuron: that neuron will excite its muscle and inhibit any of the other muscles involved in the circuit, and each neuron should excite each other in a cyclic pattern to continue the pattern

In the developing organism, how would the neuron know to project to muscle A and not muscle B

Chemoattractants from A and chemorepulsions from B

Broca’s aphasia

Language disorder that disrupts the prefrontal region of language that is involved in language production. Comprehension is intact, but disordered grammar & syntax (grammatical structures & rules of language)

Wernicke’s aphasia

Disrupts that “What” pathway of language. Can’t comprehend language but produces language with adequate syntax/grammar

What property of light waves determine color

wavelength

What is the role of the optic chiasm

Relays visual information contralaterally (Right visual field to left side of brain, left visual field to right side of brain)

What type of photoreceptor is responsible for scotopic vision (low light vision)

Rods

Are photoreceptors more active in the presence or absence of light

Absence

How does visual sensory info travel through the brain

APs begin with the retinol ganglion cells → travel down the optic nerve until they hit the optic chiasm → Causes the right side of the left retina and left side of the right retina to cross over (so that all right visual field is in the left and vice versa) → signals travel to the thalamus → sent to the striate cortex

Dorsal vs ventral pathway

Dorsal = parietal lobe, in charge of spatial vision (where)

Ventral = temporal lobe, in charge of object recognition (what)

Why is it important that photoreceptors don’t fire action potentials

Photoreceptor cells need to be highly sensitive to light/color to detect stimuli, and generating APs require a higher threshold of stimulation which reduces sensitivity. Also saves energy, as vision is constant

What part of the basilar membrane do low frequency waves stimulate, and why?

The apex, which is at the wider end of the basilar membrane in the cochlea - the basilar membrane is like a cone, so low frequency waves that are wider can resonate longer and travel further down the basilar membrane

What part of the ear allows sound waves to be converted to nerve signals interpretable by the brain

inner hair cells