MCB 461 FINAL EXAM | 111 QUESTIONS | WITH PASSED SOLUTIONS!!
How does binocular vision develop before birth? - (answer)Thalamic inputs representing
the left and right eyes segregate from each other to form "ocular dominance" columns
of roughly equal width in the visual cortex
How does binocular vision develop soon after birth? - (answer)During the critical period,
the visual experience shapes and combines the representations of the 2 eyes in the
cortex to make binocular vision possible
Normal binocular vision consolidates and refines the established patterns of ocular
representation
Depends on correlated patterns of activity from 2 eyes and convergence of inputs from
Layer IV to III
What happens if you perform monocular deprivation during the critical period? -
(answer)The LGN axons from the deprived eye in layer 4 will shrink and decrease in
synaptic strength, whereas axons from the non-deprived eye expand and increase in
synaptic strength
What happens if you reinstate normal vision during monocular deprivatioN? -
(answer)This does not readily restore normal binocular responses in the cortex.
The non deprived eye continues to dominate the responses of cortical neurons (even up
to 5 years)
A critical period of binocular vision - (answer)A "critical period" to establish binocular
receptor fields
Effects of disruptions of binocular vision are IRREVERSIBLE when they occur in the
critical period. In cats, this begins rapidly at 3 weeks. After 6 weeks, this period gradually
closes.
,MCB 461 FINAL EXAM | 111 QUESTIONS | WITH PASSED SOLUTIONS!!
What are some mechanisms of binocular plasticity? - (answer)Modulation of LGN axons
that project to layer 4
Adjust synaptic drive by the left and right eyes (NMDA receptor activation)
Mechanisms that contribute to synapse formation or stabilization (BDNF,
neuromodulators—acetylcholine, norepinephrine)
PirB or Nogo and its receptors
Precise balance between excitatory and inhibitory inputs
Critical period is delayed in GABAA receptor knock out mice
Dark rearing prolongs the critical period
Hebbian plasticity - (answer)Persistent activation of a group of simultaneously active
neurons would lead to consolidation of stronger connection
In response to extrinsic stimuli, neurons can change and adapt the strength of their
connections. Examples are long term potentiation (LTP) and long term depression (LTD)
Hebbian Plasticity is - (answer)Associative
Rapidly induced
Input specific
Positive feedback process
Physiological relevance
Cellular correlate of "learning and memory"
Where does Hebbian synaptic plasticity happen? - (answer)The HIPPOCAMPUS
LTP and LTD are key to forming declarative memories in the brain
, MCB 461 FINAL EXAM | 111 QUESTIONS | WITH PASSED SOLUTIONS!!
Pathway from entorhinal cortex - (answer)Goes from pyramidal cells in the dentate
gyrus to pyramidal cells in CA3 to pyramidal cells in CA1
Synaptic plasticity in the hippocampus is the key to forming - (answer)Declarative
memories in the brain
LTP happens at glutamatergic synapses in hippocampus: discovered by - (answer)Bliss
and Lomo
Dark circles: POTENTIATED, and their amplitude is higher
In the hippocampus, the EPSP magnitude __________during LTP - (answer)Increases
In the hippocampus, the EPSP magnitude _____________ during LTD - (answer)Decreases
What's the problem with Hebbian platicity - (answer)Eventually, persistently activating
neuronal networks would reach an extreme and become unstable
Homeostatic plasticity - (answer)Rapid or prolonged process to maintain neuronal firing
and synaptic strength *within physiological limit*, thereby preventing un-restrained
increases or decreases in neuronal activity
How does homeostatic plasticity work - (answer)Induced rapidly or in a long term
Global but unequal scaling
Homeostatic negative feedback process
How does binocular vision develop before birth? - (answer)Thalamic inputs representing
the left and right eyes segregate from each other to form "ocular dominance" columns
of roughly equal width in the visual cortex
How does binocular vision develop soon after birth? - (answer)During the critical period,
the visual experience shapes and combines the representations of the 2 eyes in the
cortex to make binocular vision possible
Normal binocular vision consolidates and refines the established patterns of ocular
representation
Depends on correlated patterns of activity from 2 eyes and convergence of inputs from
Layer IV to III
What happens if you perform monocular deprivation during the critical period? -
(answer)The LGN axons from the deprived eye in layer 4 will shrink and decrease in
synaptic strength, whereas axons from the non-deprived eye expand and increase in
synaptic strength
What happens if you reinstate normal vision during monocular deprivatioN? -
(answer)This does not readily restore normal binocular responses in the cortex.
The non deprived eye continues to dominate the responses of cortical neurons (even up
to 5 years)
A critical period of binocular vision - (answer)A "critical period" to establish binocular
receptor fields
Effects of disruptions of binocular vision are IRREVERSIBLE when they occur in the
critical period. In cats, this begins rapidly at 3 weeks. After 6 weeks, this period gradually
closes.
,MCB 461 FINAL EXAM | 111 QUESTIONS | WITH PASSED SOLUTIONS!!
What are some mechanisms of binocular plasticity? - (answer)Modulation of LGN axons
that project to layer 4
Adjust synaptic drive by the left and right eyes (NMDA receptor activation)
Mechanisms that contribute to synapse formation or stabilization (BDNF,
neuromodulators—acetylcholine, norepinephrine)
PirB or Nogo and its receptors
Precise balance between excitatory and inhibitory inputs
Critical period is delayed in GABAA receptor knock out mice
Dark rearing prolongs the critical period
Hebbian plasticity - (answer)Persistent activation of a group of simultaneously active
neurons would lead to consolidation of stronger connection
In response to extrinsic stimuli, neurons can change and adapt the strength of their
connections. Examples are long term potentiation (LTP) and long term depression (LTD)
Hebbian Plasticity is - (answer)Associative
Rapidly induced
Input specific
Positive feedback process
Physiological relevance
Cellular correlate of "learning and memory"
Where does Hebbian synaptic plasticity happen? - (answer)The HIPPOCAMPUS
LTP and LTD are key to forming declarative memories in the brain
, MCB 461 FINAL EXAM | 111 QUESTIONS | WITH PASSED SOLUTIONS!!
Pathway from entorhinal cortex - (answer)Goes from pyramidal cells in the dentate
gyrus to pyramidal cells in CA3 to pyramidal cells in CA1
Synaptic plasticity in the hippocampus is the key to forming - (answer)Declarative
memories in the brain
LTP happens at glutamatergic synapses in hippocampus: discovered by - (answer)Bliss
and Lomo
Dark circles: POTENTIATED, and their amplitude is higher
In the hippocampus, the EPSP magnitude __________during LTP - (answer)Increases
In the hippocampus, the EPSP magnitude _____________ during LTD - (answer)Decreases
What's the problem with Hebbian platicity - (answer)Eventually, persistently activating
neuronal networks would reach an extreme and become unstable
Homeostatic plasticity - (answer)Rapid or prolonged process to maintain neuronal firing
and synaptic strength *within physiological limit*, thereby preventing un-restrained
increases or decreases in neuronal activity
How does homeostatic plasticity work - (answer)Induced rapidly or in a long term
Global but unequal scaling
Homeostatic negative feedback process
