Short and Long Term Plasticity Flashcards
Plasticity: changes in _____ function as a result of _____
Neuronal
Experience
What does “experience” refer to in terms of plasticity?
Prior excitation or inhibition
Plasticity enables the _____ to change the _____.
Environment
Neuron
Plasticity always requires _____ signaling.
Intracellular
Plasticity can last from _____ to ____ and ____ (time frame).
mSec
Hours and days
Plasticity can change neurons in what 4 ways?
- Excitability of neuron (ability to fire action potential)
- Ability of neuron to signal to another neuron
- Number and type of synapses on a neuron
- How many other neurons it synapses with
Plasticity underlies ____ and ____ at both the cellular and organismal level.
Learning
Memory
Of the methods of synaptic strength modulation, which 4 are considered short term? Which one has the shortest time frame?
Facilitation Depression Augmentation Potentiation Shortest time frame: facilitation
Synaptic strength is related to what?.
Amplitude of depolarization
Facilitation: increase or decrease synaptic strength, time scale
Increase
mSec
Depression: increase or decrease synaptic strength, time scale
Decrease
mSec-seconds
Augmentation: increase or decrease synaptic strength, time scale
Increase
Seconds
Potentiation: increase or decrease synaptic strength, time scale
Increase
Minutes
Habituation: increase or decrease synaptic strength, time scale
Decrease
Minutes
Sensitization: increase or decrease synaptic strength, time scale
Increase
Minutes-hours
Long-term depression: increase or decrease synaptic strength, time scale
Decrease
Hours-days
Long-term potentiation: increase or decrease synaptic strength, time scale
Increase
Hours-days
As a general rule, the longer the time scale of modulation, the more ____ and greater _____ of mechanisms underlie it.
Complex
Number
Many of the long-term mechanisms of synaptic modulation proceed through ___-____ pathways first.
Short-term
In facilitation, what difference would you see in membrane potential (Vm) between the pre- and post-synaptic neuron? What is happening on the pre-synaptic side that causes this phenomenon?
Post-synaptic neuron has an increase in Vm
Greater vesicle release on the pre-synaptic side
Facilitation is due to the fact that after an action potential, clearing of ____ (ion) from the pre-synaptic side is relatively ____ (speed).
Ca+2
Slow
In facilitation, if the interval between action potentials is short and the Ca+2 from the previous action potential has not been cleared, what is the effect on Ca+2 concentration and synaptic vesicle release?
Ca+2 concentration increases
More synaptic vesicles are released
Facilitation has a direct relationship with what action potential-related phenomenon? What about this relationship yields the short time frame under which facilitation occurs?
Minimum interspike interval (minimum interval between action potentials)
Minimum interspike interval is short, so facilitation is short
Depression causes an (increase/decrease) in post-synaptic membrane potential at high stimulation. Why?
Decrease
Pool of vesicles is depleted, so ability of pre-synaptic cell to cause depolarization is decreased
Of depression and augmentation, which is seen at normal pre-synaptic Ca+2 levels? Which is seen at low pre-synaptic Ca+2 levels?
Depression
Augmentation
Augmentation causes an (increase/decrease) in post-synaptic membrane potential at high stimulation. What causes this, and what about pre-synaptic Ca+2 levels makes this effect visible?
Increase
High stimulation causes more vesicles to be released
Low pre-synaptic Ca+2 levels slows down molecular machinery, so effect of increased vesicle fusing is seen
Potentiation is observed under (lower/higher) pre-synaptic stimulation than in the depression experiments.
Lower
In potentiation, increase in intracellular ____ (ion) activates _____ that ______ proteins involved in ____ release. What effect does this have on the proteins, and thus post-synaptic membrane potential?
Ca+2 Kinases Phosphorylate Vesicle Increases activity of proteins Increases membrane potential
The model organism Aplysia is what type of animal?
Sea slug
Aplysia has 2 sensory neurons, one at the _____ skin and one at the ____. What neurotransmitter do these sensory neurons release?
Siphon
Tail
Glutamate
The siphon skin sensory neuron of Aplysia synapses onto a ____ neuron that is attached to the ____. What neurotransmitter does the latter neuron release?
Motor
Gill
Acetylcholine
Poking the siphon of Aplysia causes its ____ neuron to release _____, which activates ____ release by the ____ neuron that triggers gill _____.
Sensory Glutamate Acetylcholine Motor Retraction
The tail sensory neuron of Aplysia synapses onto a ___ ___, which releases ____ (neurotransmitter) onto the ___ neuron of the ____, which changes its ability to release ____.
Modulatory interneuron Serotonin Sensory Siphon Glutamate
In Aplysia, touching the siphon causes an action potential in the ____ neuron, which triggers an excitatory post-synaptic potential in the ____ neuron, which causes ____ contraction.
Sensory
Motor
Gill
Habituation in Aplysia: repeated touching of the siphon causes a ____ in motor neuron excitatory post-synaptic potential, leading to ____ contraction of the gill.
Decrease
Lessened
Sensitization in Aplysia: what is done to the tail before touching the siphon? What effect does this have on motor neuron post-synaptic potential and gill contraction?
Tail is shocked
Increases motor neuron post-synaptic potential and magnitude of gill contraction
In habituation, repeated stimulation of the same pathway leads to ____ response.
Lessened
Of habituation and sensitization, which is considered to be multi-trial circuit learning and which is considered to be single trial learning? Why?
Habituation- multi-trial circuit learning (effect only seen after multiple stimulations)
Sensitization- single trial learning (effect seen after only 1 stimulation)
In Aplysia habituation, which is lessened with repeated stimulation, the action potential of the sensory neuron or the action potential of the motor neuron? What is happening at the neurotransmitter level that causes that change?
Action potential of motor neuron
Sensory neuron is releasing less glutamate onto motor neuron, so excitation isn’t as strong
In Aplysia sensitization, shocking the tail causes the sensory neuron to release what? Modulatory interneuron to release what? How does this effect the siphon sensory neuron’s ability to release its neurotransmitter upon stimulation through poking? What effect does this then have on the motor neuron?
Shocking tail -> glutamate release by tail sensory neuron -> serotonin release by modulatory interneuron -> increased glutamate release by siphon sensory neuron
Increased glutamate release means increased excitation of motor neuron, so stronger gill withdrawal
In Aplysia sensitization, release of serotonin on the siphon sensory neuron activates what type of serotonin GPCR (Gs, Gi, or Gq) on the (siphon sensory neuron/modulatory interneuron)?
Gs
Siphon sensory neuron
Aplysia sensitization: Activation of serotonin Gs coupled GPCR in the siphon sensory neuron stimulates _____ to make ____, which activates ____ ____ ___.
Adenylyl cyclase
cAMP
Protein kinase A