Task3 - Consolidation, Plasticity And LTP

Question 1

Neuromodulator

Answer 1

Acts to modulate activity in whole brain rather than one synapse

Question 2

Synaptic plasticity

Answer 2

Ability of synapse to change as a result of experience

Question 3

He Ian learning

Answer 3

Principle that learning involves strengthening the connections of coactive neurons = neurons fire together wire together

Repeated exposure to stimulus -> strengthens connections within subset of neurons -> subset provides increasingly reliable basis for identifying the stimulus that is activating them

Question 4

Long term potentiation (LTP)

Answer 4

Process in which synaptic transmission becomes more effective as a result of recent activity

Changes can last for hours or days

Question 5

Long term depression (LTD)

Answer 5

Process in which synaptic transmission becomes less effective as a result of recent activity

Question 6

What changes in LTP

Answer 6

1. Postsynaptic neurons change to become more responsive -> heightened sensitivity to neurotransmitter
2. May lead to changes to presynaptic neurons (but not clear how signals could travel backward across synapse

Question 7

Changes in synapse to form and store memories

Answer 7

1. changes involving synaptic transmitters: more transmitter release, less transmitter when postsynapse is more sensitive, more transmitter with larger pre and postsynapse
2. Interneuron modulation -> increased transmitter release
3. Formation of new synapses
4. rearrangement of synaptic input -> more frequently used neural pathway takes over synaptic sites formerly occupied by less active competitor

Question 8

Informal learning opportunities (experiment with isolated and enriched conditions rates)

Answer 8

Enriched conditions lead to development of greater activity of enzyme acetylcholine in cerebral cortex

Question 9

Early stage LTP

Answer 9

1. Glutamate is released -> activates only AMPA receptors (NMDA receptors do not respond because magnesium blocks the receptor
2. Sufficient activation of AMPA receptors can partially depolarize the membrane -> removes magnesium
3. NMDA receptors respond actively to glutamate and let larger amounts of CA2+ in
4. Large influx of CA2+
5. CA2+ activates calmodium which activates CaMK
6. CaMK phosphorilates AMPA receptors and promotes the movement of AMPA receptors from the interior of the spine into the membrane

Question 10

Late LTP

Answer 10

1. Strong stimulation -> increased concentration of CA2+
2. Activation of kinases (calmodium, CaMK, PKA, PKC) which phosphrylate proteins
3. Activated kinases bind to CREB -> production of mRNA of immediate early genes
4. Many immediate early genes code for transcription factors -> proteins enter nucleus and regulate the expression of particular late effector genes
5. Transcription of LEGs leads to synthesis of proteins, including enzymes and structural proteins. Some of these proteins are necessary to induce LTP
6. Many of the synthesized proteins are transported down the axon into dendritic to alter the response of the neuron to further stimuli