synaptic plasticity

Question 1

what is hebb (1949)’s description of learning

Answer 1

relatively permanent change resulting from experience ie repetition - at a synaptic level
when two synapses active at same time repetedly - connection becomes strengthened

Question 2

define habituation

Answer 2

weakened response to a stimulus as a result of repeated presentations

Question 3

describe eric kandell’s experiment for habituation

Answer 3

aphasia californica defensively withdraws sensitive body parts when exposed

Question 4

describe the results of habituation on neurons and muscles

Answer 4

before - sensory stimulates motor for withdrawal response
habituation - calcium channels become less responsive to stimulus in sensory neuron, less binds with calmodulin so less neurotransmitter released
less depolarisation at post synaptic

Question 5

define sensitisation

Answer 5

stronger response to repeated exposure to a stimulus

often novel or stranger than normal so causes a hyper response

Question 6

describe the results of sensitisation

Answer 6

interneuron releases serotonin onto metabotropic receptors on sensory pre,
potassium less responsive and reducing efflux of potassium and prolonging AP
prolonged AP means more calcium and increased neurotransmitter released
greater depolarisation

Question 7

Define long term potential ion

Answer 7

Persistent increase in synaptic strength
High freq stimulation between two active synaptaea
Most often in hippocampus - memory consolidation and learning

Question 8

What are the resultant pre and post synaptic changes due to LTP

Answer 8

Pre
Increased:
Axonal transport
Terminal size 
No synaptic vesicles
Density of contact zones 
Receptors
Protein transport for spine construction 
Size/area of spine 

Change size of synaptic cleft (closer if stronger)