Drug induced neuro-behavioural plasticity

Question 1

What neurons project to the nucleus accumbens?

Answer 1

Dopamine neurons from the VTA project to the NAc - involved in rewarding effects of drug, sex and food

Also receive excitatory transmission from glutamate - crucial for expression of reinfrocement learning

Question 2

What input does VTA receive?

Answer 2

Excitatory glutamate input from other brain areas (inc PFC)

Question 3

Define neuroplasticity

Answer 3

Structural and functional changes in neurons or synapses following experience

Question 4

What is non-contingent drug sensitization?

Answer 4

Increased behavioural response with repeated adminisistration (sensitization)

Long-lasting behavioural change

Question 5

What is contingent drug sensitization?

Answer 5

Associating certain behaviours with the drug

Called cue induced drug seeking

Creates very robust pattern of use

Question 6

What do dendritic spines tell us?

Answer 6

Spine head size correlates with AMPARs

Spine density correlates with connectivity (more spines = more input)

Question 7

How can we assess changes in neuronal morphology?

Answer 7

Golgi-Cox staining -

Question 8

What are the limitations of morphology analysis? (Robinson & Kold, 99)

Answer 8

We can observe structural changes but not functional ones

Some synapses could be silent

Question 9

What are neuronal ensembles?

Answer 9

Sparsely activated brain areas

Thought the ensembles in the NAc mediate learned associations between drug and administrtion environment