Lecture 9.1-9.2: Emotion

Question 1

Limbic loop

Answer 1

The ventral striatum/nucleus accumbens receives excitatory cortical input (from the amygdala, hippocampus, orbitofrontal, anterior cingulate, temporal cortex) as well as dopaminergic input from the VTA (causing synaptic potentiation).

The nucleus accumbens has an inhibitory effect on the ventral pallidum, substantia nigra and pars reticulata.

Those inhibited regions then can’t inhibit the mediodorsal nucleus of the thalamus, which is then free to excite the limbic cortex.

Question 2

What is the source of dopamine to the prefrontal cortex and associated basal ganglia regions?

Answer 2

The ventral tegmental area (VTA) is a source (via the median forebrain bundle) of dopamine to prefrontal cortex and associated basal ganglia regions.

Question 3

Mechanism of opiates

Answer 3

Decrease activity of inhibitory GABAergic VTA interneurons and also directly on the nucleus accumbens

Question 4

The source/principle site for synthesis of noradrenaline

Answer 4

The locus coeruleus is the principal site for brain synthesis of norepinephrine (noradrenaline)

Question 5

Principal source of serotonin

Answer 5

Raphe nuclei of the brain stem

Question 6

True or false:

Dopamine depletion eliminates behaviours associated with pleasurable or aversive experiences.

Answer 6

False, dopamine is associated with the anticipation of reward, but does not eliminate pleasurable behaviour.

Question 7

The fibres of the VTA and substantia nigra travel in the

Answer 7

median forebrain bundle

Question 8

The two main projections of the VTA

Answer 8

1) the meso-limbic projection to the “limbic cortex” (nucelus accumbens and anterior temporal regions)
2) the meso-cortical projection which is concentrated on the prefrontal cortex.

Question 9

Ventral pallidum neurons normally _____ the thalamus

Answer 9

inhibit

Question 10

striatal neurons have a ____ effect on the neurons in the ventral pallidum

Answer 10

inhibitory