Neuro 6 - Thalamus and Hypothalamus

Question 1

What are the 3 areas of the diencephalon?

Answer 1

1. Thalamus
2. Subthalamus
3. Hypothalamus

Question 2

3 functions of the thalamus?

Answer 2

1. Relay centre to cortical sensory areas
2. Involved in most sensory systems (except olfactory)
3. Enhances / restricts signals

Question 3

Describe the somatosensory pathway

Answer 3

1. Proprioception goes into SC via DRG
2. Primary sensory neuron to medulla
3. Secondary sensory neuron to thalamus, where signal goes to ventral posterior lateral nucleus
4. From there, goes to primary somatosensory cortex

Question 4

What do the intralaminar nuclei do?

Answer 4

Project from thalamus onto medial temporal lobe structures

Question 5

What structures do intralaminar nuclei project onto?

Answer 5

Amygdala, basal ganglia, hippocampus

Question 6

What is the amygdala responsible for?

Answer 6

Emotions, fear, anxiety

Question 7

What is the basal ganglia responsible for?

Answer 7

Movement

Question 8

What is the hippocampus responsible for?

Answer 8

Memory

Question 9

What type of neurones largely composes the intralaminar nuclei?

Answer 9

Glutamatergic neurones (excitatory)

Question 10

Loss of intralaminar nuclei is associated with 2 conditions, what are they?

Answer 10

1. Parkinsons

2. Progressive supranuclear palsy

Question 11

What do the reticular nuclei do?

Answer 11

Forms outer covering of thalamus

1. Are largely GABAergic (i.e. inhibitory)
2. Connect with other thalamic nuclei - modulates thalamic activity

Question 12

What is reticular formation?

Answer 12

Interconnecting pathways of different neurones in the brainstem - sending ascending projections to forebrain nuclei

Question 13

What is ARAS

Answer 13

Ascending reticular activating system

These are the ascending projections from brainstem to forebrain nuclei

Question 14

What does increased ARAS activity mean?

Answer 14

Increased wakefulness/consciousness

Question 15

Intralaminar and reticular nucleic receive inputs from?

Answer 15

ARAS

Question 16

What structure divides the hypothalamus into two?

Answer 16

3rd ventricle

Question 17

The hypothalamus consists of individual nuclei with distinct functions. How are the nuclei connected?

Answer 17

Ipsilateral connections with other nuclei

Question 18

What are the functions of the hypothalamus?

Answer 18

1. Directly connects to ANS
2. Connects to endocrine systems
3. Control of behaviour

Question 19

Paraventricular nucleus contains to types of neurones, which are?

Answer 19

Parvocellular and magnocellular

Question 20

What type of PVN neurone synapses to SC?

Answer 20

Parvocellular

Question 21

Where do the magnocellular neurones project?

Answer 21

PPG

Question 22

Inhibiting the PVN causes increases feeding

Answer 22

T

Question 23

What is the suprachiasmatic nucleus responsible for?

Answer 23

Sleep/wake cycle - controlled by light.

Influences pineal gland which releases melotonin