Lecture 4: The thalamus

Question 1

What is the function of the thalamus?

Answer 1

Master controller of input to the cortex - Ordering inputs and the level of input they have to the cortex.

Controls what becomes front of mind i.e stub toe and then bump into old friend, stubbed toe goes to back of mind etc.

Controls consciousness, when you stand up etc.

Question 2

Describe the organisation of the thalamic neurons:

Answer 2

The thalamic neurons are arranged to match the homunculus and discrete components of the thalamus deal with discrete functions

Question 3

What are the major thalamic groups of the nucleus?

Answer 3

Anterior nuclear group
Medial nuclear group
Lateral nuclear group
Intralaminar nuclear group
Metathalamus

Question 4

Whats the function of the anterior nuclear group of the thalamus?

Answer 4

Connects to the frontal cortex for memory and emotional processing

Sends info towards cortex and integrates info between limbic (FFF) and frontal regions(Reasoning).

Question 5

What is the function of the medial nuclear group?

Answer 5

Connects to the frontal and parietal association cortices for integration of sensory input

Question 6

What is the function of the lateral nuclear group?

Answer 6

Ventral part deals with motor planning (VA-VL) and sensory input (VPL and VPM nuclei) from the spinal cord but the lateral part does the same job as the medial nuclear group. (Homunculus representation)

Lateral group includes the pulvinar.

Question 7

What is the function of the intralaminar nuclear group?

Answer 7

Part of the reticular formation circuitry for conscious and regulation of the sensitivity of gravity opposing muscles

Question 8

What is the function of the metathalamus?

Answer 8

Comprised of the lateral and medial geniculate bodies for visual and auditory stimulus respectively.

Question 9

Does the thalamus receive olfactory inputs?

Answer 9

No

Question 10

Describe the internal capsule:

Answer 10

Like a funnel at the top of the spinal cord (bidirectional). The thalamus is acting as a relay. Lateral aspects of the thalamus will have fibres projecting into the internal capsule that remain close to the thalamus.

These fibres continue the homunculus representation.

Kink is known as genu

Question 11

Answer 11

Question 12

What thalamic nuclei project to these areas?

Answer 12

Question 13

Answer 13