Subcortical structures

What is the subcortex?

-Region beneath cortex
- Includes
Basal ganglia
• Diencephalon (Thalamus, subthalamus, hypothalamus) • Cerebellum

Why is the basal ganglia important?

Responsible for background movement & movement patterns
• a group of interconnected grey matter nuclei
• caudate nucleus• putamen• globus pallidus• substantia nigra• subthalamic nucleus• Amygdaloid body (Amygdala)

What is the caudate nucleus?

responsive to dopamine
involved with spatial and motor working memory (memory for movements and locations)
initiation of movement
frontal lobe executive function,
Involved in expressive language function,
attention, emotion regulation.

What are the Basal galglia structures?

Caudate Nucleus, Putamen, globus pallidus, Amygdala

What is the putamen responsible for?

works with other basal ganglia structures to control movement, learning new motor pattern

What is the globus pallidus do?

generating muscle tone

What does the amygdala do?

generation of fear and anxiety responses "Threat indicator", and a lesion to it can cause fearlessness (limbic system)

More structures

substantia nigra
Produce dopamine
utilized by basal ganglia (Caudate, putamen) to facilitate movement
Substantia nigra lesion
loss of neurotransmitter dopamine
results in hypokinesia: • Parkinson's disease

What happens when there is a Lesion of basal ganglia which results in a loss of GABA?

• GABA is the primary inhibitory neurotransmitter of CNS
• GABA inhibits substantia nigra, causing it to produce reduced
dopamine
• Dopamin is excitatory to putamen and caudate
• loss of GABA -\> more Dopamin-\> will result in hyperkinesia: Huntington's disease, tremor, dystonia..

What does the substantia nigra do?

- produces dopamine
- utilized by basal ganglia (Caudate, putamen) to facilitate movement

What happens when there is substantia nigra lesion?

- loss of neurotransmitters dopamine
-results in hypokinesia: Parkinson's disease

What is the diencephalon?

- intermediate processing center between cerebral cortex, basal ganglia, and cerebellum
-thalamus
-subthalamus
-hypothalamus

What is the thalamus?

- It is not a singular structure but a composite of different nuclei
- largest structures of deincephalon
-final relay for sensory info to cortex
-all sensations but olfaction pass through thalamus
- primary bridge for information from: cerebrum, globus pallidus (basal ganglia), motor cortex

What does the hypothalamus do?

- It regulates the reproductive behavior and physiology
-desire or perception of need for food and water
-perception of satiation, control of digestive processes, metabolism
-maintenance of water balance and body temperature

What happens when the hypothalamus is damaged?

-loss of appropriate autonomic responses - heart rate acceleration, sweating, shivering when cold
- moving to warmer environment when cold
- voracious eating or starvation/dehydration

What is the hippocampus?

- it is important in the development of spatial learning skills
- best known as a critical neural component for consolidating newly learned factual and event-related memories and transferring them into long-term storage
- it is considered a key experimental structure to examine the neurobiological (synaptic and molecular) foundations of learning and memory

Why is the cerebellum important?

- the primary structure responsible for coordination of fine movement
- It integrates somatic information, particularly related to vestibular function, muscle and joint sense, and perception of body in space
- It works with the cerebrum in fine-tuning the motor plan for optimal execution
- It is involved in monitoring and maintaining the background movement that supports fine motor control
- Structurally, the cerebellum has more neurons than the cerebrum!