Limbic/Basal Ganglia Info

Question 1

What structures are involved/included in the limbic system? (6)

Answer 1

Hippocampus
Amygdalae
Mammillary bodies
Anterior Thalamic nuclei
Cingulate gyrus
Entorhinal cortex

Question 2

What is the Limbic system involved in? (5)

Answer 2

Emotion, Long term memory, olfaction, behavior modulation, ANS function
5 F’s (fleeing, Feeding, Fighting, Feeling, Fucking)

Question 3

Alterations in this pathway would be caused by/ cause what?

Mesocortical pathway

Answer 3

Decreased activity
Negative symptoms of Psychosis
(Anergia, Apathy, lack of spontaneity)
(antipsychotic drugs have limited effect)

Question 4

Alterations in this pathway would be caused by/ cause what?

Mesolimbic pathway

Answer 4

Increased activity
Positive symptoms of psychosis
(delusions, hallucinations)
(primary target of antipsychotics)

Question 5

Alterations in this pathway would be caused by/ cause what?

Nigrostriatal pathway

Answer 5

Decreased activity
Extrapyramidal symptoms
(dystonia, akathisia, parkinsonism, tardive dyskinesia)
(Major dopa pathway in brain, significantly affected by movement disorders and antipsychotic drugs)

Question 6

Alterations in this pathway would be caused by/ cause what?

Tuberoinfundibular pathway

Answer 6

Decreased activity

Increases prolactin which decreases libido sexual dysfunction, galactorrhea, gynecomastia (in men)

Question 7

What is the role of the basal ganglia?

Answer 7

Important in voluntary movements and making postural adjustments

Receives cortical input, provides negative feedback to cortex to modulate movement

Question 8

What structures are involved in the basal ganglia?

Answer 8

Striatum= putamen (motor) + caudate (cognitive)
Lentiform= putamen + globus pallidus

Question 9

Describe the Direct pathway of the basal ganglia

Answer 9

Excitatory pathway:
SNc input stimulates the striatum stimulating it to release GABA –> that inhibits GABA release from the Globus Pallidus internus disinhibiting the thalamus (via inhibition of GPi’s inhibition)
(dec motion)

Question 10

Describe the indirect pathway of the basal ganglia

Answer 10

Inhibitory pathway
SNc input stimulates the striatum, releasing GABA that disinhibits STN via GPe inhibition, and STN stimulates GPi to inhibit the thalamus
(INC motion)

Question 11

What effect do D2 receptors have on the basal ganglia

Answer 11

D2 receptors act via the indirect pathway to inhibit movement

Question 12

What effect do D1 receptors have on the basal ganglia

Answer 12

D1 (D1rect) act by the direct pathway to facilitate movement