Arousal Systems

Question 1

• Reticular Formation

Answer 1

n = “Net” from Medulla & Pons > throughout Forebrain;

Also receives from all sensory systems

• Alerts brain, stimulating Thalamus and Basal Forebrain (and from there, cortex) via ACh and Glutamate

Question 2

Locus Coeruleus

esp active during…?

Answer 2

(=“Dark Blue Place”) Part of Reticular Formation in Pons,

• Especially active during new task & during vigilance;

Can also be inactive while awake

Question 3

Locus Coeruleus, releases

Answer 3

bursts of Norepinepherine (NE) - Amphetamines (NE-agonists) likewise increase alertness, activity

Question 4

Locus Coeruleus, Widespread connections, including

Answer 4

Thalamus, Cortex, & Hippocampus - plays a role in establishing memory

Question 5

Basal Forebrain

where?

releases?

Answer 5

(just anterior and dorsal to Hypothalamus) releases ACh thruout cortex for arousal & GABA to inhibit cortex

Question 6

Damage to Basal Forebrain implicated in

Answer 6

Alzheimer’s Disease; arousal critical to memory activation

Question 7

Adenosine

Answer 7

a by-product of cell metabolism,

builds up thru day, released in brain, inhibits Basal Forebrain’s release of ACh

• Allows GABA connections to dominate, suppressing cortical activity, promotes sleep

Question 8

Caffeine

Answer 8

blocks Adenosine receptors, allowing Basal Forebrain to continue to arouse brain

Question 9

Basal Forebrain also selectively modulates….

Answer 9

…hindbrain activity ; Possible source of Pons’ initiation of PGO wave?

Question 10

Adenosine

Answer 10

a by-product of cell metabolism,

builds up thru day,

released in brain,

inhibits Basal Forebrain’s release of ACh