PCL200H1 Chapter Notes - Chapter 7: Reticular Formation, Acetylcholine, Midbrain
Document Summary
Brain regions that determine arousal: reticular formation, thalamus, and cerebral cortex. Vigilance is correlated with the firing rate of neurons in the reticular formation. Reticular activating system (ras): sets arousal by releasing neurotransmitters norepinephrine and acetylcholine. When ras neurons are firing at high frequency, they release a lot of norepinephrine and acetylcholine into cortex, which creates state of high arousal. Midbrain is where histamine, dopamine, and norepinephrine neurons are located. Pons is location for neurons that produce acetylcholine and serotonin. When their activity is reduced, vigilance is reduced and a person becomes drowsy. The thalamus and hypothalamus are other important structures that determine wakefulness. One factor that contributes to cognition is attention - ability to focus on a given stimulus or idea and ignore other stimuli. Attention is directly correlated with arousal, and when arousal is low, attention is low.
