3. Neurochemistry of sleep.
a. Basic concepts.
1. Noradrenalin (norepinephrine)
2. Serotonin (5HT)
3. Dopamine
a. Parachlorophenyalanine (PCPA) - prevents the neuronal manufacture of serotonin.
b. Alpha-methyl-para-tyrosine (AMPA) -inhibits synthesis of catecholamines NE and DA.
c. 6-hydroxydopamine - suppresses or destroys dopamine producing neurons.


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a. There are two types of insomnia:
1. One is due to a lack of serotonin with diminished synchronization of the EEG. Such periods of sleeplessness isn’t followed during subsequent secondary rebound states of SWS and PS.

2. The other is due to activation of ascending noradrenergic elements by stimulation of mesencephalic reticular formation noradrenergic cells. This is always followed by SWS and PS rebound that is proportional to duration of insomnia.

3. Both types of insomnia can be reversed to sedation by diminishing the turnover of catecholamines (administer alpha-amino-p-tyrosine).


b. There are two types of hypersomnia:

1. Active hypersomnia with accompanying SWS and PS which is due to the release of serotonin.

2. Prolonged cortical synchrony due to a disturbance of mesencephalic catecholamine producing neurons. There is no true increase of SWS and PS.