PSYC 211 Chapter Notes - Chapter 9.6: Encephalitis, Preoptic Area, Astrocyte
3 Jun 2016
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The degeneration of orexinergic neurons or the hereditary absence of orexin-b receptors causes narcolepsy. It has an excitatory effect on all these regions. Tmn, which activate the histaminergic neurons located there. Sleep is controlled by three factors- homeostatic, allostatic and circadian. The primary homeostatic factor that controls sleep is the presence or absence of adenosine. In some situations, it is important for us to stay awake: this control of sleep is allostatic in nature, a term that refers to reactions to stressful events in the environment and override homeostatic control. Allostatic control is mediated primarily by hormonal and neural responses to stressful situations and by neuropeptides. Circadian factors, or time of day factors, tend to restrict our period of sleep to a particular portion of the day and night cycle. When we are awake and alert, most of the neurons in our brain, especially those in the forebrain, are active, which enables us to perform a variety of cognitive functions.
