1 / 65

Sleep II

Review. What is the biological clock?What is the best Zeitgeber?What is the retinohypothalamic tract?What gland produces melatonin?When are alpha waves produced?Describe stage 4 slow-wave sleep. When does it occur?What is paradoxical sleep, and when does it occur? . Brain areas that control s

helena
Download Presentation

Sleep II

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

    1. Sleep II

    2. Review What is the biological clock? What is the best Zeitgeber? What is the retinohypothalamic tract? What gland produces melatonin? When are alpha waves produced? Describe stage 4 slow-wave sleep. When does it occur? What is paradoxical sleep, and when does it occur?

    3. Brain areas that control sleep and waking

    4. Effects of brain lesions A cut at the base of the brain: Brain still shows normal rhythms of waking and sleeping. A cut through the midbrain: almost constant SWS sleep because it cuts off the reticular formation & locus coeruleus.

    5. Brain areas that control sleep and waking The basal forebrain (yellow) Part of it generates slow-wave sleep (SWS) via GABA. General anesthetics increase GABA activity. Another part increases wakefulness via acetylcholine The reticular formation (red) arouses the brain via glutamate & acetylcholine (also norepinephrine). The locus coeruleus (blue) arouses the brain via norepinephrine.

    6. Brain areas that control sleep and waking

    7. Brain areas that control sleep and waking A small area in the pons (yellow) triggers REM sleep via acetylcholine (ACh) to cortex & inhibits movement via GABA to spinal cord. Note: ACh increases cortical activity in both wakefulness and REM sleep. Raphe nuclei (parallel to retic. form., not shown in fig) produce serotonin. (complex role in sleep)

    8. Weird story of serotonin Lesions of raphe nuclei or serotonin antagonists ? insomnia. Therefore, necessary for sleep?? BUT, raphe neurons fire most rapidly during rhythmic activity, less during SWS, and are silent during REM. It may initiate a longer-term effect that later ? sleep. It also suppresses REM.

    9. Brain areas that control sleep and waking Hypothalamus Wake-promoting cells release histamine. Sleep promoting cells release GABA. Orexin-containing cells in lateral hypothalamus coordinate sleep, waking, and REM Narcolepsy results from loss of orexin neurons. No change in total sleep or wakefulness, but they are fragmented.

    10. Brain areas that control sleep and waking

    11. Summary Basal forebrain Acetylcholine (ACh) ? wakefulness GABA ? sleep Reticular formation Glutamate, ACh, norepinephrine ? wake Locus coeruleus Norepinephrine ? wake

    12. Summary Raphe nuclei Serotonin ? REM suppression (promote sleep indirectly?) Hypothalamus Histamine ? wakefulness GABA ? sleep Orexin ? transition among wake, SWS, REM

More Related