Sleep waking centres

The ultradian sleep—wake and temperature rhythm produced by 3rd ventricle infusion of TGFa closely resembles the effect of a focal excitotoxic lesion of SPZ neurons (Lu et al 2001). This ultradian rhythm is normally suppressed by circadian control and is disinhibited when SPZ neurons fail to relay SCN circadian information to sleep—wake circuits. Our results indicate that chronic TGFa administration uncouples SPZ neurons from sleep-regulatory circuits and that SPZ neurons expressing the EGFR transmit circadian information from the SCN to sleep—wake centres, in addition to likely regulating circadian locomotor activity. 

Figure 4. Llinas and Ribary (1993) identified in humans a synchronized gamma rhythm centred on 40 c/s during waking and sleep. In the two subjects (JV and ER), it was much more present during waking (A) and REM sleep (C) than during slow wave sleep (B, 6 sleep). D shows the noise of the system. Thirty-seven superimposed traces. Reprinted from Proceedings of National Academy of Science, with permission.

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