Sleep effects following intrathecal administration of the 5-HT1A agonist 8-OH-DPAT and the NMDA antagonist AP-5 in rats.
The modulating effect of an intrathecally (i.t.) administered 5-HT1A agonist and an NMDA antagonist on sleep, waking and EEG power spectra was investigated in rats. The 5-HT1A agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) (38 nmol) increased total slow wave sleep (TSWS) and decreased waking over the 8 h recording period. The TSWS increase was mostly due to an increase in SWS1. Sleep latency to SWS1 was also reduced. The NMDA antagonist dl-2-amino 5-phosphonovaleric acid (AP-5) (31.5 nmol) reduced waking. SWS1 was increased, but TSWS was not changed. An increase in REM sleep was seen during the last part of the recording. Combined treatment with 8-OH-DPAT and AP-5 reduced waking and increased TSWS. No change in REM sleep was seen. There were no systematic changes in either waking, TSWS or REM fronto-frontal or fronto-parietal EEG power spectrum after any of the treatments. The results suggest that in the spinal cord stimulation of 5-HT1A receptors have a dampening effect on transmission of sensory information, leading to deactivation and thereby increased possibilities for sleep induction. Blockade of the NMDA receptors may also lead to a small dampening of sensory transmission with similar consequences.
Bjørkum
A A
AA
Department of Physiology, University of Bergen, Norway.
Bjorvatn
B
B
Neckelmann
D
D
Ursin
R
R
D015763:2-Amino-5-phosphonovalerate / Q000008:administration & dosage / Q000494:pharmacology*; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D004347:Drug Interactions; D004569:Electroencephalography / Q000187:drug effects; D018691:Excitatory Amino Acid Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D007278:Injections, Spinal; D008297:Male; D009434:Neural Pathways / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors*; D017366:Serotonin Receptor Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D012890:Sleep / Q000187:drug effects*; D012895:Sleep, REM / Q000187:drug effects; D014851:Wakefulness / Q000502:physiology
D018691:Excitatory Amino Acid Antagonists; D016194:Receptors, N-Methyl-D-Aspartate; D017366:Serotonin Receptor Agonists; D015763:2-Amino-5-phosphonovalerate; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin