Light induces cortical activation and yawning in rats.
We examined the effects of light stimulation on cortical activation and yawning response in anesthetized, spontaneously breathing rats. Cortical activation was assessed by means of an electrocorticogram (ECoG) and yawning response was evaluated by monitoring an intercostal electromyogram as an index of inspiratory activity and a digastric electromyogram as an indicator of mouth opening. Light stimulation elicited an arousal shift in the ECoG to faster rhythms. This arousal response was followed by a single large inspiration with mouth opening, i.e. a yawning response. Higher light intensity significantly reduced the onset latency of the arousal/yawning response. Pretreatment with pyrilamine, an H1-histamine receptor antagonist, injected into the lateral ventricle blocked both the cortical activation and the yawning response induced by light stimulation, suggesting a role of brain histaminergic neurotransmission in modulating the light-induced arousal/yawning responses.
Seki
Yoshinari
Y
Department of Physiology, Toho University School of Medicine, 5-21-16, Omori-nishi, Ota-ku, Tokyo 143-8540, Japan.
Nakatani
Yasushi
Y
Kita
Ichiro
I
Sato-Suzuki
Ikuko
I
Oguri
Mitsugu
M
Arita
Hideho
H
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D002540:Cerebral Cortex / Q000187:drug effects / Q000502:physiology*; D004569:Electroencephalography / Q000187:drug effects / Q000379:methods; D004576:Electromyography / Q000145:classification / Q000187:drug effects / Q000379:methods; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006634:Histamine H1 Antagonists / Q000494:pharmacology; D008027:Light; D008297:Male; D023421:Models, Animal; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D011738:Pyrilamine / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D013997:Time Factors; D015000:Yawning / Q000187:drug effects / Q000502:physiology*
D006634:Histamine H1 Antagonists; D011738:Pyrilamine