Contribution of nitric oxide to the depression of neuronal activity induced by temperature increase in the rat hippocampal CA1 area.
Using optical recording techniques, we examined whether nitric oxide (NO) is implicated in the impairment of the activity of hippocampal CA1 neurons induced by mild heat stress. A temperature increase from 32 to 38 degrees C reversibly depressed the neuronal activity in hippocampal slices. L-Arginine (1 mM), an NO donor, enhanced the heat-induced depression of the activity of hippocampal CA1 neurons. N(omega)-Nitro-L-arginine methyl ester, an inhibitor of nitric oxide synthase, attenuated the inhibition of the neuronal activity induced by a temperature increase. Methylcobalamin (10 microM), a vitamin B(12) analogue that reduces NO production, reduced the heat-induced depression of the neuronal activity. These results suggest that NO contributes, at least in part, to the heat-induced depression of the neuronal activity in the hippocampal CA1 region.
Takeya
Mitsue
M
Department of Physiology, Kurume University School of Medicine, 67 Asahi-machi, 830-0011, Kurume, Japan.
Hasuo
Hiroshi
H
Akasu
Takashi
T
D000818:Animals; D001120:Arginine / Q000494:pharmacology; D004558:Electric Stimulation; D004594:Electrophysiology; D006361:Heating; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D066298:In Vitro Techniques; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009474:Neurons / Q000502:physiology*; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D055095:Optics and Photonics; D051381:Rats; D017208:Rats, Wistar; D013696:Temperature; D014805:Vitamin B 12 / Q000031:analogs & derivatives* / Q000494:pharmacology
D020030:Nitric Oxide Donors; D009569:Nitric Oxide; D001120:Arginine; C019476:mecobalamin; D019001:Nitric Oxide Synthase; D014805:Vitamin B 12; D019331:NG-Nitroarginine Methyl Ester