Role of adrenergic neuronal activity in the yawning induced by tacrine and NIK-247 in rats
The present experiments were performed to investigate the potential role of central adrenergic neurons in regulating occurrence of yawning in rats. Intraperitoneal injection of tacrine (THA) or 9-amino-2,3,5,6,7,8-hexahydro-1H-cyclopenta(b)-quinoline monohydrate HCl (NIK-247), cholinesterase inhibitors, induced yawning, which was markedly increased by pretreatment with the β-adrenoceptor antagonist, pindolol. The yawning evoked by tacrine or NIK-247 given alone or in combination with pindolol was inhibited by pretreatment with scopolamine but not by mecamylamine or spiperone. Treatment with tacrine or NIK-247 increased acetylcholine content of the striatum, but this effect was not enhanced by pindolol, which per se did not affect basal acetylcholine content. Moreover, pretreatment with the central adrenaline synthesis inhibitors, (+/-)-2,3-dichloro-α-methylbenzylamine HCl (LY-78335) and 2-cyclooctyl-2-hydroxyethylamine HCl (UK-1187A), increased tacrine-induced yawning. Subcutaneous injection of talipexole (B-HT 920), a dopamine D 2 receptor agonist, evoked yawning, which was also increased by pindolol, LY-78335, and UK-1187A. These receptors antagonists and synthesis inhibitors per se did not cause yawning responses. The results suggest that the β-adrenoceptor blockade and the inhibition of adrenaline synthesis facilitate the occurrence of yawning induced by cholinergic and dopaminergic agonists, and thus the central adrenergic neuronal systems may be implicated in the regulation of yawning responses.
원문보기 무료다운로드 유료다운로드
- 무료 원문 정보가 존재하지 않습니다.
NDSL에서는 해당 원문을 복사서비스하고 있습니다. 아래의 원문복사신청 또는 장바구니 담기를 통하여 원문복사서비스 이용이 가능합니다.