Neuronal mechanisms involved in yawning behavior: Role of <alpha> -melanocyte-stimulating hormone.

一项行为学研究试图了解与大鼠打哈欠行为有关的神经机制。皮下注射低剂量阿波啡、匹瑞贝地尔、3-PPP和TL-99诱发哈欠。SK&F-38393是一种多巴胺D-1受体激动剂，既不会引起打哈欠，也不会引起刻板印象。但是溴隐亭，一种多巴胺D-2受体激动剂，诱导打哈欠，其剂量-反应曲线呈钟形。经多巴胺D-2受体拮抗剂舒必利治疗后，全身注射阿波啡、匹瑞贝地尔、3-PPP或溴隐亭引起的哈欠反应完全被抑制。另一方面，阿帕吗啡诱导的打哈欠被多普萘洛尔和品多洛尔增加，而哌唑嗪没有引起打哈欠。SK&F-38393联合< β > -肾上腺素受体拮抗剂不诱导打哈欠。阿波啡或匹利贝地尔联用品多洛尔引起的哈欠可被spiperone、多巴胺D-2受体拮抗剂和东莨菪碱抑制，而多巴胺D-1受体拮抗剂SCH-23390则无抑制作用。品多洛尔对毒豆碱和匹罗卡品诱导的哈欠也有增强作用，东莨菪碱对增强的哈欠有抑制作用，而spiperone、sm -09151-2和SCH-23390对增强的哈欠没有抑制作用。双侧向纹状体或隔膜注射阿波啡、匹瑞贝地尔或3-PPP也会引起明显的打哈欠。新生期注射谷氨酸单钠阿波啡致成年大鼠打哈欠。此外，脑室内注射< α - > -促黑素抗血清不能抑制阿吗啡诱导的哈欠。结果表明，多巴胺能激动剂诱导的哈欠是由多巴胺D-2受体介导的，而不是由< α > -黑素能系统介导的。< β > -肾上腺素能受体阻断对打哈欠的发生有刺激作用，纹状体和间隔多巴胺能系统也可能与打哈欠行为的发生有关。少

A behavioral study was performed in an attempt to understand the neuronal mechanisms involved in yawning behavior in rats. Subcutaneous injections of low doses of apomorphine, piribedil, 3-PPP and TL-99 evoked yawning. SK&F-38393, a dopamine D-1 receptor agonist, induced neither yawning nor stereotypy. But bromocriptine, a dopamine D-2 receptor agonist, induced yawning for which the dose-response curves showed a bellshaped form. Yawning responses induced by systemic injection of apomorphine, piribedil, 3-PPP or bromocriptine were wholly suppressed after the treatment with sulpiride, a dopamine D-2 receptor antagonist. On the other hand, the apomorphine-induced yawning was increased by dl-propranolol and pindolol which did not induce yawning but not by prazosin. SK&F-38393 in combination with <beta> -adrenoceptor antagonists did not induce yawning. The yawning elicited by apomorphine or piribedil in combination with pindolol was suppressed by spiperone and YM-09151-2, dopamine D-2 recep … More tor antagonists, and scopolamine, a muscarinic receptor antagonist, but not by SCH-23390, a dopamine D-1 receptor antagonist. Pindolol also enhanced the yawning induced by physostigmine and pilocarpine, and the enhanced yawning was inhibited by scopolamine but not by spiperone, YM-09151-2 and SCH-23390. Bilateral injections of apomorphine, piribedil or 3-PPP into the striatum or septum also elicited a marked yawning. Apomorphine induced yawning in adult rats which had been injected during the neonatal period with monosodium glutamate. Moreover, apomorphine-induced yawning was not inhibited by an intraventricular injection of antiserum of <alpha> -melanotropin. The results indicate that the yawning induced by dopaminergic agonists is mediated by dopamine D-2 receptors but not by <alpha> -melanotropinergic systems. <beta> -Adrenoceptor blockade exerts a stimulatory effect in the occurrence of yawning and striatal and septal dopaminergic systems may be also related to the occurrence of yawning behavior. Less