The dorsal raphe nucleus is the predominant source of central serotonin, where neuronal activity regulates complex emotional behaviors. Action potential firing of serotonin dorsal raphe neurons is driven via a1-adrenergic receptors (a1-A_R) activation. Despite this crucial role, the ion channels responsible for a1-A_R-mediated depolarization are unknown. Here, we show in mouse brain slices that a1-A_R-mediated excitatory synaptic transmission is mediated by the ionotropic glutamate receptor homolog cation channel, delta glutamate receptor 1 (GluD1). GluD1_R-channels are constitutively active under basal conditions carrying tonic inward current and synaptic activation of a1-A_Rs augments tonic GluD1_R-channel current. Further, loss of dorsal raphe GluD1_R-channels produces an anxiogenic phenotype. Thus, GluD1_R-channels are responsible for a1-A_R-dependent induction of persistent pacemaker-type firing of dorsal raphe neurons and regulate dorsal raphe-related behavior. Given the widespread distribution of these channels, ion channel function of GluD1_R as a regulator of neuronal excitability is proposed to be widespread in the nervous system.

中文翻译：

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Delta谷氨酸受体电导驱动小鼠背沟纹神经元的兴奋

背沟核是中央5-羟色胺的主要来源，其中神经元活动调节复杂的情绪行为。血清素背缝神经元的动作电位放电是通过a1-肾上腺素受体（a1-A _R）激活来驱动的。尽管这样至关重要的作用，负责A1-A的离子通道_[R介导的去极化是未知的。在这里，我们在小鼠脑切片中显示a1-A _R介导的兴奋性突触传递是由离子型谷氨酸受体同源阳离子通道，谷氨酸谷氨酸受体1（GluD1）介导的。GluD1 _R通道在基本条件下具有基本活性，携带进补电流和a1-A _R s的突触激活增强补剂GluD1 _R通道电流。此外，背缝GluD1 _R-通道的丧失产生焦虑症表型。因此，GluD1 _R通道负责a1-A _R依赖性诱导背脊神经元持续起搏器型放电并调节背脊相关行为。考虑到这些通道的广泛分布，建议在神经系统中广泛使用GluD1 _R的离子通道功能作为神经元兴奋性的调节剂。