Development of inhibitory synaptic transmission to the superior salivatory nucleus in rats
Development of inhibitory synaptic transmission to the superior salivatory nucleus in rats
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DOI：
10.1016/j.brainres.2007.11.020
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发表时间：
2008-01
期刊：
影响因子：
2.9
通讯作者：
Y. Mitoh;M. Funahashi;A. Fujii;M. Fujita;M. Kobashi;R. Matsuo
中科院分区：
文献类型：
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作者：
Y. Mitoh;M. Funahashi;A. Fujii;M. Fujita;M. Kobashi;R. Matsuo
大鼠颌下腺和舌下腺的初级副交感中枢是唾液上核，其神经元接受兴奋性(谷氨酸能)和抑制性(GABA能和甘氨酸能)突触传递。在本研究中，我们重点研究了新生大鼠从出生后第2天(P2)到第14天(P14)向SS神经元的抑制传递，以检验出生后神经发育。对脑干脑片上的神经元进行常规和穿孔性全细胞膜片钳技术。GABA能和甘氨酸能突触后电流的衰减时间常数由快成分(τFAST)和慢成分(τSlow)组成。PSC组件的τ快和τ慢都随着发展而变得更快。根据总−(GABA能+甘氨酸能)的翻转电势估算Cl-−的平衡电势。P8~P14组的ECL−明显高于P2~P7组的ECL−。外源性GABA作用于静息电位时，83%的SS神经元在P2-P7出现去极化，并伴随部分神经元的动作电位。相反，在P8-P14，GABA在78%的SS神经元上诱发超极化，因此，SS神经元直到P14才获得成熟的抑制系统。SS神经元的发育与参与口腔运动和感觉功能的外周唾液腺组织和脑干神经元的发育进行了比较。
The primary parasympathetic center of the submandibular and sublingual salivary glands is the superior salivatory (SS) nucleus, neurons of which receive excitatory (glutamatergic) and inhibitory (GABAergic and glycinergic) synaptic transmissions in rats. In the present study, to examine postnatal neural development, we focused on inhibitory transmission to the SS neurons in neonatal rats from postnatal day 2 (P2) to P14. Conventional and gramicidin-perforated whole-cell patch-clamp techniques were applied to the neurons in brainstem slices. The decay time constants of GABAergic and glycinergic postsynaptic currents (PSCs) consisted of fast (τfast) and slow (τslow) components. Both τfastand τslowof PSC components tended to become faster with development. The equilibrium potential of Cl−(ECl−) was estimated from the reversal potentials of total PSCs (GABAergic plus glycinergic). The ECl−in the P8–P14 group was significantly more negative than ECl−in the P2–P7 group. Exogenous GABA application at the resting potentials produced depolarization in 83% of SS neurons at P2–P7 and accompanied the action potential in some neurons. In contrast, at P8–P14, GABA evoked hyperpolarization in 78% of SS neurons; therefore, SS neurons did not acquire mature inhibitory systems until P14. The development of SS neurons is discussed as compared with the development of peripheral salivary gland tissue and brainstem neurons that participate in oral motor and sensory functions.