In recent years, considerable evidence is accumulated pointing to participation of gamma-aminobutyric acid (GABA) in intercellular signaling in the peripheral nervous system, including, in particular, neuromuscular transmission. However, where in the neuromuscular synapse GABA is synthesized remains not quite clear. We used histochemical methods to detect GABA and l -glutamate decarboxylase (GAD) in developing skeletal muscle fibers and in cultured motor neurons. We found that GABA can be detected already in myocytes, but with further muscle maturation, GABA synthesis gradually attenuates and completely ceases in early postnatal development. We found also that formation of GABA in muscle tissue does not depend on activity of GAD, but presumably proceeds through some other, alternative pathways. In motor neurons, GABA and GAD can be detected at the early stage of development (prior to synapse formation). Our data support the hypothesis that GABA and GAD, which are detectable in adult neuromuscular junctions, have neuronal origin. The mechanism of GABA production and its role in developing muscle tissue need further clarification.

中文翻译：

---

GABA 在大鼠骨骼肌和运动神经元发育中的作用

近年来，大量证据表明 γ-氨基丁酸 (GABA) 参与外周神经系统的细胞间信号传导，特别是神经肌肉传递。然而，GABA 在神经肌肉突触的何处合成仍不清楚。我们使用组织化学方法检测发育中的骨骼肌纤维和培养的运动神经元中的 GABA 和 l-谷氨酸脱羧酶 (GAD)。我们发现在肌细胞中已经可以检测到 GABA，但随着肌肉进一步成熟，GABA 合成逐渐减弱并在出生后早期发育完全停止。我们还发现肌肉组织中 GABA 的形成不依赖于 GAD 的活性，但可能是通过其他一些替代途径进行的。在运动神经元中，GABA 和 GAD 可以在发育的早期阶段（突触形成之前）检测到。我们的数据支持在成人神经肌肉接头中可检测到的 GABA 和 GAD 具有神经元起源的假设。GABA 的产生机制及其在肌肉组织发育中的作用需要进一步阐明。