Arata A, Onimaru H, Homma I
Department of Physiology, Showa University School of Medicine, Japan.
Brain Res Bull. 1990 Apr;24(4):599-604. doi: 10.1016/0361-9230(90)90165-v.
In brainstem-spinal cord preparations isolated from newborn rats, we examined functions of the ventral medulla in respiratory rhythm generation, and located respiratory neurons in that region. Removal of the dorsal half of the medulla caused only modest reduction of the rate of inspiratory bursts from the cervical (C4 or C5) ventral root and moderate changes in the burst pattern. We describe here two types of respiratory neurons; Pre-I neurons that are presumably crucial in primary rhythm generation, and inspiratory (I) neurons that we presume to be important in inspiratory pattern generation. Pre-I neurons were located close to phenylethanolamine N-methyltransferase (PNMT)-immunoreactive (IR) neurons that are common in the reticular formation of the rostral ventrolateral medulla (RVL). Distributions of I neurons and Pre-I neurons overlapped in the RVL, and I neurons were also near the nucleus ambiguus in the more caudal part of the ventrolateral medulla. The results indicate that the ventral medulla is essential to inspiratory pattern generation as well as rhythm generation. It is suggested that the RVL is an important site in rhythm generation. The region of inspiratory pattern generation may extend more caudally in the ventral medulla.
在从新生大鼠分离出的脑干 - 脊髓标本中，我们研究了延髓腹侧在呼吸节律产生中的功能，并确定了该区域的呼吸神经元。切除延髓的背侧半部仅使颈（C4或C5）腹侧根吸气爆发频率适度降低，并使爆发模式发生中度改变。我们在此描述两种类型的呼吸神经元：推测在初级节律产生中起关键作用的前吸气（Pre - I）神经元，以及我们认为在吸气模式产生中很重要的吸气（I）神经元。Pre - I神经元位于苯乙醇胺N - 甲基转移酶（PNMT）免疫反应性（IR）神经元附近，后者在延髓头端腹外侧网状结构（RVL）中很常见。I神经元和Pre - I神经元在RVL中的分布重叠，并且I神经元在延髓腹外侧更靠尾端的部分也靠近疑核。结果表明，延髓腹侧对于吸气模式产生以及节律产生至关重要。提示RVL是节律产生的重要部位。吸气模式产生的区域可能在延髓腹侧更向尾端延伸。
