Uno Atsuhiko, Idoux Erwin, Beraneck Mathieu, Vidal Pierre-Paul, Moore Lee E, Wilson Victor J, Vibert Nicolas
Laboratoire de Neurobiologie des Réseaux Sensorimoteurs, Centre National de la Recherche Scientifique UMR 7060, Université Paris 5, Centre Universitaire des Saints-Pères, 75270 Paris Cédex 06, France.
J Neurophysiol. 2003 Sep;90(3):1689-703. doi: 10.1152/jn.00201.2003. Epub 2003 May 21.
In vitro intracellular recordings of central vestibular neurons have been restricted so far to the medial vestibular nucleus (MVN). We performed intracellular recordings of large Deiters' neurons in the lateral vestibular nucleus (LVN) to determine their static and dynamic membrane properties, and compare them with those of type A and type B neurons identified in the MVN. Unlike MVN neurons (MVNn), the giant-size LVN neurons (LVNn) form a homogeneous population of cells characterized by sharp spikes, a low-amplitude, biphasic after-hyperpolarization like type B MVNn, but also an A-like rectification like type A MVNn. In accordance with their lower membrane resistance, the sensitivity of LVNn to current injection was lower than that of MVNn over a large range of frequencies. The main difference between LVNn and MVNn was that the Bode plots showing the sensitivity of LVNn as a function of stimulation frequency were flatter than those of MVNn, and displayed a weaker resonance. Furthermore, most LVNn did not show a gradual decrease of their firing rate modulation in the frequency range where it was observed in MVNn. LVNn synchronized their firing with the depolarizing phase of high-frequency sinusoidal current injections. In vivo studies have shown that the MVN would be mainly involved in gaze control, whereas the giant LVNn that project to the spinal cord are involved in the control of posture. We suggest that the difference in the membrane properties of LVNn and MVNn may reflect their specific physiological roles.
迄今为止，对中枢前庭神经元的体外细胞内记录仅限于内侧前庭核（MVN）。我们对外侧前庭核（LVN）中的大Deiters神经元进行了细胞内记录，以确定它们的静态和动态膜特性，并将其与在MVN中鉴定出的A型和B型神经元的特性进行比较。与MVN神经元（MVNn）不同，巨大的LVN神经元（LVNn）形成了一个同质的细胞群体，其特征是尖峰、低幅度、双相超极化后电位，类似于B型MVNn，但也有类似于A型MVNn的A类整流。由于其较低的膜电阻，在很大的频率范围内，LVNn对电流注入的敏感性低于MVNn。LVNn和MVNn之间的主要区别在于，显示LVNn敏感性作为刺激频率函数的波特图比MVNn的更平坦，并且共振较弱。此外，大多数LVNn在MVNn中观察到的频率范围内，其放电率调制没有逐渐下降。LVNn在高频正弦电流注入的去极化阶段使它们的放电同步。体内研究表明，MVN主要参与注视控制，而投射到脊髓的巨大LVNn则参与姿势控制。我们认为，LVNn和MVNn膜特性的差异可能反映了它们特定的生理作用。
