Soares Daphne, Chitwood Raymond A, Hyson Richard L, Carr Catherine E
Department of Biology, University of Maryland, College Park, Maryland 20740-4415, USA.
J Neurophysiol. 2002 Jul;88(1):152-62. doi: 10.1152/jn.2002.88.1.152.
In vitro whole cell recording revealed intrinsic firing properties and single-cell morphology in the cochlear nucleus angularis (NA) of the chick. We classified three major classes of neurons: one-spike, damped, and tonic. A delayed inward rectifying current was observed in all classes during hyperpolarization injections. One-spike neurons responded with a single spike to depolarizing current injection and had small (stubby) radiate dendritic trees. Damped neurons responded with only a few spikes at the onset of positive current injection. More positive current inputs led to a damped response. Damped cell dendrites had a planar orientation parallel to the isofrequency axis in NA. Tonic cells produced trains of action potentials in response to a depolarizing current injection. Three variations of the tonic type had multipolar morphology, with dendrites oriented either radially (I and III) or perpendicular to the tonotopic axis (II; vertical). Tonics I and III differed in the shape of their action potential undershoot. Thus NA is both physiologically and morphologically heterogeneous.
体外全细胞记录揭示了雏鸡耳蜗核角状核（NA）的内在放电特性和单细胞形态。我们将神经元分为三大类：单峰型、衰减型和紧张型。在超极化注入期间，所有类型的神经元均观察到延迟内向整流电流。单峰型神经元在去极化电流注入时以单个峰电位响应，并且具有小（短粗）的放射状树突。衰减型神经元在正向电流注入开始时仅以少数几个峰电位响应。更多的正向电流输入导致衰减响应。衰减型细胞的树突在NA中具有与等频率轴平行的平面取向。紧张型细胞在去极化电流注入时产生一系列动作电位。紧张型的三种变体具有多极形态，其树突要么呈放射状（I型和III型），要么垂直于音频轴（II型；垂直）。紧张型I型和III型在动作电位负后电位的形状上有所不同。因此，NA在生理和形态上都是异质的。
