当前位置： SCI文献检索 > JOURNAL OF NEUROPHYSIOLOGY期刊下所有文献 > Functional development of intrinsic properties in ganglion cells of the mammalian retina.

Functional development of intrinsic properties in ganglion cells of the mammalian retina.

Abstract：

:Senosory neurons manifest pronounced changes in excitability during maturation, but the factors contributing to this ubiquitous developmental phenomenon are not well understood. To assess the contribution of intrinsic membrane properties to such changes in excitability, in the present study whole cell patch-clamp recordings were made from developing ganglion cells in the intact retina of postnatal rats. During a relatively brief developmental period (postnatal days P7-P27) ganglion cells exhibited pronounced changes in the discharge patterns generated by depolarizing current injections. The youngest cells (P7-P17) typically responded to maintained depolarizations with only a single spike or a rapidly adapting discharge pattern. In contrast, the predominant response mode of more mature cells (P21-P27) was a series of repetitive discharges that lasted for the duration of the depolarization period, and by P25 all cells responded in this manner. These functional changes characterized all three morphologically defined cell classes identified by intracellular labeling with Lucifer yellow. To determine if expression of the potassium current (Ia) and the kinetics of the Na-channel related to the increased excitability of developing ganglion cells described above, current- and voltage-clamp recordings were made from individual neurons. The different firing patterns manifested by developing retinal ganglion cells did not reflect the presence or absence of the Ia conductance, although cells expressing Ia tended to generate spikes of shorter duration. With maturation the speed of recovery from inactivation of the Na current increased markedly and this related to the increased excitability of developing ganglion cells. Neurons yielding only a single spike to maintained depolarization were characterized by the slowest speed of recovery; cells with rapidly adapting discharges showed a faster recovery and those capable of repetitive firing recovered fastest from Na-channel inactivation. It is suggested that these changes in intrinsic membrane properties may relate to the different functional roles subserved by ganglion cells during development.

journal_name

J Neurophysiol

journal_title

Journal of neurophysiology

authors

Wang GY,Ratto G,Bisti S,Chalupa LM

doi

10.1152/jn.1997.78.6.2895

subject

Has Abstract

pub_date

1997-12-01 00:00:00

pages

2895-903

issue

eissn

0022-3077

issn

1522-1598

journal_volume

pub_type

杂志文章

在线工具

Functional development of intrinsic properties in ganglion cells of the mammalian retina.