Developmental changes in the electrophysiological properties and response characteristics of Manduca antennal-lobe neurons
Developmental changes in the electrophysiological properties and response characteristics of Manduca antennal-lobe neurons
复制标题
DOI：
10.1152/jn.2002.87.6.2650
复制
发表时间：
2002-06-01
影响因子：
2.5
通讯作者：
Hildebrand, JG
中科院分区：
文献类型：
--
作者：
Mercer, AR;Hildebrand, JG
利用全细胞膜片钳记录，研究了与狮身人面像成虫发育有关的触角叶(AL)神经元的电生理特性和反应特性的变化。分别在体外培养的弥散性AL神经元和半完整脑标本中原位培养的内侧组AL神经元中检测全细胞电流分布和电兴奋性。在变态成体发育的18个阶段的第2-4阶段，全细胞电流分布以大的外向(K+)电流为主。在这一阶段可以诱发钙依赖的动作电位，但只有一小部分细胞出现钠峰。从第3期到第10期，表现出快速激活的瞬时钠电流的AL神经元比例迅速增加，许多体外细胞在这个时候表现出自发的棘波活动。随着发育的进展，动作电位波形的持续时间变短，幅度变大。细胞类型的不同在自发活动的发生率以及AL神经元的电生理特性和反应特征方面的差异，在变态后期最为明显。虽然在变态早期(阶段1-2)移除ALS的触角感觉输入对细胞兴奋性的发展没有可检测到的影响，但在培养液中加入5-羟色胺后，来自阶段4的体外培养的幼虫中有明显更高比例的神经元显示出基于钠的动作电位。在发育中的Manduca AL神经元中，电兴奋性的特征形式以及它们被5-羟色胺调节，似乎在ALS的功能发育中发挥着核心作用。
Using whole cell patch-clamp recordings, we have examined changes in the electrophysiological properties and response characteristics of antennal lobe (AL) neurons associated with the metamorphic adult development of the sphinx moth, Manduca sexta. Whole cell current profiles and electrical excitability were examined in dispersed AL neurons in vitro, and in medial-group AL neurons in situ in semi-intact brain preparations. Around stages 2-4 of the 18 stages of metamorphic adult development, whole cell current profiles were dominated by large outward (K+) currents. Calcium-dependent action potentials could be elicited at this stage, but only a small percentage of cells exhibited sodium spikes. From stages 3 to 10, there was a rapid increase in the proportion of AL neurons exhibiting rapidly activating, transient sodium currents, and many cells in vitro exhibited spontaneous bursts of spike activity at this time. As development progressed, action-potential waveforms became shorter in duration and larger in amplitude. Cell-type-specific differences in the prevalence of spontaneous activity, and in the electrophysiological properties and response characteristics of AL neurons, were most apparent late in metamorphosis. While removal of antennal sensory input to the ALs early (stage 1-2) in metamorphosis had no detectable effect on the development of cell excitability, a significantly higher percentage of neurons in vitro from stage 4 pupae exhibited sodium-based action potentials following the addition of serotonin to the culture medium. Characteristic forms of electrical excitability in developing Manduca AL neurons, and their modulation by serotonin, seem likely to play a central role in the functional development of the ALs.