Buzsáki G, Penttonen M, Nádasdy Z, Bragin A
Center for Molecular and Behavioral Neuroscience, Rutgers, The State University of New Jersey, Newark 07102, USA.
Proc Natl Acad Sci U S A. 1996 Sep 3;93(18):9921-5. doi: 10.1073/pnas.93.18.9921.
The invasion of sodium spikes from the soma into dendrites was studied in hippocampal pyramidal cells by simultaneous extracellular and intracellular recordings in anesthetized rats and by simultaneous extracellular recordings of the somatic and dendritic potentials in freely behaving animals. During complex-spike patterns, recorded in the immobile or sleeping animal, dendritic invasion of successive spikes was substantially attenuated. Complex-spike bursts occurred in association with population discharge of CA3-CA1 pyramidal cells (sharp wave field events). Synaptic inhibition reduced the amplitude of sodium spikes in the dendrites and prevented the occurrence of calcium spikes. These findings indicate that (i) the voltage-dependent calcium influx into the dendrites is under the control of inhibitory neurons and (ii) the temporal coincidence of synaptic depolarization and activation of voltage-dependent calcium conductances by the backpropagating spikes during sharp wave bursts may be critical for synaptic plasticity in the intact hippocampus.
通过在麻醉大鼠中同时进行细胞外和细胞内记录，以及在自由活动动物中同时记录体细胞和树突电位，研究了海马锥体细胞中钠峰从胞体侵入树突的情况。在静止或睡眠动物中记录到的复杂峰模式期间，连续峰的树突侵入显著减弱。复杂峰爆发与CA3-CA1锥体细胞的群体放电（尖波场事件）相关。突触抑制降低了树突中钠峰的幅度，并阻止了钙峰的出现。这些发现表明：（i）电压依赖性钙流入树突受抑制性神经元控制；（ii）在尖波爆发期间，突触去极化与反向传播峰对电压依赖性钙电导的激活在时间上的重合可能对完整海马体中的突触可塑性至关重要。
