新生大鼠海马CA1神经元突触反应和树突分枝的关系(英文)

The relationship between synaptic responses and dendritic arborization in neonatal hippocampal CA1 neurons

应用盲法脑片膜片钳记录并结合biocytin细胞内染色方法 ,研究了新生大鼠 (生后 3～ 5d)离体海马脑片CA1锥体神经元突触反应和树突分枝的关系。发现 ,在生后 3～ 5d锥体神经元的形态呈现多形性。 5 2 %的神经元具有分枝很少的树突 ,并且既无自发性也无诱发性的突触后电流 (postsynapticcurrents,PSCs) ;4 8%的神经元具有较为发达的树突分枝且当刺激海马辐射层时 ,可引起突触反应。而且在半最大刺激强度时引起的PSCs的幅值与神经元顶树突的长度及终末分枝数呈正相关。上述研究结果表明 ,CA1锥体神经元的反应性是与顶树突的分枝状况相关的。

In vitro hippocampal slices were prepared from neonate rats (3～5 days old). Whole cell patch clamp recordings were obtained from CA1 neurons by using voltage clamp technique combined with biocytin intracellular staining method to study the relationship between the evoked synaptic responses and the dendritic arborization of pyramidal neurons. We reported that during the period of P3～5 pyramidal neurons were morphologically heterogeneous. Fifty two percent of the neurons had poorly branched apical dendrites, with neither spontaneous nor evoked postsynaptic currents (PSCs); 48% of the neurons had much more developed dendritic arborization and synaptic responses when stimulation electrode was positioned in the stratum radiatum. Furthermore, the amplitudes of PSCs evoked at half maximal intensity of stimuli positively correlated with the apical dendritic length and number of terminal branches. The present results demonstrate that the apical dendritic arborization relates to the responsiveness of CA1 pyramidal neurons to stimulation of stratum radiatum. \[