大鼠发育过程中伏隔核神经元的电生理学和形态学特性

ELECTROPHYSIOLOGY AND MORPHOLOGY OF NUCLEUS ACCUMBENS NEURONS IN DEVELOPING RATS

为探讨发育过程中伏膈核神经元的形态学和电生理学特性 ,运用脑片膜片钳全细胞记录技术结合细胞内标记技术对出生后 3 d(P3 ) 3 0 d(P3 0 )的伏隔核神经元进行了研究。结果表明 :出生后随着动物的不断成熟伏隔核神经元的树突野半径和树突总长度逐渐增长 ,树突分支逐渐增多 ;静息膜电位 (RMP)和输入阻抗 (IR)降低 ;动作电位的幅度升高 ,时程降低 ,突触后电流则无显著性变化。但在 P7以前 ,5 7.9%的神经元对刺激无反应 ,这类神经元主要见于幼稚动物 ,其静息膜电位与输入阻抗较高。提示 ,发育过程中伏隔核神经元的形态和功能成熟密切相关 ,幼稚与成熟神经元在细胞形态学和电生理学以及突触功能上的显著差异表明幼稚和成熟神经元对信号的输入、输出整合不同。

To explore the electrophysiological and morphological properties of nucleus accumbens neurons of rat during development, patch clamp whole cell recording and intracellular staining techniques were applied to neurons from postnatal day 3(P3) to P30. With gradual maturation of rats, the radius of dendritic fields, the total lengths of the dendrites and the dendritic branches of nucleus accumbens neurons increased. In addition, resting membrane potential(RMP) and input resistance(IR) decreased and the amplitude of action potential(AP) enhanced but with a decreased duration. Post synaptic currents(PSCs) did not change significantly, but 57.9% neurons before P7 were not responsive to stimulus, which was mostly observed in immature rats with higher RMP and IR. These results suggest the close coincidence of the electrophysiological and morphological maturations in nucleus accumbens neurons, and that the differences of characteristics in electrophysiology, morphology and synaptic transmission between immature and mature neurons reflect the different integration modes of input and output.