Hu B
Loeb Research Institute, Ottawa Civic Hospital, University of Ottawa, Canada.
Acta Physiol Scand. 1993 Jun;148(2):109-13. doi: 10.1111/j.1748-1716.1993.tb09539.x.
Thalamic relay neurons were recorded from the dorsolateral and lateroposterior nuclei of the rat thalamus in a superfused explant preparation. The mean membrane potential of these cells was -67 +/- 7 mV, input resistance 114 +/- 31 M omega and spike amplitude 75 +/- 6 mV. Low-threshold slow membrane potential oscillations (1-4 Hz) were present in about 46% of the neurons. They occurred either spontaneously or following a membrane potential perturbation. In a subpopulation of cells, we also observed a high-threshold membrane oscillation when cells were depolarized above -45 mV. This oscillation consisted of bursts of low-amplitude spikes interrupted by rhythmic after-hyperpolarizations. Stimulation of the corticothalamic pathway elicited prolonged inhibitory postsynaptic potentials in associational thalamic neurons. In the presence of picrotoxin, corticothalamic input evoked prominent excitatory postsynaptic responses that showed marked short-term synaptic plasticity. Our results suggest that associational thalamic neurons maintained in vitro have a strong tendency to exhibit membrane oscillations. In addition, they receive a direct excitatory cortical input that remained functional in explant preparation.
在一种灌流脑片制备中，从大鼠丘脑的背外侧核和后外侧核记录丘脑中继神经元。这些细胞的平均膜电位为-67±7 mV，输入电阻为114±31 MΩ，动作电位幅度为75±6 mV。约46%的神经元存在低阈值慢膜电位振荡（1-4 Hz）。它们可自发出现或在膜电位受到扰动后出现。在一部分细胞中，当细胞去极化至-45 mV以上时，我们还观察到高阈值膜振荡。这种振荡由低幅度动作电位簇组成，中间穿插有节律性的超极化后电位。刺激皮质丘脑通路可在联合丘脑神经元中诱发长时间的抑制性突触后电位。在存在荷包牡丹碱的情况下，皮质丘脑输入诱发了明显的兴奋性突触后反应，这些反应表现出显著的短期突触可塑性。我们的结果表明，体外培养的联合丘脑神经元有强烈的膜振荡倾向。此外，它们接受直接的兴奋性皮质输入，该输入在脑片制备中仍保持功能。
