Sil'kis I G, Rapoport S Sh, Veber N V, Gushchin A M
Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow.
Neurosci Behav Physiol. 1994 Nov-Dec;24(6):500-6. doi: 10.1007/BF02360175.
It has been demonstrated that long-term posttetanic heterosynaptic depression (LTHD), manifested in the form of a prolonged decrease in the probability of monosynaptic responses of the cell to stimulation of that afferent pathway which was not activated during conditioning tetanization of another input, takes place in the neocortex, as it does in the hippocampus. LTHD is characterized by such properties as its long-term character, cooperativity, and nonspecificity of input. LTHD in the nonconditioned input and long-term posttetanic potentiation or long-term posttetanic homosynaptic depression in the conditioned input may develop both in parallel or independantly of one another. It is hypothesized on the basis of the results obtained that LTHD (as is the case with LTP and LTD) is a calcium-dependant phenomenon, and that the achievement of a specific level of depolarization of the membrane in the region of the disposition of the inactive synapses is required for its occurrence. "Contrasting," i.e., a relative increase in the efficiency of transmission in the activating synapse, may be effected through LTHD; LTHD may be one of the mechanisms underlying forgetting.
业已证明，长期强直后异突触抑制（LTHD）在新皮层中会出现，如同在海马体中一样，其表现形式为，在对另一个输入进行条件性强直刺激期间未被激活的传入通路受到刺激时，细胞单突触反应概率出现长时间下降。LTHD具有长期特性、协同性和输入非特异性等特点。非条件输入中的LTHD以及条件输入中的长期强直后增强或长期强直后同突触抑制可能会相互平行或独立地发展。根据所获结果推测，LTHD（与长时程增强和长时程抑制情况相同）是一种钙依赖现象，并且其发生需要在无活性突触所在区域达到特定水平的膜去极化。“对比”，即在激活突触中传递效率的相对增加，可能通过LTHD实现；LTHD可能是遗忘背后的机制之一。
