Importance of Polysynaptic Inputs and Horizontal Connectivity in the Generation of Tetanus-Induced Long-Term Potentiation in the Rat Auditory Cortex
Importance of Polysynaptic Inputs and Horizontal Connectivity in the Generation of Tetanus-Induced Long-Term Potentiation in the Rat Auditory Cortex
复制标题
多突触输入和水平连接在破伤风引起的大鼠听觉皮层长期增强作用中的重要性
作者：
M. Kudoh;K. Shibuki
成年大鼠听皮层颗粒上锥体神经元在强直性白色物质刺激（TS）后出现明显的群体峰电位长时程增强（LTP）。为了确定这种标记的LTP是否对AC具有特异性，将大鼠AC切片中的LTP与视觉皮层（VC）切片中的LTP进行比较。TS诱发的LTP振幅AC是VC的2倍。采用穿孔斑片或全细胞记录法研究了EPSPs的LTP。虽然AC的TS诱发的EPSP的LTP幅度大于VC，但低频刺激与电流注入配对诱发的LTP没有发现皮层差异。新皮层LTP依赖于NMDA受体的激活，并且LTP的诱导需要突触后去极化以去除NMDA受体的Mg 2+阻断。TS引起的AC颗粒上锥体神经元突触后去极化显著大于VC。切断颗粒上水平连接导致AC的去极化幅度减小，但VC的去极化幅度增加。皮质差异TS诱导的LTP减少在切片中，在颗粒层的水平连接被切断。AC颗粒上锥体神经元的水平轴突侧支密度约为VC的2倍。这些结果强烈表明，在TS和AC中产生的显着的LTP的多突触和突触后去极化归因于发达的水平轴突侧支的颗粒上锥体神经元在AC中。
Supragranular pyramidal neurons in the adult rat auditory cortex (AC) show marked long-term potentiation (LTP) of population spikes after tetanic white matter stimulation (TS). For determination of whether this marked LTP is specific to AC, LTP in rat AC slices was compared with LTP in slices of the visual cortex (VC). The amplitude of TS-induced LTP in AC was twice that in VC. LTP of EPSPs was also studied with perforated patch or whole-cell recording. Although the amplitude of TS-induced LTP of EPSPs in AC was larger that in VC, no cortical difference was found in LTP elicited by low-frequency stimulation paired with current injection. Neocortical LTP is dependent on the activation of NMDA receptors, and induction of LTP requires postsynaptic depolarization for removal of Mg2+blockade of NMDA receptors. The postsynaptic depolarization elicited by TS in supragranular pyramidal neurons in AC was significantly larger than that in VC. Cutting of supragranular horizontal connections resulted in a decrease in the depolarization amplitude in AC but an increase in the depolarization amplitude in VC. The cortical difference in TS-induced LTP was diminished in the slices in which horizontal connections in supragranular layers were cut. The estimated density of horizontal axon collaterals of supragranular pyramidal neurons in AC was approximately twice that in VC. These results strongly suggest that the marked polysynaptic and postsynaptic depolarization during TS and the resulting marked LTP in AC are attributed to well developed horizontal axon collaterals of supragranular pyramidal neurons in AC.
影响因子：
2.5
作者：
CHAGNACAMITAI, Y;CONNORS, BW
通讯作者：
CONNORS, BW
影响因子：
2.5
作者：
FRANOWICZ, MN;BARTH, DS
通讯作者：
BARTH, DS