Induction and transient suppression of long-term potentiation in the peri- and postrhinal cortices following theta-related stimulation of hippocampal field CA1
Induction and transient suppression of long-term potentiation in the peri- and postrhinal cortices following theta-related stimulation of hippocampal field CA1
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DOI：
10.1016/s0006-8993(97)01151-7
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发表时间：
1998-01-05
期刊：
影响因子：
2.9
通讯作者：
Otto, TA
中科院分区：
文献类型：
--
作者：
Cousens, G;Otto, TA
在与可能的助记处理期间相关的行为事件期间，大鼠的 CA1 锥体细胞通常以高频脉冲（“复杂尖峰”）或单尖峰重复放电，这两种尖峰都与海马 theta 节律紧密锁相。有趣的是，模仿重复的、与学习相关的复杂尖峰放电的模式刺激最适合诱导 CA1 兴奋性场电位的长期增强 (LTP)，而模仿 theta 相关的单一动作电位的模式刺激会在这些相同的突触处导致强大而持久的去电位。本研究的目的是确定海马刺激的这些生理相关模式对从 CA1 到鼻周和鼻后皮质 (PRh) 的单突触投射的突触功效有相似的影响程度，这些区域被认为在多种形式的学习和记忆中发挥着重要作用。 CA1 的单脉冲刺激在 PRh 中引起小幅度、短潜伏期的群体兴奋性突触后电位 (EPSP)。传递到 CA1 的 Theta 突发刺激（TBS；n = 8）可靠地增强了 PRh EPSP 斜率至少 30 分钟。 TBS 后 5 分钟将 Theta 脉冲刺激（TPS；5 Hz；n = 4）传递至 CA1，相对于强化对照制剂，EPSP 斜率显着但短暂地受到抑制。总的来说，这些数据表明海马激活的 θ 相关模式可以可靠地诱导和短暂抑制 PRh 中的 LTP，并且与行为相关的 CA1 单元活动的 θ 调节模式可能导致其鼻皮质目标内突触强度的长期和短期改变的概念是一致的。 (C) 1998 Elsevier Science B.V.
During behavioral events associated with periods of likely mnemonic processing, CA1 pyramidal cells in rats typically discharge repetitively in either high-frequency bursts ('complex spikes') or single spikes, both of which are tightly phase-locked to the hippocampal theta rhythm. Interestingly, patterned stimulation which mimics the repetitive, learning-related complex spike discharges are optimal for inducing long-term potentiation (LTP) of excitatory field potentials in CA1, and patterned stimulation which mimics the theta-related single action potentials results in a robust and lasting depotentiation at these same synapses. The aim of the present study was to determine the extent to which these physiologically-relevant patterns of hippocampal stimulation have similar effects on synaptic efficacy in the monosynaptic projection from CA1 to the perirhinal and postrhinal cortices (PRh), areas thought to play a prominent role in many forms of learning and memory. Single-pulse stimulation of CA1 evoked a small amplitude, short latency population excitatory postsynaptic potential (EPSP) in the PRh. Theta-burst stimulation (TBS; n = 8) delivered to CA1 reliably potentiated the PRh EPSP slope for at least 30 min. Theta-pulse stimulation (TPS; 5 Hz; n = 4) delivered to CA1 5 min after TBS substantially but transiently suppressed EPSP slope relative to that of potentiated control preparations. Collectively these data suggest that theta-related patterns of hippocampal activation can reliably induce and transiently suppress LTP in PRh, and are consistent with the notion that behaviorally-relevant, theta-modulated patterns of CA1 unit activity may result in both long-and short-term alterations of synaptic strength within their rhinal cortical targets. (C) 1998 Elsevier Science B.V.