Pharmacological suppression of the median raphe nucleus with serotonin1A agonists, 8-OH-DPAT and buspirone, produces hippocampal theta rhythm in the rat.
Pharmacological suppression of the median raphe nucleus with serotonin1A agonists, 8-OH-DPAT and buspirone, produces hippocampal theta rhythm in the rat.
复制标题
使用 5-羟色胺 1A 激动剂、8-OH-DPAT 和丁螺环酮对中缝核进行药理学抑制，可在大鼠中产生海马 θ 节律。
DOI：
10.1016/0306-4522(94)90255-0
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发表时间：
1994
期刊：
影响因子：
3.3
通讯作者：
Fortin,WJ
中科院分区：
文献类型：
--
作者：
Vertes,RP;Kinney,GG;Kocsis,B;Fortin,WJ
在乌拉坦麻醉大鼠中缝正中核内微量注射盐酸普鲁卡因和5-羟色胺1受体激动剂8-OH-DPAT和丁螺环酮，观察其对海马区脑电的影响。在中缝正中核注射普鲁卡因、8-OH-DPAT或丁螺环酮，可在短潜伏期和长时间内使海马脑电从自发的去同步化模式转变为同步化模式(theta节律)。普鲁卡因的平均潜伏期为52 S，平均持续时间为21.75min，丁螺环酮的平均潜伏期为2min，平均持续时间为34.5min。8-OH-DPAT注射与潜伏期之间存在剂量依赖关系，但与持续时间无关。小剂量(0.5μg)8-OH-DPAT的平均潜伏期为1.33min，大剂量(3.0μg)的平均潜伏期为1.17min。注射8-OH-DPAT产生的theta平均持续时间为62分钟。将这些物质分别注入中缝正中核的背侧、外侧或吻尾结构(分别为中缝背核、桥脑网状结构、尾侧线状核或中缝脑桥)，均不能产生theta，或在少数情况下在很长的潜伏期(24分钟)产生theta。在中缝正中核或对照结构注射生理盐水无效。向中缝正中核注入抑制其活性的药物(普鲁卡因和5-羟色胺1激动剂)产生theta的证据表明，含有5-羟色胺的中缝正中核神经元通常抑制theta或参与控制海马的去同步化。目前的发现与先前的工作一致，即刺激中缝中核使海马脑电去同步化，而中缝正中核损伤产生恒定的theta，但与5-羟色胺能机制可能在theta节律的产生中发挥作用的说法不一致。
The effects on the hippocampal electroencephalogram of microinjections of procaine hydrochloride and the serotonin1aagonists, 8-OH-DPAT and buspirone, into the median raphe nucleus were examined in the urethane anesthetized rat. Injections of procaine, 8-OH-DPAT or buspirone into the median raphe nucleus produced a change in the hippocampal electroencephalogram from a spontaneous desynchronized pattern to a synchronized pattern (theta rhythm) within short latencies and for long durations post-injection. Procaine was shown to elicit theta at a mean latency of 52 s and for a mean duration of 21.75 min; buspirone at a mean latency of 2 min and for a mean duration of 34.5 min. A dose dependent relationship was observed between 8-OH-DPAT injections and latencies but not durations. Small doses (0.5μg) of 8-OH-DPAT produced theta at a mean latency of 1.33 min and large doses (3.0μg) at a mean latency of 1.17 min. 8-OH-DPAT injections generated theta for a mean duration of 62 min. Injections of each of these substances into structures dorsal, lateral or rostrocaudal to the median raphe (dorsal raphe nucleus, pontine reticular formation, caudal linear nucleus or raphe pontis, respectively) failed to generate theta or in a few cases produced theta at very long latencies (> 24 min). Saline injections in the median raphe nucleus or control structures were without effect. The demonstration that agents injected into the median raphe nucleus that inhibit its activity (procaine and serotonin1aagonists) produce theta indicate that serotonin-containing median raphe neurons normally suppress theta or are involved in the control of hippocampal desynchronization.The present findings are consistent with previous work showing that median raphe nucleus stimulation desynchronizes the hippocampal electroencephalogram and that median raphe nucleus lesions produce constant theta, but are at odds with the proposal that serotonergic mechanisms may play a role in the generation of the theta rhythm.