Influence of raphe nuclei on neuronal transmission from perforant pathway through dentate gyrus.
Influence of raphe nuclei on neuronal transmission from perforant pathway through dentate gyrus.
复制标题
中缝核对穿通通路通过齿状回的神经元传递的影响。
DOI：
10.1152/jn.1980.44.5.937
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发表时间：
1980
影响因子：
2.5
通讯作者：
Winson,J
中科院分区：
文献类型：
--
作者：
Winson,J
1. 在长期准备的自由运动大鼠中，电刺激穿孔通路并记录同侧齿状回细胞外的单突触反应。在一些测试中，在激活穿孔通路之前，还对中缝正中核（mr）施加了刺激。实验在两种行为状态下进行：慢波睡眠（SWS）和静止警觉状态（SAL）。记录了两种不同的诱发反应：由神经元动作电位（诱发动作电位或EAPs）同步放电引起的诱发反应和由兴奋性突触活动（诱发突触电位或ESPs）产生的诱发反应。2. 正如之前报道的那样（38），射孔通道刺激在SWS期间引发的eap比SAL期间更大。预先刺激mr（预刺激）的应用显著增加了在SWS期间观察到的已经升高的eap。在SAL期间，eap不受预刺激的影响。3. 在SWS期间，eap出现增强的最小延迟时间（mr和射孔路径刺激之间的时间）约为5 ms。延迟时间为25-40毫秒时，增强达到最大值，延迟时间为150毫秒4。与之前的实验一样（38），在射孔通路刺激后，在齿状回分子层记录的esp在SAL期间比SWS期间更大。在SWS和SAL过程中，mr的预刺激对任何水平分子层的esp都没有显著影响。5. 在齿状回中高增益地记录了穿孔路径传入波。发现其振幅仅依赖于穿孔路径刺激强度，而不依赖于行为状态或mr. 6的预刺激。在Chloropent（82%水化氯醛，18%戊巴比妥；Fort Dodge实验室，Fort Dodge， IA）麻醉的制剂中，对脑桥和髓质内的多个位点进行预刺激，包括在SWS中mr， As，预刺激mr导致EAPs增强，最小延迟时间为5 ms。当刺激其他中缝核（中缝背核、桥脑核、大肌核和苍白肌核）时，观察到类似的增强反应，但当刺激其他脑干部位时，没有观察到增强反应。中缝核产生增强eap的阈值刺激强度小于30微a。7. 在自由运动的动物中，首先确定了SWS期间的EAP反应明显大于SAL期间。然后在mr.的背侧水平做中线损伤，在损伤之后，两种行为期间记录的eap的大小不再有任何显著差异。8. 这些发现表明，在这种行为状态下，中缝核产生的强直影响可能参与了通过齿状回观察到的神经元传递的促进。
1. In chronically prepared, freely moving rats, electrical stimulation was applied to the perforant pathway and monosynaptic responses were recorded extracellularly in the ipsilateral dentate gyrus. In some tests a stimulus was also applied to the median raphe nucleus (mr) prior to activating the perforant pathway. Experiments were performed during two behavioral conditions: slow-wave sleep (SWS) and the still, alert state (SAL). Two varieties of evoked responses were recorded: those due to synchronous firing of neuronal action potentials (evoked action potentials or EAPs) and those produced by excitatory synaptic activity (evoked synaptic potentials or ESPs). 2. As reported previously (38), perforant path stimulation elicited EAPs of greater magnitude during SWS than during SAL. The application of a prior stimulus to mr (prestimulation) markedly increased the already elevated EAPs observed during SWS. The EAPs during SAL were unaffected by prestimulation. 3. The minimum delay time (time between mr and perforant path stimuli) at which the augmentation of the EAPs appeared during SWS was approximately 5 ms. The augmentation reached a maximum at delay times of 25-40 ms and was present up to a delay time of 150 ms. 4. As in former experiments (38), ESPs recorded in the molecular layer of the dentate gyrus after perforant path stimulation were found to be greater during SAL than during SWS. Prestimulation of mr had no significant effect on the ESPs at any level of the molecular layer during either SWS or SAL. 5. The perforant path afferent volley was recorded at high gain in the dentate gyrus. Its amplitude was found to be solely dependent on perforant path stimulus intensity and not on behavioral state or the prestimulation of mr. 6. In preparations anesthetized with Chloropent (82% chloral hydrate, 18% pentobarbital; Fort Dodge Laboratories, Fort Dodge, IA), prestimulation was applied at each of a number of loci within the pons and medulla, including mr, As in SWS, prestimulating mr resulted in augmented EAPs with a minimum delay time of 5 ms. Similar augmented responses were observed when stimulation was applied at other raphe nuclei (dorsal raphe, pontis, magnus, and pallidus), but there was no augmentation when stimulation was applied at other brain stem sites. Threshold stimulus intensities for producing augmented EAPs in the raphe nuclei were less than 30 microA. 7. In freely moving animals it was first established that the EAP responses during SWS were markedly greater than during SAL. Midline lesions were then made at the rostrocaudal level of mr. Following the lesions, there was no longer any significant difference in the magnitude of the EAPs recorded during the two behaviors. 8. These findings suggest that tonic influences arising from raphe nuclei during SWS may be involved in the facilitation of neuronal transmission through the dentate gyrus observed during this behavioral state.