Oddie S D, Stefanek W, Kirk I J, Bland B H
Department of Psychology, University of Calgary, Alberta, Canada.
J Neurosci. 1996 Mar 1;16(5):1948-56. doi: 10.1523/JNEUROSCI.16-05-01948.1996.
Rats were implanted chronically with hippocampal recording electrodes, a microinfusion guide cannula aimed at the medial septal nucleus, and an electrode for electrical stimulation of the posterior hypothalamic nucleus (PH). PH stimulation elicited running in rats placed in a wheel and simultaneously occurring hippocampal theta field activity (HPC-theta). In the preprocaine (PRE) testing condition, a positive linear relationship was demonstrated among the intensity of electrical stimulation of the PH, wheel-running speed, and the peak frequency of HPC-theta. HPC-theta amplitude reached an asymptote at the lowest levels of electrical stimulation of the PH. Procaine hydrochloride (1.5 microliters, 20% solution), a local anesthetic, was then infused into the medial septal nucleus (MS). Five minutes after the infusion, PH stimulation no longer induced wheel-running behavior or HPC-theta, and the remaining irregular field activity was significantly reduced in amplitude. Fifteen minutes after the procaine infusion, PH stimulation still did not elicit HPC-theta or running behavior in the majority of animals but did evoke large-amplitude sharp-waves. Thirty minutes after the procaine infusion, PH stimulation again elicited HPC-theta and running behavior, but HPC-theta peak frequency and running speeds were both significantly reduced compared with PRE values. Forty-five minutes after the infusion, HPC-theta amplitude had recovered to PRE values, but HPC-theta frequency and running speeds elicited by PH stimulation were still significantly reduced. By 60 min after procaine administration, the amplitude and frequency of HPC-theta and the running speeds elicited by PH stimulation recovered to PRE values. Multiple regression analysis revealed that the recovery pattern of running behavior reflected the frequency rather than the amplitude of HPC-theta. Neither saline control infusions into the MS nor procaine infusions into the lateral septum and paraventricular thalamic nucleus affected HPC-theta or running behavior. These findings are consistent with the notion that both the locomotor activity and "movement-related" HPC-theta frequency induced by electrically stimulating the PH were attributable to ascending activation of a hypothalamo-septal pathway and not to activation of descending brainstem or peripheral motor systems.
将慢性记录电极植入大鼠海马体，将微量注射引导套管对准内侧隔核，并植入用于电刺激下丘脑后核（PH）的电极。刺激PH可使置于转轮中的大鼠奔跑，并同时出现海马体θ波场活动（HPC-θ）。在普鲁卡因预处理（PRE）测试条件下，PH电刺激强度、转轮奔跑速度和HPC-θ峰值频率之间呈现正线性关系。在最低强度的PH电刺激下，HPC-θ振幅达到渐近线。然后将局部麻醉剂盐酸普鲁卡因（1.5微升，20%溶液）注入内侧隔核（MS）。注射后5分钟，刺激PH不再诱发转轮奔跑行为或HPC-θ，其余不规则场活动的振幅显著降低。普鲁卡因注射15分钟后，在大多数动物中，刺激PH仍未诱发HPC-θ或奔跑行为，但诱发了大幅度的尖波。普鲁卡因注射30分钟后，刺激PH再次诱发HPC-θ和奔跑行为，但与PRE值相比，HPC-θ峰值频率和奔跑速度均显著降低。注射45分钟后，HPC-θ振幅恢复到PRE值，但刺激PH诱发的HPC-θ频率和奔跑速度仍显著降低。到普鲁卡因给药60分钟时，刺激PH诱发的HPC-θ振幅和频率以及奔跑速度恢复到PRE值。多元回归分析表明，奔跑行为的恢复模式反映的是HPC-θ的频率而非振幅。向MS注射生理盐水对照以及向外侧隔核和室旁丘脑核注射普鲁卡因均不影响HPC-θ或奔跑行为。这些发现与以下观点一致，即电刺激PH诱发的运动活动和“与运动相关的”HPC-θ频率均归因于下丘脑-隔区通路的上行激活，而非脑干下行或外周运动系统的激活。
