Abstract: the experiment was on the effects of extremely small intravenousinjection or injection of medbrain raphe of LSD on the behavior andfiring of the neurons in the dorsal hippocampus nucleus in the conscious,unanesthetized and unrestrained rabbits. The results show regular effectson the behavior,especially on the licking and turning activities.Therewas an interval in the peak of two behavioral changes from beginningto end. Intravenous injection or injection of medbrain raphe of LSDmay partially regulate the activity of neurons in the dorsal hippocamp-us, as was shown in the increase in the firing. frequency.and the changein the form of firing.

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