State-dependent learning produced by chlordiazepoxide and its transfer at different dose levels

In Experiment I, the rat was given 15 mg/kg of chlordiazepoxide (CDP) and trained on a black-white discrimination task, motivated by electric shocks; the same animal, when given saline, was treated similarly with the reversed cue relationship on different and usually alternate sessions. Training was continued until a learning criterion under both drug and saline states and then tested with only one of five testing CDP doses (2.5, 5, 10, 20 and 25 mg/kg). During training, the rat made more errors under drug than under saline but there were little differences in starting and running times at least during the last sessions. In the transfer test, choice responses showed a bi-directional gradient around the training dose as in stimulus generalization gradient. Experiment II was identical to Experiment I, except that the same drug was tested at all five transfer doses and the resulting transfer gradient was a simple monotonic increasing function of dose levels. Discrepancy between the two experiments was discussed.

Abolition of the hippocampal theta activity and drug-learning dissociation

Rats were trained to escape electric shock by running into one arm of a T-maze on 10-trial daily sessions with pentobarbital (10 mg/kg), and to the opposite arm of the maze on other sessions with saline, the drug and saline sessions being alternated. This drug-learning dissociation or state-dependent learning was achieved by rats with medial septal lesions, abolishing hippocampal theta activity, as efficiently as rats with cortical lesions and intact rats. The suggested relationship between drug-learning dissociation and the suppression of hippocampal theta waves, produced by the drug, was not evidenced.

Several clinical aspects of thalamic pulvinotomy

Several clinical aspects of thalamic pulvinotomy were investigated. Influence of electrical stimulation of pulvinar on consciousness, speech, memory, evoked response, emotion, intelligence, character, ophthalmic and auditory examinations were studied during operation and compared between pre-, post, and during operation.