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S G Beck

Publications and source records attributed to S G Beck.

41 records · Page 3Linked to original sources
PubMed1984

Regional differences in binding of [3H]LSD and [3H]5-HT in calf hippocampal slices revealed by radioautography and rapid filtration studies.

Previous radioautographic experiments demonstrated that binding sites labeled by [3H]5-HT and [3H]LSD in rat brain were seen in all layers of CA1, CA4 and the dentate gyrus but not in fields CA2 and CA3 of the hippocampus. In an attempt to confirm this observation we performed binding assays on homogenates from selected areas of calf hippocampus since the small size of the rat hippocampus precluded using preparations from this animal for this purpose. Studies on homogenates from calf hippocampal regions, were done after we determined that the binding to slices in vitro was similar in the calf and rat. Binding of both [3H]5-HT and [3H]LSD by homogenates of CA1 and dentate gyrus, but not of CA3, was saturable. These studies show that the qualitative differences in binding site distribution within the calf hippocampus seen by radioautography reflect quantitative differences in the densities of binding sites revealed by the homogenate studies.

Animals↗
PubMed1983

Cortical evoked potential changes during classical conditioning of morphine dependence in rats.

A classical conditioning experiment was designed to determine if a conditioned neural response would develop and persist in cortical evoked potentials elicited by a foreleg stimulus (CS+) that was paired with morphine administration during the development of dependence and subsequent withdrawal. A stimulus to the other foreleg (CS-) was presented explicitly unpaired with morphine delivery. After dependence was established, the rats were taken from the experimental chamber and withdrawn from morphine for 6 days in their home cages. Finally, during the testing phase, the animals were returned to the experimental chamber and the foreleg stimuli were presented. The CS+ was paired with either morphine or saline injections. Changes due to both morphine effects only and conditioning were observed. The conditioned response, however, was present only in the cortical evoked potentials recorded from those animals receiving contralateral foreleg stimulation as the CS+. The conditioned neural response persisted after withdrawal and was present in both the drug-free and morphine-intoxicated animals. These results provide support for the relapse theory that a nonextinguished conditioned response is retained after withdrawal. However, further experiments are necessary to determine if these conditioned responses can elicit drug-seeking behavior.

Animals↗