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Biomedical subjects

M C Diamond

Publications and source records attributed to M C Diamond.

At least 55 records · Page 3Linked to original sources
PubMed1980

Environmental influences on serotonin and cyclic nucleotides in rat cerebral cortex.

The response to different environmental conditions and negative air ions was investigated on cerebral cortical serotonin and cyclic nucleotides. The results indicated that negative air ions alter the weight of the cerebral cortex and that concentrations of serotonin and cyclic nucleotides can be altered both by different environments and by negative air ions. The data stress the importance of the role of the environment when studying the structure and chemistry of the cerebral cortex.

Animals↗
PubMed1976

Effects of environment on morphology of rat cerebral cortex and hippocampus.

Cortical depth differences were found between male rats exposed to enriched or impoverished environmental conditions for successively shorter times, i.e., for 15 days (from 25 to 40 days of age), for seven days (25 to 32 days of age), and for four days (26 to 30 or 60 to 64 days of age). If the experiments began at weaning (at 25 days of age), the cortical depth changes were caused primarily by impoverishment. If the animals were young adults (60 days of age), upon entering their respective conditions, the cortical changes were induced by enrichment. No cortical depth differences were found between enriched and impoverished rats after one day of differential experience, from 60 to 61 days of age. In every age group and for every duration, except for the one day group, the dorsal-medial segment of the occipital cortex responded to the environmental conditions. No significant hippocampal depth differences were noted between enriched and impoverished animals.

Age Factors↗
PubMed1975

Differences in occipital cortical synapses from environmentally enriched, impoverished, and standard colony rats.

Initial and replication experiments were studied with littermate, S1, male rats 25-55 days of age placed in enriched (EC), standard colony (SC), and impoverished (IC) environments. Measurements of the length of postsynaptic thickenings were taken from asymmetrical axodendritic synapses in layer IV of the dorsal medial occipital cortex. This experiment differed from others of this nature, for animals from both experimental conditions were compared with the standard colony animals. The 8% (p less than 0.01) difference in postsynaptic thickening length between 675 synapses from EC and 680 synapses from IC was primarily due to the IC, as can be seen by comparing both with the SC. The number of synapses per unit area of neuropil was 15% (p less than 0.01) more in the IC than in the EC and this difference was primarily due to impoverishment. Both the original and the replication experiment verified this direction of change. Thus, environmental experience does significantly affect synaptic length and number, although the large magnitude previously reported by Mphillgaard et al. (1971) was not confirmed in the present experiments. The 7% cortical depth difference between the enriched and impoverished animals was seen to be attributed to both conditions when each was compared with the standard colony rats. The plasticity of synaptic dimensions is discussed in relation to our previous work and to work of others.

Animals↗