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Your search keyword '"Deadwyler, Samuel A."' showing total 20 results
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20 results on '"Deadwyler, Samuel A."'

16. Multiple Neuron Recording in the Hippocampus of Freely Moving Animals

Author

BOWMAN GRAY SCHOOL OF MEDICINE WINSTON-SALEM NC, Deadwyler, Samuel A., BOWMAN GRAY SCHOOL OF MEDICINE WINSTON-SALEM NC, and Deadwyler, Samuel A.

Abstract

Progress over the last year on the development of multineuronal recording systems has been significant. Since this was one of the main objectives of the consortium of three laboratories it has been a principle focus of the past years research efforts. This phase is near completion and currently being implemented in several research projects. Consequently most of the research effort in the past year has been directed toward these technological accomplishments. However in addition to the strides made in bringing the multineurone and multi-tasking computer systems to completion, several studies which were in preliminary stages at the time of submission are now near completion, several studies which were in preliminary stages at the time of submission are now near completion and are being prepared for publication. Specifically, these include the signal detection task and the DMTS task in which complex neurophysiological analyses have revealed striking new relationships to sensory processing strategies in the hippocampus and cortex. The accompanying report summarizes these and other accomplishments in the first year of the award.

Published
1990

17. Restoring Lost Cognitive Function.

Author

Berger, Theodore W., Ahuja, Ashish, Courellis, Spiros H., Deadwyler, Samuel A., Erinjippurath, Gopal, Gerhardt, Gregory A., Gholmieh, Ghassan, Granacki, John J., Hampson, Robert, Min Chi Hsaio, Lacoss, Jeffrey, Marmarelis, Vasilis Z., Nasiatka, Patrick, Srinivasan, Vijay, Song, Dong, Tanguay, Armand R., and Wills, Jack

Subjects
COGNITION disorders, ARTIFICIAL organs, CEREBRAL cortex, PROSTHETICS, BIOMIMETIC chemicals, ARTIFICIAL implants, MEDICAL equipment, BIOMEDICAL materials
Abstract

Reports on the development of a hippocampal-cortical neural prostheses by researchers from the U.S. Use of the novel medical apparatus to restore lost cognitive function; Safety and efficacy of replacing the CA3 region of the hippocampal slice with the biomimetic device; Characterization and mathematical modeling of the nonlinear dynamic properties of the region.

Published
2005
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20. Hippocampal Gαq/11 but not Gαo-coupled receptors are altered in aging.

Author

McQuail, Joseph A., Davis, Kathleen N., Miller, Frances, Hampson, Robert E., Deadwyler, Samuel A., Howlett, Allyn C., and Nicolle, Michelle M.

Subjects
*HIPPOCAMPUS (Brain), *G protein coupled receptors, *AGING, *NEUROPLASTICITY, *LABORATORY rats, *OXOTREMORINE
Abstract

Abstract: Normal aging may limit the signaling efficacy of certain GPCRs by disturbing the function of specific Gα-subunits and leading to deficient modulation of intracellular functions that subserve synaptic plasticity, learning and memory. Evidence suggests that Gαq/11 is more sensitive to the effects of aging relative to other Gα-subunits, including Gαo. To test this hypothesis, the functionality of Gαq/11 and Gαo were compared in the hippocampus of young (6 months) and aged (24 months) F344 × BNF1 hybrid rats assessed for spatial learning ability. Basal GTPγS-binding to Gαq/11 was significantly elevated in aged rats relative to young and but not reliably associated with spatial learning. mAChR stimulation of Gαq/11 with oxotremorine-M produced equivocal GTPγS-binding between age groups although values tended to be lower in the aged hippocampus and were inversely related to basal activity. Downstream Gαq/11 function was measured in hippocampal subregion CA1 by determining changes in [Ca2+]i after mAChR and mGluR (DHPG) stimulation. mAChR-stimulated peak change in [Ca2+]i was lower in aged CA1 relative to young while mGluR-mediated integrated [Ca2+]i responses tended to be larger in aged. GPCR modulation of [Ca2+]i was observed to depend on intracellular stores to a greater degree in aged than young. In contrast, measures of Gαo-mediated GTPγS-binding were stable across age, including basal, mAChR-, GABABR (baclofen)-stimulated levels. Overall, the data indicate that aging selectively modulates the activity of Gαq/11 within the hippocampus leading to deficient modulation of [Ca2+]i following stimulation of mAChRs but these changes are not related to spatial learning. [Copyright &y& Elsevier]

Published
2013
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