About this Neuroscience article

Benzodiazepine tolerance at GABAergic synapses on hippocampal CA1 pyramidal cells by Xu J. Zeng; Elizabeth I. Tietz is a Neuroscience article available to read on EtoBox.

Modulation of GABA function following 1 week oral administration of flurazepam (FZP) was investigated in chloride-loaded, rat hippocampal CA1 pyramidal neurons. Rats were sacrificed 2 or 7 days after ending drug treatment, when anticonvulsant tolerance was present or absent in vivo, respectively. Spontaneous (s)IPSCs and miniature (m)IPSCs were recorded using whole-cell voltage-clamp techniques. s/mIPSCs were bicuculline-sensitive, voltage-dependent, and reversed their polarity at 0 mV, the predicted E Cl -. Comparisons of s/mIPSCs between FZP-treated and control groups were made at V h ϭ -90, -70, and -50 mV. The frequency of sIPSCs, but not mIPSCs, was significantly decreased in FZP-treated neurons 2 days, but not 7 days, after FZP treatment, suggesting a decrease in interneuron activity. These conclusions were supported by the negative findings of additional studies of [ 3 H]GABA release from hippocampal slices and [ 3 H]GABA uptake from hippocampal synaptosomes. The lack of change in the paired-pulse depression of GABA B -mediated IPSPs suggested that autoreceptor function was also not impaired following chronic FZP treatment. A large reduction in both sIPSC and mIPSC amplitude

Author

Xu J. Zeng; Elizabeth I. Tietz

Publisher

John Wiley and Sons; Wiley (John Wiley & Sons); John Wiley & Sons Inc.; Wiley (ISSN 0887-4476)

Published

1999

Language

EN

Field

Neuroscience (Life Sciences)