Abstract
Background: Activation of principal hippocampal neurons is controlled by feedforward and feedback inhibition mediated by γ-aminobutyric acidergic interneurons. The effects of halothane on glutamate receptor-mediated synaptic excitation of inhibitory interneurons have not been reported yet. Methods: The effects of halothane on glutamatergic excitatory postsynaptic currents and on spike threshold in visually identified interneurons were studied with tight-seal, whole-cell voltage- and current-clamp recordings in thin slices from adult mouse hippocampus. The excitatory postsynaptic currents were pharmacologically isolated into their N-methyl-D-aspartate and non-N-methyl-D-aspartate receptor-mediated components using selective antagonists. Results: Halothane (0.37-2.78 mM) reversibly blocked non-N- methyl-D-aspartate and N-methyl-D-aspartate excitatory postsynaptic currents in hippocampal oriens-alveus interneurons. Half-maximal inhibition was observed at similar concentrations (0.59 nM and 0.50 mM, respectively). Halothane inhibited synaptically generated action potentials at concentrations that did not elevate the spike threshold. Conclusions: Halothane blocks glutamate receptor-mediated synaptic activation of inhibitory interneurons in the mouse hippocampus.
Original language | English |
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Pages (from-to) | 1431-1438 |
Number of pages | 8 |
Journal | Anesthesiology |
Volume | 85 |
Issue number | 6 |
DOIs | |
State | Published - 1996 |
Externally published | Yes |
Keywords
- Anesthetics, volatile: halothane
- Animals: mouse
- Brain: hippocampus
- Central nervous system, neuron: interneuron, pyramidal cell
- Central nervous system, receptors: glutamate; N-methyl-D-aspartate, non-N-methyl-D- aspartate
- Central nervous system: excitatory postsynaptic currents
- Measurement technique: hippocampal slice; patchclamp