Synergic effect of diazepam and muscimol via presynaptic GABAA receptors on glutamatergic evoked EPSCs

Shin, Min Chul; Wakita, Masahito; Xie, Du Jie; Iwata, Satomi; Akaike, Norio

doi:10.1016/j.brainres.2011.07.054

Cited by 13 publications

(3 citation statements)

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“…In the presence of GABA A agonist and antagonist, PPR was enhanced. While not definitive, this suggests a functional presynaptic presence of GABA A receptors [ 25 ]. Secondly, gabazine was able to relieve depression of the second response in a train when recordings were made with intracellular CsF, which inhibits ion flow through postsynaptic GABA A receptors, indicating that postsynaptic GABA A receptors were not shunting the second eEPSC.…”

Section: Discussionmentioning

confidence: 99%

Transient, Activity Dependent Inhibition of Transmitter Release from Low Threshold Afferents Mediated by GABA_AReceptors in Spinal Cord Lamina III/IV

2015

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BackgroundPresynaptic GABAA receptors (GABAARs) located on central terminals of low threshold afferent fibers are thought to be involved in the processing of touch and possibly in the generation of tactile allodynia in chronic pain. These GABAARs mediate primary afferent depolarization (PAD) and modulate transmitter release. The objective of this study was to expand our understanding of the presynaptic inhibitory action of GABA released onto primary afferent central terminals following afferent stimulation.ResultsWe recorded evoked postsynaptic excitatory responses (eEPSCs and eEPSPs) from lamina III/IV neurons in spinal cord slices from juvenile rats (P17–P23, either sex), while stimulating dorsal roots. We investigated time and activity dependent changes in glutamate release from low threshold A fibers and the impact of these changes on excitatory drive. Blockade of GABAARs by gabazine potentiated the second eEPSC during a train of four afferent stimuli in a large subset of synapses. This resulted in a corresponding increase of action potential firing after the second stimulus. The potentiating effect of gabazine was due to inhibition of endogenously activated presynaptic GABAARs, because it was not prevented by the blockade of postsynaptic GABAARs through intracellular perfusion of CsF. Exogenous activation of presynaptic GABAARs by muscimol depressed evoked glutamate release at all synapses and increased paired pulse ratio (PPR).ConclusionsThese observations suggest that afferent driven release of GABA onto low threshold afferent terminals is most effective following the first action potential in a train and serves to suppress the initial strong excitatory drive onto dorsal horn circuitry.

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Section: Discussionmentioning

confidence: 99%

Transient, Activity Dependent Inhibition of Transmitter Release from Low Threshold Afferents Mediated by GABA_AReceptors in Spinal Cord Lamina III/IV

2015

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“…A bipolar stimulating electrode was placed in the Schaffer collateral pathway, and paired stimulation pulses were applied with interpulse intervals of 30, 70, and 200 ms. The population spikes in response to the paired pulse stimulation were recorded extracellularly from the CA1 pyramidal cell layer ( Shin et al, 2011 ) . The stimulation intensity was set to a value which yielded a response of 70–80 % of the maximal amplitude of the population spike.…”

Section: Methodsmentioning

confidence: 99%

“…Inhibition was measured using the paired pulse paradigm and quantified as P2/P1 as a percentage. P 2 is the amplitude of the population spike in response to the second stimulus, and P1 is the amplitude of the population spike in response to the first stimulus ( Shin et al, 2011 ).…”

Section: Methodsmentioning

confidence: 99%

Early-life propofol exposure does not affect later-life GABAergic inhibition, seizure induction, or social behavior

Liu

Lin

Yau

et al. 2023

IBRO Neuroscience Reports

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Effects of halothane on GABAergic and glutamatergic transmission in isolated hippocampal nerve-synapse preparations

Kotani¹,

Wakita

Shin

et al. 2012

Brain Research

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Synergic effect of diazepam and muscimol via presynaptic GABAA receptors on glutamatergic evoked EPSCs

Cited by 13 publications

References 32 publications

Transient, Activity Dependent Inhibition of Transmitter Release from Low Threshold Afferents Mediated by GABA_AReceptors in Spinal Cord Lamina III/IV

Transient, Activity Dependent Inhibition of Transmitter Release from Low Threshold Afferents Mediated by GABA_AReceptors in Spinal Cord Lamina III/IV

Early-life propofol exposure does not affect later-life GABAergic inhibition, seizure induction, or social behavior

Effects of halothane on GABAergic and glutamatergic transmission in isolated hippocampal nerve-synapse preparations

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Synergic effect of diazepam and muscimol via presynaptic GABAA receptors on glutamatergic evoked EPSCs

Cited by 13 publications

References 32 publications

Transient, Activity Dependent Inhibition of Transmitter Release from Low Threshold Afferents Mediated by GABAAReceptors in Spinal Cord Lamina III/IV

Transient, Activity Dependent Inhibition of Transmitter Release from Low Threshold Afferents Mediated by GABAAReceptors in Spinal Cord Lamina III/IV

Early-life propofol exposure does not affect later-life GABAergic inhibition, seizure induction, or social behavior

Effects of halothane on GABAergic and glutamatergic transmission in isolated hippocampal nerve-synapse preparations

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Product

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Transient, Activity Dependent Inhibition of Transmitter Release from Low Threshold Afferents Mediated by GABA_AReceptors in Spinal Cord Lamina III/IV

Transient, Activity Dependent Inhibition of Transmitter Release from Low Threshold Afferents Mediated by GABA_AReceptors in Spinal Cord Lamina III/IV