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Published in: Brain Structure and Function 5/2022

01-06-2022 | Original Article

GABAB receptors constrain glutamate presynaptic release and postsynaptic actions in substantia gelatinosa of rat spinal cord

Authors: Mingwei Zhao, Caifeng Shao, Jiaxue Dong, Qian Chen, Rui Ma, Ping Jiang, Wei-Ning Zhang, Kun Yang

Published in: Brain Structure and Function | Issue 5/2022

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Abstract

The substantia gelatinosa (SG, lamina II of spinal cord gray matter) is pivotal for modulating nociceptive information from the peripheral to the central nervous system. γ-Aminobutyric acid type B receptors (GABABRs), the metabotropic GABA receptor subtype, are widely expressed in pre- and postsynaptic structures of the SG. Activation of GABABRs by exogenous agonists induces both pre- and postsynaptic inhibition. However, the actions of endogenous GABA via presynaptic GABABRs on glutamatergic synapses, and the postsynaptic GABABRs interaction with glutamate, remain elusive. In the present study, first, using in vitro whole-cell recordings and taking minimal stimulation strategies, we found that in rat spinal cord glutamatergic synapses, blockade of presynaptic GABABRs switched “silent” synapses into active ones and increased the probability of glutamate release onto SG neurons; increasing ambient GABA concentration mimicked GABABRs activation on glutamatergic terminals. Next, using holographic photostimulation to uncage glutamate on postsynaptic SG neurons, we found that postsynaptic GABABRs modified glutamate-induced postsynaptic potentials. Taken together, our data identify that endogenous GABA heterosynaptically constrains glutamate release via persistently activating presynaptic GABABRs; and postsynaptically, GABABRs modulate glutamate responses. The results give new clues for endogenous GABA in modulating the nociception circuit of the spinal dorsal horn and shed fresh light on the postsynaptic interaction of glutamate and GABA.
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Literature
go back to reference Bonalume V, Caffino L, Castelnovo LF, Faroni A, Liu S, Hu J, Milanese M, Bonanno G, Sohns K, Hoffmann T, De Col R, Schmelz M, Fumagalli F, Magnaghi V, Carr R (2021) Axonal GABAA stabilizes excitability in unmyelinated sensory axons secondary to NKCC1 activity. J Physiol (lond) 599:4065–4084. https://doi.org/10.1113/JP279664CrossRef Bonalume V, Caffino L, Castelnovo LF, Faroni A, Liu S, Hu J, Milanese M, Bonanno G, Sohns K, Hoffmann T, De Col R, Schmelz M, Fumagalli F, Magnaghi V, Carr R (2021) Axonal GABAA stabilizes excitability in unmyelinated sensory axons secondary to NKCC1 activity. J Physiol (lond) 599:4065–4084. https://​doi.​org/​10.​1113/​JP279664CrossRef
go back to reference Malcangio M, Bowery NG (1993) γ-Aminobutyric acidB, but not γ-aminobutyric acidA receptor activation, inhibits electrically evoked substance P-like immunoreactivity release from the rat spinal cord in vitro. J Pharmacol Exp Ther 266:1490–1496PubMed Malcangio M, Bowery NG (1993) γ-Aminobutyric acidB, but not γ-aminobutyric acidA receptor activation, inhibits electrically evoked substance P-like immunoreactivity release from the rat spinal cord in vitro. J Pharmacol Exp Ther 266:1490–1496PubMed
Metadata
Title
GABAB receptors constrain glutamate presynaptic release and postsynaptic actions in substantia gelatinosa of rat spinal cord
Authors
Mingwei Zhao
Caifeng Shao
Jiaxue Dong
Qian Chen
Rui Ma
Ping Jiang
Wei-Ning Zhang
Kun Yang
Publication date
01-06-2022
Publisher
Springer Berlin Heidelberg
Published in
Brain Structure and Function / Issue 5/2022
Print ISSN: 1863-2653
Electronic ISSN: 1863-2661
DOI
https://doi.org/10.1007/s00429-022-02481-2

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