Removal of GABAergic inhibition facilitates polysynaptic A fiber-mediated excitatory transmission to the superficial spinal dorsal horn.
Journal Article (Journal Article)
Primary afferent A-fiber stimulation normally evokes fast mono- or polysynaptic EPSCs of short duration. However, in the presence of the GABA(A) receptor antagonist bicuculline, repetitive, long lasting, polysynaptic EPSCs can be observed following the initial, fast response. A-fiber-induced ERK activation is also facilitated in the presence of bicuculline. The frequency of miniature EPSCs and the amplitude of the monosynaptic A-fiber-evoked EPSCs are not affected by bicuculline or the GABA(A) receptor agonist muscimol, suggesting that GABA(A) receptors located on somatodendritic sites of excitatory interneurons are critical for this action. Bicuculline-enhanced polysynaptic EPSCs are completely eliminated by NMDA receptor antagonists APV and ketamine, as was the augmented ERK activation. This NMDA receptor-dependent phenomenon may contribute to bicuculline-induced allodynia or hyperalgesia, as well as the hypersensitivity observed in neuropathic pain patients.
Full Text
Duke Authors
Cited Authors
- Baba, H; Ji, R-R; Kohno, T; Moore, KA; Ataka, T; Wakai, A; Okamoto, M; Woolf, CJ
Published Date
- November 2003
Published In
Volume / Issue
- 24 / 3
Start / End Page
- 818 - 830
PubMed ID
- 14664828
International Standard Serial Number (ISSN)
- 1044-7431
Digital Object Identifier (DOI)
- 10.1016/s1044-7431(03)00236-7
Language
- eng
Conference Location
- United States