Journal article
GABAergic modulation of the analgesic effects of morphine microinjected in the ventral periaqueductal gray matter of the rat
Brain research, Vol.436(2), pp.223-228
1987
Handle:
https://hdl.handle.net/2376/103825
PMID: 3435824
Abstract
The possibility that GABAergic neurons in the ventral periaqueductal gray matter modulate the analgesic effects of morphine microinjected into this brain area was investigated in the rat. Microinjection of 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin 3-ol (THIP) (0.4 μg in 0.2 μl), a GABA agonist, in the ventral periaqueductal gray matter significantly reversed the increase of tail-flick latency induced by a prior injection of morphine sulfate (4 μg in 0.2 μl) at the same site. Conversely, microinjection in the same region of picrotoxin (10 ng in 0.2 μl), a GABA antagonist, significantly potentiated the analgesic effect of the same dose of morphine. These results suggest the existence of GABAergic neurons that tonically inhibit periaqueductal gray output neurons involved in centrifugal pain inhibition. The analgesic effects of opiates may, at least in part, result from disinhibition of these GABAergic neurons.
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Details
- Title
- GABAergic modulation of the analgesic effects of morphine microinjected in the ventral periaqueductal gray matter of the rat
- Creators
- Antoine DepaulisMichael M MorganJohn C Liebeskind
- Publication Details
- Brain research, Vol.436(2), pp.223-228
- Academic Unit
- Psychology, Department of
- Publisher
- Elsevier B.V
- Identifiers
- 99900546517801842
- Language
- English
- Resource Type
- Journal article