Involvement of locus coeruleus projections in opiate withdrawal but not in opiate tolerance in mice.
The ability of N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4), a potent and selective noradrenergic neurotoxic compound, to modify morphine tolerance and dependence was investigated in mice DSP-4 pretreatment, either 50 or 100 mg/kg i.p., had no effect on the development of tolerance to the analgesic effect of morphine evaluated by the tail-flick test. On the contrary, the higher dose of DSP-4 prevented repetitive vertical jumping, a major naloxone-precipitated withdrawal symptom in mice. These results demonstrate that coerulean neuronal projections are not necessary for the development of tolerance but are clearly involved in the expression of withdrawal-induced jumping in mice.
Dossin
O
O
Laboratoire de Pharmacologie et Toxicologie Fondamentales, CNRS, Toulouse, France.
Hanoun
N
N
Zajac
J M
JM
D000818:Animals; D001596:Benzylamines / Q000494:pharmacology; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D004361:Drug Tolerance; D008125:Locus Coeruleus / Q000166:cytology / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D051379:Mice; D009020:Morphine / Q000009:adverse effects*; D009476:Neurons, Efferent; D014179:Neurotransmitter Uptake Inhibitors / Q000494:pharmacology; D009638:Norepinephrine / Q000378:metabolism; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology*
D001596:Benzylamines; D014179:Neurotransmitter Uptake Inhibitors; D009020:Morphine; C012102:DSP 4; D004298:Dopamine; D009638:Norepinephrine