title: Striatal dopamine release and biphasic pattern of locomotor and motor activity under gas narcosis.
abstract: Inert gas narcosis is a neurological syndrome appearing when humans or animals are exposed to hyperbaric inert gases (nitrogen, argon) composed by motor and cognitive impairments. Inert gas narcosis induces a decrease of the dopamine release at the striatum level, structure involved in the regulation of the extrapyramidal motricity. We have investigated, in freely moving rats exposed to different narcotic conditions, the relationship between the locomotor and motor activity and the striatal dopamine release, using respectively a computerized device that enables a quantitative analysis of this behavioural disturbance and voltammetry. The use of 3 MPa of nitrogen, 2 MPa of argon and 0.1 MPa of nitrous oxide, revealed after a transient phase of hyperactivity, a lower level of the locomotor and motor activity, in relation with the decrease of the striatal dopamine release. It is concluded that the striatal dopamine decrease could be related to the decrease of the locomotor and motor hyperactivity, but that other(s) neurotransmitter(s) could be primarily involved in the behavioural motor disturbances induced by narcotics. This biphasic effect could be of major importance for future pharmacological investigations, and motor categorization, on the basic mechanisms of inert gas at pressure.
authors.affiliation: Université de la Méditerranée et IMNSSA, E.A. 3280, Laboratoire de Physiopathologie et Action Thérapeutique des Gaz sous Pression, Faculté de Médecine Nord, IFR Jean Roche, 13916, cedex 20, Marseille, France.
authors.forename: Norbert
authors.initials: N
authors.lastname: Balon
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Risso
authors.forename: François
authors.initials: F
authors.lastname: Blanc
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Rostain
authors.forename: Michel
authors.initials: M
authors.lastname: Weiss
mesh_terms: D000818:Animals; D001128:Argon / Q000494:pharmacology; D001274:Atmospheric Pressure; D003624:Darkness; D004298:Dopamine / Q000378:metabolism*; D004563:Electrochemistry; D004566:Electrodes; D007222:Inert Gas Narcosis; D008027:Light; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D017072:Neostriatum / Q000187:drug effects / Q000378:metabolism*; D009584:Nitrogen / Q000494:pharmacology; D009609:Nitrous Oxide / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013239:Stereotyped Behavior / Q000187:drug effects
chemical_list: D001128:Argon; D009609:Nitrous Oxide; D009584:Nitrogen; D004298:Dopamine