Desinhibitory effect of allopregnanolone within the medial prefrontal cortex of male rats on the plus maze test

CASTELLER, G; ; LACONI MYRIAM ; FRAILE, M; LANDA A; CABRERA R; GARGIULO, P.A

International Journal of Neuroprotection and Neurodegeneration

RPA Publications

Lugar: Innsbruck; Año: 2006 vol. 2 p. 120 - 126

1745-1183

The aim of the present paper is to study the behavioural effects of the injection of allopregnenolona a neurosteroid derived from progesterone, on performance in the plus maze test. It was studied in male rats injected into the medial prefrontal cortex. the rats were bilaterally cannulated into the mPFC and were divided into 3 groups and received either injections of vehicle  or Allo (0.06 or 0.6mM)30 min before test. Time spent in open and close arms were recorded. Time spend in the open arm was increased with both doses of Allo and in the same way the time spent in the distal extreme. Time per entry was not modified by treatment. No differences were seen in closed arm entries. We conclude that Allo injection induced a deshinibitory action, with some similarities, but also diferences, with an anxiolytic-like effect. This experimental approach could be globally considered as a model of schizophrenic behavioral deshinibition related to affective flattening. Furthermore, it gives additional evidences in way of understanding epidemiological facts, like the age of presentation of schizofrenia after puberty, and strongly suggests a possible role of neurosteroids in the initial schizophrenic syndrome.