[Action mechanism of anticonvulsant and anti-immobility (forced swim) effects of 3', 4'-dihydro-N, N-dimethylspiro-[9H-fluorene-9, 2' (5'H) furane]-3'-methanamine (AE37F)].

AE37F, a new aminotetrahydrofuranic derivative, exhibited, at 10-30 mg/Kg (po) or 1-10 mg/Kg (ip), antagonism of tonic convulsions, induced by pentetrazole (130 mg/Kg, ip), and of forced swin immobility, in mice. At these doses AE37F induced a considerable (100-250%) increase of serotonin (5-HT) and its main metabolite, 5-hydroxyindolacetic acid (5-HIAA), in the rat nucleus reticularis pontis oralis (NRPO), antagonized by amantadine, which also increased 5-HT and 5-HIAA levels in the NRPO. It is suggested: a) that the anti-immobility effect of AE37F is related to its antimuscarinic properties, b) that the rate of 5-HT release in the NRPO, calculated here by a new approach (from the 5-HT and 5-HIAA brain levels) is increased by AE37F and decreased by amantadine, in the NRPO, c) that the anti-convulsant action, observed with AE37F, could be related to a NMDA-sigma mediated stimulation of serotoninergic, GABAergic and glycinergic brain neurones, antagonized by the NMDA-sigma inhibition induced by amantadine.