Behavioural effects induced by microinjection of L-BOAA into the ventrolateral PAG matter of the mouse

L-BOAA (1 microgram/mouse), microinjected into the ventrolateral periaqueductal gray (PAG) matter, induced a strong reaction of forward avoidance (running) for 20-30 s in 18% of the mice and immobility for 7 +/- 2 min in 72% of the mice from a total of 68 treated animals. Effects were also observed for grooming and clonus in 6% and 4% of the mice, respectively. Duration of L-BOAA-induced immobility was significantly (p < 0.05) reduced by a pretreatment with CNQX (0.5 microgram/mouse), a selective antagonist of AMPA glutamergic subtype receptors, but not by a pretreatment with 2-APV (0.5 microgram/mouse), a selective antagonist of NMDA glutamergic subtype receptors, nor by 2-AP3 (0.5 microgram/mouse), a weak antagonist of metabotropic glutamergic subtype receptors. AMPA (0.05 microgram/mouse), also microinjected into ventrolateral PAG, induced the same pattern of behavioural effects as L-BOAA. Forward avoidance, grooming, and clonus induced by L-BOAA or AMPA were also significantly antagonised by a pretreatment with CNQX (data not shown).