[Behavioral effects of 5-(o-chlorophenyl)-1-methyl-7-nitro-1,3-dihydro-2H-1,4-benzodiazepin-2-one (ID-690)]

Effects on the central nervous system of ID-690, a new benzodiazepine derivative were investigated and compared mainly with those of diazepam in mice and rats. Locomotor activity of the rat was increased with ID-690, at doses of 2 approximately 5 mg/kg p.o., as with diazepam. ID-690 was approximately 5 times more potent than diazepam in inhibiting fighting behavior of long-term isolated mice. Hyperemotionality induced by either septal lesions or olfactory bulbectomy was also inhibited by ID-690. This effect was almost the same in potency as that of diazepam. ID-690 was only 1/30 as potent as diazepam in preventing maximal electroshock convulsion, while it was approximately 18 times more potent that diazepam in suppressing pentetrazol convulsion in mice. ID-690 was approximately 5 times as potent as diazepam in impairing rotarod performance in mice. The muscle relaxant effect of ID-690 was approximately 10 times as potent as diazepam, as measured with an inclined screen test in mice. Thus the effect of ID-690, as compared with diazepam, was characterized by its relatively potent muscle relaxant and extremely potent anti-pentetrazol convulsant action.