Neurosclence Letters, 89 (1988) 69-73 69 Elsewer Scientific Pubhshers Ireland Ltd NSL 05352 Antagonist action of imidazobenzodiazepine Ro 15-4513 on ethanol-induced alterations of saccadic eye movements in the pigmented rat Ferdmando Rossl, Leonardo Chelazzl, Flhppo Tempm and Plerglorglo Strata Department of Human Anatomy and Phystology, Sectzon of Neurophyswlogy, Umverslty of Turm, Turin (ltalv) (Recewed 21 January 1988, Rewsed versmn received 22 February 1988, Accepted 22 February 1988) Key words Ethanol, lmldazobenzodmzepmeRo 15-4513, Saccadlc eye movement, Pigmented rat FoUowmg an lntrapentoneal mjechon of ethanol (1 g/kg), spontaneous saccades performed by pig- mented rats showed a backward post-saccadlc drift which was sUllpresent 45 mm after the administration When 5 mg/kg of Ro 15-4513 were rejected, 15 mm after ethanol, there was an lmmedmte remarkable reduction m post-saccadlc drift amphtude, with a full recovery in about 30 mm after Ro 15-4513admmls- trauon This drug Is thus able to reverse the effect of ethanol and to restore effectwely a mechamsm of motor mtegratmn Ro 15-4513 IS a newly synthesized lmldazobenzodlazeplne (Hoffman-La Roche), which has been shown to antagonize the effects of ethanol on the central nervous system [1] In in vitro experiments, Suzdak et al [8] observed that Ro 15-4513 anta- gonized ethanol stimulated 36C1- uptake into isolated brain vesicles Electrophysiolo- glcal studies in VlVO showed that Ro 15-4513 is able to reverse the depressant effect of ethanol on ;,-motoneurones discharge [7] At the behavloural level, different tests hke the 'horizontal wire test' [1], the 'holeboard test' [4] and other tests [8] (see also ref 4 for a review) demonstrated the abihty of Ro 15-4513 to reduce the effects of acute ethanol intoxication Nevertheless, there are still some discrepancies about the efficacy of Ro 15-4513 m countering every single behavloural disturbance Induced by ethanol Moreover, it is not clear whether this drug ts capable of completely reversing the ethanol reduced alterations [4] This paper is aimed at describing how ethanol may affect some aspects of eye movements and how Ro 15-4513 may interact with ethanol Eye movements repre- Correspondence F Ross1,Department of Human Anatomy and Physiology, Section of Neurophyslology, Corso Raffaello 30, 10125 Tonno, Italy 0304-3940/88/$ 03 50 O 1988 ElsevierSoenhfic Pubhshers Ireland Ltd