Involvement of neural substrates in reward and aversion to methamphetamine addiction: Testing the reward comparison hypothesis and the paradoxical effect hypothesis of abused drugs.

Clinical studies of drug addiction focus on the reward impact of abused drugs that produces compulsive drug-seeking behavior and drug dependence. However, a small amount of research has examined the opposite effect of aversion to abused drugs to balance the reward effect for drug taking. An aversive behavioral model of abused drugs in terms of conditioned taste aversion (CTA) was challenged by the reward comparison hypothesis (Grigson, 1997).

Dissociating effects of spatial learning from locomotor activity for ouabain-induced bipolar disorder-like rats.

Whether ouabain, a Na+ - and K+-activated adenosine triphosphatase inhibitor, mimics cognitive impairments that can be dissociated from motor effects in the bipolar disorder-like animal model remains unclear. Ouabain and the vehicle aCSF were microinjected into the left lateral ventricle immediately, after 4h, and after 24h. The results showed that (a) locomotion responses of the Immediate group were significantly decreased compared to those of the aCSF group, particularly the first five minutes.

Effects of lithium and carbamazepine on spatial learning and depressive behavior in a rat model of bipolar disorder induced by ouabain.

Lithium (LiCl) and carbamazepine (CBZ), the common mood stabilizers, are thought to be effective treatments for bipolar disorder. The aim of the present study was to investigate whether LiCl as well as CBZ has similar effects on the bipolar disorder-associated cognitive dysfunctions in rats, particularly the spatial learning and depressive responses. Adult male Wistar rats were administered intracerebroventricularly with 5μl of 10(-3)M ouabain on session 1, and then received an intraperitoneal injection of LiCl or CBZ for 4 sessions (1 session/2days).