Ketamine effects on anxiety and fear-related behaviors: Current literature evidence and new findings

Publication date: Available online 23 January 2020Source: Progress in Neuro-Psychopharmacology and Biological PsychiatryAuthor(s): Gabriela P. Silote, Sabrina F.S. de Oliveira, Deidiane E. Ribeiro, Mayara S. Machado, Roberto Andreatini, Sâmia R.L. Joca, Vanessa BeijaminiAbstractKetamine, a non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist, presents a rapid and sustained antidepressant effect in clinical and preclinical studies. Regarding ketamine effects on anxiety, there is a widespread discordance among pre-clinical studies. To address this issue, the present study reviewed the literature (electronic database MEDLINE) to summarize the profile of ketamine effects in animal tests of anxiety/fear. We found that ketamine anxiety/fear-related effects may depend on the anxiety paradigm, schedule of ketamine administration and tested species. Moreover, there was no report of ketamine effects in animal tests of fear related to panic disorder (PD). Based on that finding, we evaluated if treatment with ketamine and another NMDA antagonist, MK-801, would induce acute and sustained (24 hours later) anxiolytic and/or panicolytic-like effects in animals exposed to the elevated T-maze (ETM). The ETM evaluates, in the same animal, conflict-evoked and fear behaviors, which are related, respectively, to generalized anxiety disorder and PD. Male Wistar rats were systemically treated with racemic ketamine (10, 30 and 80 mg/kg) or MK-801 (0.05 and 0.1 mg/kg) and tested in the ETM...
Source: Progress in Neuro Psychopharmacology and Biological Psychiatry - Category: Psychiatry Source Type: research