title: The elevated T-maze task as an animal model to simultaneously investigate the effects of drugs on long-term memory and anxiety in mice.
abstract: The elevated T-maze (ETM) is an apparatus derived from the elevated plus-maze test, which is used to evaluate anxiety. Because anxiety is a biasing factor in models of memory, this study proposed the ETM as a task for the simultaneous assessment of memory and anxiety in mice. The ETM consists of one enclosed and two open arms. The procedure is based on the avoidance of open spaces learned during training session, in which mice were exposed to the enclosed arm as many times as needed to stay 300s. In the test session, memory is assessed by re-exposing the mouse to the enclosed arm and the latency to enter an open arm was recorded. The anxiolytic diazepam (DZP; 1 or 2mg/kg) and the amnestic biperiden (BPR; 0.5, 1 or 3mg/kg) were injected at three distinct times: pre-training, post-training, and pre-test. Pre-training administration of BPR 1 and DZP 2 increased the number of trials needed to reach the avoidance criterion, suggesting a passive avoidance learning impairment. However, BPR induced hyperlocomotion, which could bias the interpretation of any BPR-induced effects during the training session. Pre-training injection of BPR did not affect the spontaneous increase in the latency to enter an open arm between trials, while DZP reduced latencies in the first three trials suggesting anxiolysis. In the test session, pre-training injection of BPR 1 and DZP 2 reduced latencies to enter an open arm, indicating memory impairment. Post-training and pre-test injection of DZP or BPR did not affect memory. In conclusion, the proposed ETM task is practical for the detection of the anxiolytic and amnesic effects of drugs.
authors.affiliation: Behavioral Pharmacology Laboratory, Department of Biophysics and Pharmacology, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
authors.forename: Laila
authors.initials: L
authors.lastname: Asth
authors.forename: Bruno
authors.initials: B
authors.lastname: Lobão-Soares
authors.forename: Eunice
authors.initials: E
authors.lastname: André
authors.forename: Vanessa de Paula
authors.initials: Vde P
authors.lastname: Soares
authors.forename: Elaine Cristina
authors.initials: EC
authors.lastname: Gavioli
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D014151:Anti-Anxiety Agents / Q000627:therapeutic use*; D001007:Anxiety / Q000188:drug therapy* / Q000503:physiopathology*; D001712:Biperiden / Q000494:pharmacology / Q000627:therapeutic use; D003975:Diazepam / Q000494:pharmacology / Q000627:therapeutic use; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005106:Exploratory Behavior / Q000187:drug effects; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D057567:Memory, Long-Term / Q000187:drug effects*; D051379:Mice; D011897:Random Allocation; D013997:Time Factors
chemical_list: D014151:Anti-Anxiety Agents; D001712:Biperiden; D003975:Diazepam