article
The elevated T-maze task as an animal model to simultaneously investigate the effects of drugs on long-term memory and anxiety in mice
Registro en:
0361-9230
Autor
Soares, Bruno Lobão
Asth, Laila
André, Eunice
Soares, Vanessa de Paula
Gavioli, Elaine Cristina
Resumen
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 300 s. 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 2 mg/kg) and the amnestic biperiden (BPR;
0.5, 1 or 3 mg/kg) were injected at three distinct times: pre-training, post-training, and pre-test. Pretraining
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.