Pre-training treatment with scopolamine does not impair memory storage

FORASTIERE N; BOCCIA MM; KRAWCZYK MC; BARATTI CM; BLAKE MG

Huerta Grande, Córdoba

Congreso; XXVIII Congreso Anual de la Sociedad Argentina de Investigación en Neurociencias; 2013

Sociedad Argentina de Investigación en Neurociencias

CF-1 male mice (25-30 g) were trained in an inhibitory avoidance task (IA) using a strong footshock (1.2 mA, 3 sec). They were tested for memory retention 48 hours after training, with latencies at the ceiling (300 sec), and tested several times 24 hours apart to develop extinction of the avoidance memory. Twenty four hours after it mice were tested again, and received a mild footshock (0.4 mA, 1 sec) when stepped in the dark compartment, which reinstate the avoidance memory. Another group of mice received a pre-training injection of scopolamine (SCP, 0.5 mg/kg) and were trained in the IA using the strong footshock. SCP impaired the avoidance memory. Mice were tested 24 hours apart, with progressively reduced latencies, suggesting that extinction was developing, despite the avoidance memory was poorly expressed. At the third retention test, mice received the mild footshock, and were tested again 24 hours after it. The mild footshock reinstate the avoidance memory, to a level similar to control mice. These results suggest that the pretraining administration of SCP did not impair storage of memory, but it remained poorly expressed. This memory developed extinction and was successfully reinstated using a mild footshock. Our results support the notion that SCP did not affect memory storage, but impaired memory expression.