[Reproduction of "passive" avoidance in rats by administering pharmacologic agents]

In experiments on rats learned to passive avoidance reaction in one trial with subsequent administration of electroconvulsive shock (two hours after learning), the influence of different factors on the retrieval of the lost reaction was tested after three days. The greatest restoring capacity was exhibited by a non-specific reminding agent, the bell, gamma-amino-butyric acid (200 mg/kg) and etimizol (1.5 mg/kg). In animals with a preserved reaction, a number of pharmacological agents impaired retrieval of the habit (caffeine 5 mg/kg, carbocholine 0.01 mg/kg and metamizil 0.5 mg/kg). Optimal conditions for the restoration of the lost reaction were formed by etimizol and gamma-aminobutyric acid. Cholinergic mechanisms play a certain role in the functioning of the retrieval apparatus.