CHRONIC CAFFEINE'S EFFECTS ON BEHAVIOURAL CHANGES IN STREPTOZOTOCIN-INDUCED DIABETIC RATS

Memory deficits, anxiety and depression are often associated with diabetes, worsening diabetic patients' prognosis. Caffeine, a worldwide used psychoactive substance, is a candidate for improving these conditions.

The aim of this study was to assess the behaviour in streptozotocin-induced diabetic Wistar rats and to evaluate the behavioural effects of caffeine administration.

Diabetes was induced by a single intraperitoneal injection of 50 mg/kg BW streptozotocin (n=10), while control rats received the vehicle (n=9). After six weeks, behavioural tests for anxiety, memory and depression were performed: elevated plus maze (EPM) test, novel object recognition (NOR) test and forced swimming test (FST), respectively. The tests were repeated after further 2 weeks of continuous caffeine administration (20 mg/kg BW/day in drinking water).

Diabetic rats manifested a high anxiety level, showed by a reduced exploratory activity compared to control rats (p<0.05) and long-term memory impairment, spending more time near the old object in NOR test. Caffeine administered for 2 weeks did not modify glycemic values in either group, and attenuated the behavioural changes observed in the EPM test. Also, in NOR test for long-term memory, caffeine administration induced an increased time spent with the novel object than with the old one in both groups.

Our data suggest that chronic caffeine administration has an anxiolytic effect in diabetic rats and improves long-term memory in both diabetic and control rats.