The basolateral amygdala dopaminergic system contributes to the improving effect of nicotine on stress-induced memory impairment in rats

Publication date: 30 August 2018 Source:Progress in Neuro-Psychopharmacology and Biological Psychiatry, Volume 86 Author(s): Elnaz Keshavarzian, Zahra Ghasemzadeh, Ameneh Rezayof Stress seems to be an important risk factor in the beginning and continuing stages of cigarette tobacco smoking in humans. Considering that both of nicotine administration and stress exposure affect cognitive functions including memory formation, the aim of the present study was 1) to evaluate the effect of subcutaneous (s.c.) administration of nicotine on memory formation under stress and 2) to assess the possible role of the basolateral amygdala (BLA) dopamine D1 and D2 receptors in the effect of nicotine on stress-induced memory retrieval impairment. Adult male wistar rats were bilaterally implanted in the BLA. A step-through type passive avoidance task was used to measure memory retrieval. To induce acute stress, the animals were placed on an elevated platform. The results showed that pre-test exposure to 20 and 30 min stress, but not 10 min, impaired memory retrieval. Nicotine administration (0.05 mg/kg, s.c.) improved stress-induced memory retrieval impairment. The activation of the BLA dopamine receptors via bilateral microinjection of apomorphine (0.025–0.4 μg/rat), a non-selective dopamine receptor agonist, potentiated the effect of nicotine on stress-induced memory retrieval impairment. Interestingly, intra-BLA microinjection of SCH23390 (a selective dopamine D1 receptor ant...

Source: Progress in Neuro Psychopharmacology and Biological Psychiatry - May 18, 2018 Category: Psychiatry Source Type: research