جستجوی مقالات مرتبط با کلیدواژه « سپتوم میانی » در نشریات گروه « پزشکی »

Evidence indicates that morphine impairs memory process. Ghrelin hormone has been linked to learning and memory processes and modulates reward properties of addictive drugs. In this study we examined the role of middle septal ghrelin receptors in the effects of morphine on memory consolidation in passive avoidance learning.

In this experimental study, 91 male Wistar rats were randomly divided into 13 (n=7) groups: saline (1ml/kg), morphine (0.5- 7.5 mg/kg), ghrelin (0- 1 nmol/μl) plus morphine (7.5 mg/kg) or saline (1ml/kg). In ghrelin treated groups animals received intra- medial Septum injection of ghrelin immediately after training and 5 min later saline or morphine was injected subcutaneously. Testing phase was done 24 h after training. Data were analyzed using ANOVA analysis followed by Tukey multiple comparison test. Ethics code: IR.ARAKMU.REC.1397.215

Post-training administration of morphine reduced step-through latency and increased Total dark chamber compared with saline group (p< 0.001). Intra- medial Septum injection of ghrelin inhibited morphine-induced amnesia (p< 0.001). Administration of ghrelin alone had no significant effect on memory retrieval (P > 0.05).

Ghrelin is able to prevent the deleterious effects of morphine on memory and learning in the inhibitory avoidance model and the medial septal region may be involved in this effect.

Many studies have reported the effect of morphine on memory impairment. Evidence suggests that ghrelin enhances memory consolidation. The median septum also has a major role in memory and learning mechanisms. The present study aimed at investigating the role of median septum on the effects of ghrelin in morphine-induced amnesia.

In this experimental research, male Wistar rats were randomly divided into 12 groups: ghrelin groups (0, 0.3, 1.5, 3 nmol/µl) plus saline (1 ml/kg) or morphine (7.5 mg/kg) and groups treated with lidocaine (1 μl/rat) or saline (1 μl/rat) plus ghrelin (3 nmol/μl) or saline (1 μl/rat) plus morphine (7.5 mg/kg). Cannulation was done in the lateral ventricle and median septum. Ghrelin and lidocaine were injected into the lateral ventricle and septum, respectively and morphine was injected subcutaneously. Memory was assessed by avoidant learning.

Post-training intra-ventricle administration of ghrelin 5 min prior to morphine (7.5 mg/kg) prevented morphine amnesia (P= 0.000). Injection of lidocaine into the median septum 5 min before the injection of ghrelin prevented its effect on inhibition of morphine amnesia (P= 0.000).

Injection of ghrelin into the lateral ventricle was found to be capable of preventing morphine-induced memory impairment. Inactivation of the median septum by injection of lidocaine reduced the effect of ghrelin on morphine-induced memory deficits. Therefore, the median septal region appears to mediate the effects of ghrelin on morphine-induced amnesia.