جستجوی مقالات مرتبط با کلیدواژه "مکامیلامین" در نشریات گروه "پزشکی"

Nitric oxide and mecamylamine have an important role in anxiety-like behavior. Determining the site of action in the brain and interaction between these agents need to be investigated. Therefore، this study aimed to investigate the possible interaction between mecamylamine and nitric oxide in dorsal hippocampus using the elevated plus-maze test of anxiety. This experimental study was performed on 180 male NMRI mice. Mice were anaesthetized with ketamine and xylazine and two cannuale were inserted stereotaxically into the CA1 region of the dorsal hippocampus. All animals were allowed to recover for 1 week before the beginning of the behavioral testing. The elevated plus-maze was used to test the anxiety-like behavior. Bilateral intra-dorsal hippocampal injections of mecamylamine، L-arginine or L-NAME induced the anxiogenic effects. Intra-dorsal hippocampal injection of ineffective dose of mecamylamine before different doses of L-arginine or L-NAME potentiated the anxiogenic effects of L-arginine or L-NAME. Results reveal that both nitric oxide and mecamylamine not only play a part in the modulation of anxiety in the dorsal hippocampus of mouse but also have demonstrated a complex interaction as well.

β-carbolines alkaloids suchv as harmane have been found in common plant-derived foodstuffs (wheat, rice, corn, barley, grape and mushrooms). These alkaloids have many cognitive effects including alteration short and long term memory. In the present study, the effect of intra-CA1 injection of the nicotinic receptor antagonist mecamylamine on amnesia induced by harmane was examined in mice. Mice were bilaterally implanted with chronic cannulae in the CA1 regions of the dorsal hippocampus. One week after cannulae implantation, mice were trained in a step-down type inhibitory avoidance task, and were tested 24 h after training to measure step-down latency as a scale of memory. Pre-training or post-training systemic injection of harmane induced amnesia. Pre-testing intra-dorsal hippocampus administration of the high dose of nicotinic receptor antagonist, mecamylamine (4 µg/mice) also induced amnesia. On the other hand, pre-test intra-CA1 injection of ineffective doses of mecamylamine (0.5, 1 and 2 µg/mice) fully restored harmane induced amnesia. The present finding in this study indicated that a complex interaction exists between nicotinic receptor of dorsal hippocampus and amnesia induced by Harmane.

Cannabinoid exerts have widespread and complex effects on higher cognitive functions. An overlapping distribution of nicotinic receptors with cannabinoid receptors has been reported in some brain structures such as dorsal hippocampus, thus the functional interactions between cannabinoid and nicotinic systems in cognitive control seems possible. In the present study, the effects of mecamylamine on WIN55, 212-2 induced state-dependent learning was examined. In this experimental study, 280 adult male NMRI mice were esthetized and, then, were cannulae implanted bilaterally in the CA1 regions of the dorsal hippocampus using stereotaxic method. Seven days after the recovery from surgery, behavioral testing was started in inhibitory avoidance task. The animals were trained in a step- down type inhibitory avoidance task and tested 24h after training to measure the step- down latency for the assessment of memory retention. All experiments were conducted in accordance with "standard ethical guidelines for animal care and use". Post-training administration of WIN55, 212-2 and AM251 decreased the memory retrieval. The memory impairment induced by WIN55, 212-2 was completely reversed by pre-test administration of WIN55, 212-2 and/or mecamylamine, suggesting WIN55, 212-2 induced state-dependent memory. These results suggest that nicotinic receptors of the dorsal hippocampal may play an important role in Win55,212-2-induced amnesia and WIN55,212-2 state-dependent memory.