Agmatine inhibits morphine-induced memory impairment in the mouse step-down inhibitory avoidance task.
The effect of agmatine on memory formation in morphine-treated mice on the step-down inhibitory avoidance test was examined. Pre-training and pre-test administration of agmatine (5, 10 and 20mg/kg, s.c.) facilitated memory formation and retrieval while post-training administration of agmatine (5, 10 and 20mg/kg, s.c.) had no effect on memory consolidation. Idazoxan (5mg/kg, i.p.) inhibited the effect of agmatine on memory formation and retrieval. Pre-training administration of morphine (1.25, 2.5 and 5mg/kg, s.c.) impaired memory formation while post-training and pre-test administration of morphine (1.25, 2.5 and 5mg/kg, s.c.) had no effect on memory consolidation and retrieval. Pre-training agmatine treatment reversed the impairment of morphine on memory formation. Moreover, pre-test administration of agmatine inhibited morphine-induced amnesia. Pre-training and pre-test idazoxan (5mg/kg, i.p.) treatment inhibited the effect of agmatine on morphine induced memory impairment. In conclusion, agmatine inhibited morphine-induced memory impairment on the mice step-down inhibitory avoidance test. The mechanism was exerted, at least in part, through activation of imidazoline receptors.
Lu
Wei
W
Beijing Institute of Pharmacology and Toxicology, 27 Taiping Road, Beijing 100850, China.
Dong
Hua-Jin
HJ
Gong
Zheng-Hua
ZH
Su
Rui-Bin
RB
Li
Jin
J
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000376:Agmatine / Q000494:pharmacology*; D000701:Analgesics, Opioid / Q000037:antagonists & inhibitors* / Q000633:toxicity; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D019329:Idazoxan / Q000494:pharmacology; D054755:Imidazoline Receptors / Q000187:drug effects; D008297:Male; D008569:Memory Disorders / Q000517:prevention & control* / Q000523:psychology; D011939:Mental Recall / Q000187:drug effects; D051379:Mice; D009020:Morphine / Q000037:antagonists & inhibitors* / Q000633:toxicity
D000317:Adrenergic alpha-Antagonists; D000701:Analgesics, Opioid; D054755:Imidazoline Receptors; D000376:Agmatine; D009020:Morphine; D019329:Idazoxan