Enduring amnesia induced by ICV scopolamine is reversed by sesame oil in male rats

ABSTRACT PURPOSE: To evaluated the long-term effect of scopolamine and sesame oil on spatial memory. METHODS: Memory impairment induced by Intracerebroventricular (ICV) injection of scopolamine hydrochloride (10 μg/ rat). Animals were gavaged for 4 weeks with saline, sesame oil (0.5, 1, or 2 mL/kg/day), or 3 weeks with memantine (30 mg/kg/day) in advance to induction of amnesia. Morris water maze (MWM) test was conducted 6 days after microinjection of scopolamine. Then, blood and brain samples were collected and evaluated for the malondialdehyde (MDA) levels, superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities, and total antioxidant status (TAS) and ferric reducing ability of plasma (FRAP). RESULTS: Scopolamine significantly decreased traveled distance and time spent in target quadrant in probe test. Pretreatment of rats with sesame oil (0.5 mg/kg) mitigated scopolamine-induced behavioral alterations. Measurement of MDA, SOD, and GPX in brain tissue, and FRAP and TAS in blood showed little changes in animals which had received scopolamine or sesame oil. CONCLUSIONS: Intracerebroventricular injection of scopolamine has a residual effect on memory after six days. Sesame oil has an improving effect on spatial memory; however this effect is possibly mediated by mechanisms other than antioxidant effect of sesame oil.

Effect of alpha-7 nicotinic acetylcholine receptor activation on beta-amyloid induced recognition memory impairment. Possible role of neurovascular function

PURPOSE: To evaluate the effects of PHA-543613 (α7-nAChR agonist) and galantamine (acetylcholinesterase inhibitor (AChEI)) on recognition memory and neurovascular coupling (NVC) response in beta-amyloid (Aβ) 25-35-treated mice. METHODS: PHA-543613 (1 mg/kg, i.p.), and galantamine (3 mg/kg, s.c.), effects were tested in Aβ25-35 mice model of AD. α7-nAChR antagonist, methyllycaconitine (MLA) (1 mg/kg, i.p.), was used for evaluation of receptor blockade effects. Recognition memory in animals was assessed by the novel object recognition (NOR) task. NVC response was analyzed by laser-doppler flow meter in barrel cortex by whisker stimulation method. RESULTS: Both, PHA-543613 and galantamine improve recognition memory in Aβ-treated animals. However, the advantageous effects of PHA-543613 were significantly higher than galantamine. Also, pretreatment with MLA reversed both galantamine and PHA-543613 effects on NOR. Impaired NVC response in AD animals was improved by PHA-543613 and galantamine. However, MLA pretreatment disrupts this function. CONCLUSION: Activation of α7-nAChR improved recognition memory possible through enhancement of neurovascular response in Alzheimer's disease in animals.