The effect of lovastatin on cognition impairment induced by bilateral electrical lesion of nucleus basalis magnocellularis in the Alzheimerâs disease model in adult male rats

Background: Statins, inhibitors of 3-hydroxy-3-methyl glutaryl coenzyme A reductase, are widely used as medication to lower cholesterol levels in human patients. Much evidence indicates that statins can also exert neuroprotective actions. So, this study aimed at examining the effect of lovastatin on cognition deficit induced by bilateral electrical lesion of nucleus basalis magnocellularis (NBM) in the Alzheimer’s disease model in adult male rats. Materials and Methods: In this experimental study, 56 adult male wistar rats were divided into 8 groups (n=7): control (intact), NBM lesion group (which received electrically- induced lesion 0.5 mA in 3s), sham group (the electrode was impaled into the NBM with no lesion(, lovastatin groups (lesion+1, 5, 10, 20 mg/kg) and DMSO 5 group (NBM lesion +DMSO 5). Acquisition and retention testing was done by using an eight-radial arm maze in which the patterns of arm entries were recorded for calculating working memory errors, reference memory error and latency in each group. Results: The bilateral NBM lesion resulted in significant reduction of spatial memory in acquisition and retention tests in the form of increased working and reference memory errors compared to the control group (P<0.05). Post-lesion treatment with lovastatin improved the parameters of spatial memory errors in the acquisition and retention tasks compared to the lesion group. Conclusion: The electrical NBM lesion can reduce spatial memory function and the lovastatin therapy after brain injury improved cognitive disorders. It seems that lovastatin by reducing the activity of the acetylcholinesterase enzyme and increasing acetylcholine transferase enzyme activity can cause improvement in learning and memory capability

The Interaction of Cholinergic Muscarinic and Beta-1 Adrenergic Receptors of the CA1 Region in Passive Avoidance Memory Formation in Rat

BACKGROUND AND OBJECTIVE: It is well known that involvement of muscarinic cholinergic and beta noradrenergic systems in process of the memory formation. But, up to now interaction of these systems in the CA1 region of hippocampus is not studied in memory formation. The aim of this study was to investigate the interaction of muscarinic and ?1-adrenergic receptors in the CA1 on memory retrieval. METHODS: In this experimental research, 77 Wistar adult male rats (200-250 g) were used. Animals (in 11 groups) cannulated for CA1 region with stereotaxic surgery and trained in step-through apparatus: saline group (1µl/rat), pilocarpine groups (0.5, 1, 2 µg/rat), betaxolol groups (0.25, 0.5, 1 µg/rat), other four groups included saline/saline, pilocarpine2/saline, pilocarpine2/ betaxolol 0.25, pilocarpine2/ betaxolol 0.5. Drugs injected as intra-CA1 after training and memory tested after 24 hours. The latencies to enter and times spent in dark compartment of apparatus were recording for the evaluation of memory retrieval. FINDINGS: Injection of 2 µg/rat of pilocarpine, a muscarinic receptor agonist, increased the latencies to enter dark compartment (291.4±5.6sec) and decreased the times spent in this compartment (8.6±5.5sec, p<0.05). This effect was reversed by the ineffective low doses of betaxolol (0.25 and 0.5), a ?1-adrenergic receptor antagonist, (p<0.01 and p<0.001 respectively). The latencies to enter dark compartment was 122±47.3 and 62±10.6 sec. Also, the times spent in this compartment was134.6±35.4 and 192±23.2sec respectively.CONCLUSION: It is suggested that enhancement of the inhibitory avoidance memory retrieval, induced by activation of muscarinic cholinergic system of the dorsal hippocampal CA1 region, may be mediated via ?1-adrenergic receptors related mechanisms

The Effects of Intrahippocampus Injection of Almond oil on Passive Avoidance Learning and Memory in Adult Male Rat

Abstract Background & aim: Almond oil contains compounds such asoleic acid, omega 3, 6, 9 polyunsaturated fatty acids and vitamin E. The aim of this study was to investigate the effects of intra-hippocampal injection of almond oil on passive avoidance learning and memory in male rats. Methods: In this experimental study, 56 male rats were randomly divided into 8 groups, including a control, 3 sailin groups which received normal saline 0.5, 1, 2 µl and 4 peanut oil groups which received 5/0, 1, 5/1 and 2 µl of oil.All groups, except the control, Groups except the control group were cannulated with stereotaxic surgery in the left CA1 region. One week after recovery, all groups were trained by shuttle box. Immediately after training, different doses of almond oil and saline were injected through the cannula in CA1 of hippocampus. After 48 hours, their Passive avoidance memory and learning were evaluated. Data were analyzed by ANOVA. Results: Almond oil doses of 0.5,1, 1.5 and 2 µg significantly improved passive avoidance learning and memory (P<0.05), but saline did not have. Conclusion: Almond oil as a steroid, effects on learning and memory and can improve learning and memory. Key Words: Learning, Memory, Almond oil, Hippocampus and Shuttle Bo