ABSTRACT
<p><b>OBJECTIVE</b>To observe the effect of orexin-A on the recovery and cognitive function of aged rats after ketamine anesthesia.</p><p><b>METHODS</b>Fifty-five aged rats were divided randomly into control group, model control group, 1 nmol/L Orexin-A group, and 4 nmol/L Orexin-A group. In the latter 3 groups, the rats received an intraperitoneal injection of ketamine at 100 mg/kg, and normal saline was injected in the control group. Ten minutes after the injections, the rats received intraventricular injections of artificial cerebrospinal fluid (control and model control group) or of 10 microl 1 or 4 nmol/L Orexin-A as indicated. The behavioral changes of the rats were assessed by the duration of loss of righting reflex (LORR). Electroencephalogram (EEG) recordings were used to evaluate the changes in rat brain activity by comparison of the percent of sigma wave in EEG before and after the intraventricular injections. Morris water maze was used to test the learning and spatial localization abilities of the rats.</p><p><b>RESULTS</b>Ketamine resulted in obvious impairment of learning and memory abilities of the aged rats. Orexin-A at 4 nmol/L induced significant decrease in the duration of LORR and marked reduction of sigma activities in anesthetic rats (P<0.05), and obviously improved the learning and spatial localization abilities of the rats after anesthesia (P<0.05).</p><p><b>CONCLUSION</b>Orexin-A can promote the recovery and improve the cognitive function of aged rats after ketamine anesthesia.</p>
Subject(s)
Animals , Male , Rats , Aging , Anesthesia Recovery Period , Anesthetics, Dissociative , Cognition , Delayed Emergence from Anesthesia , Intracellular Signaling Peptides and Proteins , Pharmacology , Ketamine , Neuropeptides , Pharmacology , Orexins , Random Allocation , Rats, Sprague-DawleyABSTRACT
@#Objective To observe the effect of transcranial low frequency electrical stimulation on the contents of monoamines in ischemic area of rats with middle cerebral artery occlusion(MCAO).MethodsPermanent MCAO model of Wistar rat was established with silk thread enveloped with polyammoniacum.The ischemic areas received various intensity of transcranial low frequency electrical stimulation for 1 hour in rats underwent 1 hour of ischemia.Then the affected tissue was processed with fluorospectrophotometry to determine the contents of dopamine(DA),noradrenalin(NE) and 5-hydroxytryptamine(5-HT).ResultsCompared with the sham-operation group,the contents of DA,NE and 5-HT in ischemic area of MCAO model rats decreased obviously(all P<0.01),while all three monoamines investigated in the sham-operation group with transcranial low frequency electrical stimulation had no significant change.In the MCAO groups stimulating with lower(10 V) and middle(30 V) intensity transcranial low frequency electrical field,the contents of DA,NE and 5-HT in ischemic area had no significant increase.But in the MCAO group stimulating with high(50 V) intensity transcranial low frequency electrical field,the contents of DA,NE and 5-HT in ischemic area increased significantly(P<0.05).ConclusionSome degree of intensity transcranial low frequency electrical field stimulation can increase the contents of DA,NE and 5-HT in ischemic area of rats subjected to MCAO.