OBJECTIVES: To assess the regulatory effect of cannabidiol (CBD) on circadian rhythm sleep disorders following general anesthesia and explore its potential mechanism in a rat model of propofol-induced rhythm sleep disorder. METHODS: An electrode was embedded in the skull for cortical EEG recording in 24 male SD rats, which were randomized into control, propofol, CBD treatment, and diazepam treatment groups (n=6). Eight days later, a single dose of propofol (10 mg/kg) was injected via the tail vein with anesthesia maintenance for 3 h in the latter 3 groups, and daily treatment with saline, CBD or diazepam was administered via gavage; the control rats received only saline injection. A wireless system was used for collecting EEG, EMG, and body temperature data within 72 h after propofol injection. After data collection, blood samples and hypothalamic tissue samples were collected for determining serum levels of oxidative stress markers and hypothalamic expressions of the key clock proteins. RESULTS: Compared with the control rats, the rats with CBD treatment showed significantly increased sleep time at night (20:00-6:00), especially during the time period of 4:00-6:00 am. Compared with the rats in propofol group, which had prolonged SWS time and increased sleep episodes during 18:00-24:00 and sleep-wake transitions, the CBD-treated rats exhibited a significant reduction of SWS time and fewer SWS-to-active-awake transitions with increased SWS aspects and sleep-wake transitions at night (24:00-08:00). Diazepam treatment produced similar effect to CBD but with a weaker effect on sleep-wake transitions. Propofol caused significant changes in protein expressions and redox state, which were effectively reversed by CBD treatment. CONCLUSIONS CBD can improve sleep structure and circadian rhythm in rats with propofol-induced sleep disorder possibly by regulating hypothalamic expressions of the key circadian clock proteins, suggesting a new treatment option for perioperative sleep disorders.
Animals ; Rats, Sprague-Dawley ; Male ; Cannabidiol/therapeutic use* ; Rats ; Circadian Rhythm/drug effects* ; Propofol/adverse effects* ; Anesthesia, General/adverse effects* ; Sleep Wake Disorders/chemically induced* ; Hypothalamus/metabolism* ; Electroencephalography

OBJECTIVE To investigate the effect of Jiawei Tianwang Buxin Dan(JWBXD)on insomnia in rats exposed to simulated high-altitude conditions.METHODS ① Thirty SD rats were randomly divided into the normal control,model,model+Jiawei Tianwang Buxin Dan(JWBXD,9.6 mg·kg-1),model+Tianwang Buxin Dan(TWBXD,9.6 mg·kg-1),and model+diazepam(DZP,3 mg·kg-1)groups.Rats,except for the normal control group,were subjected to a low-pressure,low-oxygen animal experimental chamber simulating a 5000 m altitude.Respective drugs were ig administrated once daily at 9:00 for seven days,and signal acquisition and sleep analysis were conducted by a wireless physiological sig-nal telemetry system.②Forty rats were randomly divided into five groups as described in ①.Through-out the experiment,the general condition and body mass of the rats were observed daily.Drug adminis-tration lasted for seven days,and grip strength was tested one hour after the final administration.ELISA was used to measure the levels of corticotropin-releasing hormone(CRH),adrenocorticotropic hor-mone(ACTH),corticosterone(CORT),and melatonin(MLT)in serum.Western blotting was performed to measure the expression levels of core clock proteins period circadian regulator 2(Per2),circadian locomotor output cycles(Clock),cryptochrome 2(Cry2),brain-muscle arnt-like protein 1(Bmal1),nuclear receptor subfamily 1,group D member 1(NR1D1),glycogen synthase kinase-3β(GSK-3β),as well as acetylserotonin O-methyltransferase(ASMT)in the hypothalamus and pineal gland,respectively.RESULTS ① Compared with the normal control group,the model group exhibited a decrease in total sleep time(P<0.01),an increase in wakefulness(P<0.01),a significant reduction in slow wave sleep(SWS)(P<0.05)and the mean bouts duration(P<0.05).Compared with the model group,both DZP and JWBXD(P<0.01)prolonged sleep time and suppressed wakefulness(P<0.01)in the hypoxic envi-ronment.DZP and JWBXD prolonged SWS(P<0.05,P<0.01),while TWBXD had no significant effect.JWBXD improved the mean bouts duration of SWS in the model rats(P<0.01),whereas no such improvement was observed in model+DZP and model+TWBXD groups.② Compared with the normal control group,the model group showed a significant decrease in forelimb grip strength(P<0.01),increased levels of serum ACTH(P<0.05),CRH,and CORT(P<0.01),and decreased MLT levels(P<0.05).The expression levels of Per2,Cry2,GSK-3β,and NR1D1 in the hypothalamus were downregu-lated(P<0.05,P<0.01),while Bmal1 and Clock were upregulated(P<0.05,P<0.01).ASMT expression in the pineal gland was decreased(P<0.05).Compared with the model group,JWBXD and TWBXD enhanced forelimb grip strength(P<0.01),reduced serum CORT and ACTH levels(P<0.05),decreased CRH levels(P<0.01),and restored MLT levels(P<0.01).JWBXD upregulated the expression levels of Per2,Cry2,GSK-3β and NR1D1 in the hypothalamus(P<0.05,P<0.01),but downregulated Bmal1 and Clock expression(P<0.05,P<0.01).TWBXD downregulated Bmal1 expression in the hypothalamus(P<0.01)and increased NR1D1 expression(P<0.05).DZP significantly enhanced the expression levels of Per2,Cry2 and NR1D1 in the hypothalamus(P<0.01).JWBXD,TWBXD and DZP improved ASMT expression in the pineal gland(P<0.05).CONCLUSION JWBXD can improve sleep structure and prolong the duration of SWS in rats exposed to simulated high-altitude conditions.The mechanisms may involve the regulation of core clock protein expressions in the hypothalamus,promotion of mela-tonin secretion,and inhibition of HPA axis hyperactivity.

Objective:To explore the difference in neurotransmitter levels between persons who had been comatose after a brain injury and healthy counterparts, and to explore the relationship between neurotransmitters and different states of consciousness.Methods:A total of 52 persons with brain injury were analyzed retrospectively and divided into a coma group of 30 with Glasgow coma scale scores ≤9 and a sober group of 22 with scores >9. γ-GABA, 5-hydroxytryptamine, noradrenaline and dopamine levels were measured using encephalofluctuography and compared between the two groups.Results:The levels of all of the neurotransmitters tested were significantly lower in the coma group than in the sober group. There were, however, no significant differences between the two groups in terms of relative levels of the neurorsmters. Logistic regression showed that dopamine deficiency is an important risk factor for coma after a brain injury.Conclusions:Most neurotransmitters decrease significantly among those comatose after a brain injury. Dopamine deficiency seems to be a risk factor for the incidence of coma. Therefore, drugs or rehabilitation therapies which can improve dopamine levels can be considered to help coma patients regain consciousness.