Endocannabinoid signaling in hypothalamic circuits regulates arousal from general anesthesia in mice.

Consciousness can be defined by two major attributes: awareness of environment and self, and arousal, which reflects the level of awareness. The return of arousal after general anesthesia presents an experimental tool for probing the neural mechanisms that control consciousness. Here we have identified that systemic or intracerebral injection of the cannabinoid CB1 receptor (CB1R) antagonist AM281 into the dorsomedial nucleus of the hypothalamus (DMH) - but not the adjacent perifornical area (Pef) or the ventrolateral preoptic nucleus of the hypothalamus (VLPO) - accelerates arousal in mice recovering from general anesthesia. Anesthetics selectively activated endocannabinoid (eCB) signaling at DMH glutamatergic but not GABAergic synapses, leading to suppression of both glutamatergic DMH-Pef and GABAergic DMH-VLPO projections. Deletion of CB1R from widespread cerebral cortical or prefrontal cortical (PFC) glutamatergic neurons, including those innervating the DMH, mimicked the arousal-accelerating effects of AM281. In contrast, CB1R deletion from brain GABAergic neurons or hypothalamic glutamatergic neurons did not affect recovery time from anesthesia. Inactivation of PFC-DMH, DMH-VLPO, or DMH-Pef projections blocked AM281-accelerated arousal, whereas activation of these projections mimicked the effects of AM281. We propose that decreased eCB signaling at glutamatergic terminals of the PFC-DMH projection accelerates arousal from general anesthesia through enhancement of the excitatory DMH-Pef projection, the inhibitory DMH-VLPO projection, or both.

Electroacupuncture pretreatment inhibits NADPH oxidase-mediated oxidative stress in diabetic mice with cerebral ischemia.

We investigated the protective effect of electroacupuncture (EA) on cerebral ischemic injury in diabetic mice, and explored the role of NADPH oxidase-mediated oxidative stress. Male C57BL/6 mice were injected streptozotocin to induce diabetes. The mice were pretreated with EA at acupoint "Baihui" for 30 min. Two hours after the end of EA pretreatment, focal cerebral ischemia was induced following 24h reperfusion. The neurobehavioral scores and infarction volumes, malondialdehyde (MDA), reactive oxygen species (ROS), and activation of NADPH oxidase were determined in the presence or absence of the NADPH oxidase inhibitor apocynin or activator tetrabromocinnamic acid (TBCA). EA pretreatment reduced infarct size and improved neurological outcomes 24h after reperfusion in the diabetic mice. EA also decreased cerebral MDA and ROS levels compared with the control group, and inhibited the NADPH oxidase activation. The beneficial effects were abolished by TBCA while pretreatment with apocynin mimicked the neuroprotective and anti-oxidative effects of EA. Our results demonstrated that EA attenuated cerebral ischemic injury by inhibiting NAPDH oxidase-mediated oxidative damage in diabetic mice. These results suggest a novel mechanism of EA pretreatment-induced tolerance in diabetic cerebral ischemia.

Electroacupuncture attenuates reference memory impairment associated with astrocytic NDRG2 suppression in APP/PS1 transgenic mice.

Electroacupuncture (EA) has demonstrated therapeutic potential for the treatment of Alzheimer's disease (AD). A previous study reported that N-myc downstream-regulated gene 2 (NDRG2) was upregulated in the brain of patients with AD. In the present study, we investigated the effects of repeated EA administration on reference memory impairment and the role of NDRG2 in an amyloid precursor protein (APP)/presenilin-1 (PS1) double transgenic mouse model. Age-matched wild-type and transgenic mice were treated with EA (once per day for 30 min) for 4 weeks (four courses of 5 days EA administration and 2 days rest) beginning at 10 months of age. At seven and ten postnatal months of age and following a 4-week EA treatment regime, mice received training in the Morris water maze (MWM) and a probe test. Brain tissue was analyzed via Western blot and double-label immunofluorescence. Beginning at 7 months of age, APP/PS1 mice began to exhibit deficits in reference memory in the MWM test, an impairment associated with upregulation of glial fibrillary acidic protein (GFAP) and NDRG2. Four weeks of EA administration significantly ameliorated cognitive impairments and suppressed GFAP and NDRG2 upregulation. In conclusion, our findings demonstrated that EA administration can alleviate reference memory deficits and suppress NDRG2 upregulation in an AD transgenic mouse model. This study provides supportive evidence for EA as an effective therapeutic intervention for AD, as well as NDRG2 as a novel target for AD treatment.

NDRG2 is involved in anti-apoptosis induced by electroacupuncture pretreatment after focal cerebral ischemia in rats.

OBJECTIVE: We first reported that electroacupuncture (EA) pretreatment at the Baihui acupoint (GV20) induces ischemic tolerance. Our recent study demonstrated that N-Myc downstream-regulated gene 2 (NDRG2) expression was up-regulated following transient focal cerebral ischemia. Therefore, we investigated whether NDRG2 was involved in the ischemic tolerance induced by EA pretreatment in rats. METHODS: Twenty-four hours after the end of the last EA pretreatment, focal cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) for 120 minutes in male Sprague-Dawley rats. The neurobehavioral score, infarction volume, and extent of neuronal apoptosis were evaluated at 24 hours after reperfusion. The expression of NDRG2 in the brain was evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR), western blotting, and immunofluorescent staining. RESULTS: Electroacupuncture pretreatment decreased infarction volume and improved neurologic scores at 24 hours after reperfusion. Double immunofluorescence revealed that NDRG2 expression in astrocytes was suppressed in the EA group at 24 hours after reperfusion, and that NDRG2 protein expression was weak in the nucleus and strong in the cytoplasm of the EA group, but strong in the nucleus of the MCAO group. Triple immunofluorescent staining for terminal deoxynucleotidyl transferase nick-end labeling (TUNEL), NDRG2, and 4',6-diamidino-2-phenylindole (DAPI) showed that NDRG2 co-localised with apoptotic cells. Moreover, the number of apoptotic cells decreased with the attenuation of NDRG2 expression in the EA group compared to the MCAO group. CONCLUSION: Our results indicated that NDRG2 is involved in anti-apoptosis induced by EA pretreatment after focal cerebral ischemia in rats. N-Myc downstream-regulated gene 2 was involved in EA pretreatment-induced cerebral ischemic tolerance. These findings may be important for our understanding of the cellular signaling pathways induced by EA pretreatment.

Cardioprotective effect of transcutaneous electric acupoint stimulation in the pediatric cardiac patients: a randomized controlled clinical trial.

BACKGROUND: Acupuncture pretreatment exerts neuroprotective and cardioprotective effects in animal models and in adult patients underwent cardiac surgery; however, data in pediatric patient are unavailable. OBJECTIVE/AIM: To investigate the effects of transcutaneous electric acupoint stimulation (TEAS) on acute myocardial injury from pediatric open-heart surgery. METHODS: Children, aged 2-12 years, with congenital heart defects scheduled for surgical repair were enrolled. They were randomized to TEAS (administrated at bilateral P6 acupoint for 30 min after basal anesthesia) and control (an electrode was placed on the arm without stimulus) groups. The primary end point was serum cardiac troponin I (cTnI) over 24 h after aortic unclamping. Furthermore, clinical outcome and serum cytokine and C-reactive protein concentrations were evaluated. RESULTS: Seventy eligible children were analyzed, 36 in controls and 34 in TEAS group. Compared with controls, the mean cTnI levels were significantly lower in TEAS group at 8 h (P = 0.043) and 24 h (P = 0.046) after aortic unclamping. The duration of ventilation (P = 0.004) and length of ICU stay (P = 0.032) was significantly longer in controls than in TEAS group. There was a significant difference in the release of C-reactive protein at 8 h (P = 0.039) between two groups, whereas the values for cytokines were not significant. CONCLUSION: Transcutaneous electric acupoint stimulation on the bilateral P6 acupoint is effective for attenuation myocardial injury in children undergoing cardiac surgery. The beneficial effects may be partially associated with reduction in cTnI and C-reactive protein level in the early postoperative period.