Regulation of wakefulness by astrocytes in the lateral hypothalamus.

The lateral hypothalamus (LH) is an important brain region mediating sleep-wake behavior. Recent evidence has shown that astrocytes in central nervous system modulate the activity of adjacent neurons and participate in several physiological functions. However, the role of LH astrocytes in sleep-wake regulation remains unclear. Here, using synchronous recording of electroencephalogram/electromyogram in mice and calcium signals in LH astrocytes, we show that the activity of LH astrocytes is significantly increased during non-rapid eye movement (NREM) sleep-to-wake transitions and decreased during Wake-to-NREM sleep transitions. Chemogenetic activation of LH astrocytes potently promotes wakefulness and maintains long-term arousal, while chemogenetic inhibition of LH astrocytes decreases the total amount of wakefulness in mice. Moreover, by combining chemogenetics with fiber photometry, we show that activation of LH astrocytes significantly increases the calcium signals of adjacent neurons, especially among GABAergic neurons. Taken together, our results clearly illustrate that LH astrocytes are a key neural substrate regulating wakefulness and encode this behavior through surrounding GABAergic neurons. Our findings raise the possibility that overactivity of LH astrocytes may be an underlying mechanism of clinical sleep disorders.

Acupuncture inhibits mammalian target of rapamycin, promotes autophagy and attenuates neurological deficits in a rat model of hemorrhagic stroke.

BACKGROUND: Intracerebral hemorrhage (ICH) accounts for approximately 15% of all stroke cases. Previous studies suggested that acupuncture may improve ICH-induced neurological deficits. Therefore, we investigated the effects of acupuncture on neurological deficits in an animal model of ICH. METHODS: Adult male Sprague-Dawley rats were injected with autologous blood (50 µL) into the right caudate nucleus. Additional rats underwent sham surgery as controls. ICH rats either received acupuncture (GV20 through GB7 on the side of the lesion) or sham acupuncture (1 cm to the right side of the traditional acupuncture point locations). Some ICH rats received acupuncture plus rapamycin injection into the right lateral ventricle. Neurological deficits in the various groups were assessed based on composite neurological score. The perihemorrhagic penumbra was analyzed by histopathology following hematoxylin-eosin staining. Levels of autophagy-related proteins light chain (LC)3 and p62 as well as of mammalian target of rapamycin (mTOR)-related proteins, and phosphorylated (p)-mTOR and p-S6K1 (ribosomal protein S6 kinase beta-1), were assessed by Western blotting. RESULTS: Acupuncture significantly improved composite neurological scores 7 days after ICH (17.7 ± 1.49 vs 14.8 ± 1.32, p < 0.01). Acupuncture augmented autophagosome and autolysosome accumulation based on transmission electron microscopy. Acupuncture significantly increased expression of LC3 (p < 0.01) but decreased expression of p62 (p < 0.01). Acupuncture also reduced levels of p-mTOR and p-S6K1 (both p < 0.01). CONCLUSION: Acupuncture improved neurological deficits in a rat model of ICH, possibly by inhibiting the mTOR pathway and activating autophagy.

[Effect of acupuncture on NLRP3 inflammatory corpuscle in rats with intracerebral hemorrhage].

OBJECTIVE: To observe the effect of acupuncture at "Baihui" (GV 20) through "Qubin" (GB 7) on NLRP3 inflammatory corpuscle in rats with intracerebral hemorrhage (ICH), and to explore the action mechanism of acupuncture on promoting the recovery of neural function in rats with ICH. METHODS: Forty SPF six-week-old male SD rats were randomly divided into a sham operation group, a model group, a non-acupoint group and an acupuncture group, 10 rats in each group. The rats in the model group, non-acupoint group and acupuncture group were intervened with autologous blood injection to prepare ICH model, while the rats in the sham operation group were only intervened with operation but not injection with autologous blood. About 3 hours after the establishment of the model, the rats in the acupuncture group were intervened with acupuncture at "Baihui" (GV 20) through "Qubin" (GB 7), once every 12 hours, for 7 days; the rats in the non-acupoint group were intervened with acupuncture at the non-acupoint [parallel to the "Baihui" (GV 20), 1 cm next to the midline] on the affected side, and other treatment was the same as the acupuncture group. At the end of the intervention, the composite nerve function score of each group was evaluated; the histomorphology of the hemorrhage penumbra was observed by HE staining; the expression of NLRP3 inflammatory corpuscle in the brain was detected by immunohistochemistry; the relative protein expression levels of NLRP3, interleukin-1ß (IL-1ß) and interleukin-18 (IL-18) in brain were detected by the method of Western blot. RESULTS: Seven days into intervention, compared with the sham operation group, each item score and total score of composite nerve function in the model group were significantly reduced (P<0.01, P<0.05). There was edema and karyopyknosis in brain neuron as well as necrocytosis and inflammatory cell infiltration in the model group. Compared with the model group and the non-acupoint group, the total score of composite nerve function and the scores of symmetrical movement of limbs (LS) and proprioception of tentacles (VP) in the acupuncture group were increased (P<0.01, P<0.05), and the cell necrosis and inflammatory cell infiltration were relieved. Compared with the sham operation group, NLRP3 inflammatory corpuscle expression and the relative protein expression levels of NLRP3, IL-1ß and IL-18 in brain tissue in the model group were increased (P<0.01); compared with the model group and the non-acupoint group, NLRP3 inflammatory corpuscle expression and the relative protein expression levels of NLRP3, IL-1ß and IL-18 in brain tissue in the acupuncture group were reduced (P<0.01). CONCLUSION: Acupuncture at "Baihui" (GV 20) through "Qubin" (GB 7) could downregulate the expression of NLRP3, IL-1ß and IL-18 in the brain tissue of ICH rats, inhibit the inflammatory response, and promote the recovery of neural function.