Astrocytes are the largest glial population in the mammalian brain. However, we have a minimal understanding of astrocyte development, especially fate specification in different regions of the brain. Through lineage tracing of the progenitors of the third ventricle (3V) wall via in-utero electroporation in the embryonic mouse brain, we show the fate specification and migration pattern of astrocytes derived from radial glia along the 3V wall. Unexpectedly, radial glia located in different regions along the 3V wall of the diencephalon produce distinct cell types: radial glia in the upper region produce astrocytes and those in the lower region produce neurons in the diencephalon. With genetic fate mapping analysis, we reveal that the first population of astrocytes appears along the zona incerta in the diencephalon. Astrogenesis occurs at an early time point in the dorsal region relative to that in the ventral region of the developing diencephalon. With transcriptomic analysis of the region-specific 3V wall and lateral ventricle (LV) wall, we identified cohorts of differentially-expressed genes in the dorsal 3V wall compared to the ventral 3V wall and LV wall that may regulate astrogenesis in the dorsal diencephalon. Together, these results demonstrate that the generation of astrocytes shows a spatiotemporal pattern in the developing mouse diencephalon.
Mice ; Animals ; Astrocytes ; Neuroglia/physiology* ; Diencephalon ; Brain ; Neurons ; Mammals

It is well established that increased excitability of the presympathetic neurons in the hypothalamic paraventricular nucleus (PVN) during hypertension leads to heightened sympathetic outflow and hypertension. However, the mechanism underlying the overactivation of PVN presympathetic neurons remains unclear. This study aimed to investigate the role of endogenous corticotropin-releasing factor (CRF) on the excitability of presympathetic neurons in PVN using Western blot, arterial blood pressure (ABP) and renal sympathetic nerve activity (RSNA) recording, CRISPR/Cas9 technique and patch-clamp technique. The results showed that CRF protein expression in PVN was significantly upregulated in spontaneously hypertensive rats (SHRs) compared with normotensive Wistar-Kyoto (WKY) rats. Besides, PVN administration of exogenous CRF significantly increased RSNA, heart rate and ABP in WKY rats. In contrast, knockdown of upregulated CRF in PVN of SHRs inhibited CRF expression, led to membrane potential hyperpolarization, and decreased the frequency of current-evoked firings of PVN presympathetic neurons, which were reversed by incubation of exogenous CRF. Perfusion of rat brain slices with artificial cerebrospinal fluid containing CRF receptor 1 (CRFR1) blocker, NBI-35965, or CRF receptor 2 (CRFR2) blocker, Antisauvagine-30, showed that blocking CRFR1, but not CRFR2, hyperpolarized the membrane potential and inhibited the current-evoked firing of PVN presympathetic neurons in SHRs. However, blocking CRFR1 or CRFR2 did not affect the membrane potential and current-evoked firing of presympathetic neurons in WKY rats. Overall, these findings indicate that increased endogenous CRF release from PVN CRF neurons enhances the excitability of presympathetic neurons via activation of CRFR1 in SHRs.
Rats ; Animals ; Rats, Inbred SHR ; Paraventricular Hypothalamic Nucleus/physiology* ; Receptors, Corticotropin-Releasing Hormone/metabolism* ; Rats, Inbred WKY ; Corticotropin-Releasing Hormone/metabolism* ; Neurons/physiology* ; Hypertension ; Sympathetic Nervous System

The nucleus tractus solitarii (NTS) is one of the morphologically and functionally defined centers that engage in the autonomic regulation of cardiovascular activity. Phenotypically-characterized NTS neurons have been implicated in the differential regulation of blood pressure (BP). Here, we investigated whether phenylethanolamine N-methyltransferase (PNMT)-expressing NTS (NTS^PNMT) neurons contribute to the control of BP. We demonstrate that photostimulation of NTS^PNMT neurons has variable effects on BP. A depressor response was produced during optogenetic stimulation of NTS^PNMT neurons projecting to the paraventricular nucleus of the hypothalamus, lateral parabrachial nucleus, and caudal ventrolateral medulla. Conversely, photostimulation of NTS^PNMT neurons projecting to the rostral ventrolateral medulla produced a robust pressor response and bradycardia. In addition, genetic ablation of both NTS^PNMT neurons and those projecting to the rostral ventrolateral medulla impaired the arterial baroreflex. Overall, we revealed the neuronal phenotype- and circuit-specific mechanisms underlying the contribution of NTS^PNMT neurons to the regulation of BP.
Solitary Nucleus/metabolism* ; Blood Pressure/physiology* ; Phenylethanolamine N-Methyltransferase/metabolism* ; Neurons/metabolism* ; Paraventricular Hypothalamic Nucleus/metabolism*

The incidence rate of anxiety and depression is significantly higher in patients with inflammatory bowel diseases (IBD) than in the general population. The mechanisms underlying dextran sulfate sodium (DSS)-induced depressive-like behaviors are still unclear. We clarified that IBD mice induced by repeated administration of DSS presented depressive-like behaviors. The paraventricular thalamic nucleus (PVT) was regarded as the activated brain region by the number of c-fos-labeled neurons. RNA-sequencing analysis showed that lipocalin 2 (Lcn2) was upregulated in the PVT of mice with DSS-induced depressive behaviors. Upregulating Lcn2 from neuronal activity induced dendritic spine loss and the secreted protein induced chemokine expression and subsequently contributed to microglial activation leading to blood-brain barrier permeability. Moreover, Lcn2 silencing in the PVT alleviated the DSS-induced depressive-like behaviors. The present study demonstrated that elevated Lcn2 in the PVT is a critical factor for DSS-induced depressive behaviors.
Mice ; Humans ; Animals ; Lipocalin-2/genetics* ; Midline Thalamic Nuclei ; Brain ; Inflammatory Bowel Diseases ; Proto-Oncogene Proteins c-fos ; Mice, Inbred C57BL

Humans ; Alzheimer Disease ; Hippocampus ; Neurons ; Hypothalamus

A growing number of studies have identified sex differences in response to general anesthesia; however, the underlying neural mechanisms are unclear. The medial preoptic area (MPA), an important sexually dimorphic structure and a critical hub for regulating consciousness transition, is enriched with estrogen receptor alpha (ERα), particularly in neuronal clusters that participate in regulating sleep. We found that male mice were more sensitive to sevoflurane. Pharmacological inhibition of ERα in the MPA abolished the sex differences in sevoflurane anesthesia, in particular by extending the induction time and facilitating emergence in males but not in females. Suppression of ERα in vitro inhibited GABAergic and glutamatergic neurons of the MPA in males but not in females. Furthermore, ERα knockdown in GABAergic neurons of the male MPA was sufficient to eliminate sex differences during sevoflurane anesthesia. Collectively, MPA ERα positively regulates the activity of MPA GABAergic neurons in males but not in females, which contributes to the sex difference of mice in sevoflurane anesthesia.
Anesthesia ; Animals ; Estrogen Receptor alpha/metabolism* ; Female ; Male ; Mice ; Preoptic Area ; Sevoflurane/pharmacology* ; Sex Characteristics

Obesity and aging are two important epidemic factors for metabolic syndrome and many other health issues, which contribute to devastating diseases such as cardiovascular diseases, stroke and cancers. The brain plays a central role in controlling metabolic physiology in that it integrates information from other metabolic organs, sends regulatory projections and orchestrates the whole-body function. Emerging studies suggest that brain dysfunction in sensing various internal cues or processing external cues may have profound effects on metabolic and other physiological functions. This review highlights brain dysfunction linked to genetic mutations, sex, brain inflammation, microbiota, stress as causes for whole-body pathophysiology, arguing brain dysfunction as a root cause for the epidemic of aging and obesity-related disorders. We also speculate key issues that need to be addressed on how to reveal relevant brain dysfunction that underlines the development of these disorders and diseases in order to develop new treatment strategies against these health problems.
Aging ; Brain/metabolism* ; Energy Metabolism ; Humans ; Hypothalamus/metabolism* ; Obesity/metabolism*

OBJECTIVE: Depression and metabolic disorders have overlapping psychosocial and pathophysiological causes. Current research is focused on the possible role of adiponectin in regulating common biological mechanisms. Xiaoyao San (XYS), a classic Chinese medicine compound, has been widely used in the treatment of depression and can alleviate metabolic disorders such as lipid or glucose metabolism disorders. However, the ability of XYS to ameliorate depression-like behavior as well as metabolic dysfunction in mice and the underlying mechanisms are unclear. METHODS: An in vivo animal model of depression was established by chronic social defeat stress (CSDS). XYS and fluoxetine were administered by gavage to the drug intervention group. Depression-like behaviors were analyzed by the social interaction test, open field test, forced swim test, and elevated plus maze test. Glucose levels were measured using the oral glucose tolerance test. The involvement of certain molecules was validated by immunofluorescence, histopathology, and Western blotting. In vitro, hypothalamic primary neurons were exposed to high glucose to induce neuronal damage, and the neuroprotective effect of XYS was evaluated by cell counting kit-8 assay. Immunofluorescence and Western blotting were used to evaluate the influences of XYS on adiponectin receptor 1 (AdipoR1), adenosine 5'-monophosphate-activated protein kinase (AMPK), acetyl-coenzyme A carboxylase (ACC) and other related proteins. RESULTS: XYS ameliorated CSDS-induced depression-like behaviors and glucose tolerance impairment in mice and increased the level of serum adiponectin. XYS also restored Nissl bodies in hypothalamic neurons in mice that exhibited depression-like behaviors and decreased the degree of neuronal morphological damage. In vivo and in vitro studies indicated that XYS increased the expression of AdipoR1 in hypothalamic neurons. CONCLUSION Adiponectin may be a key regulator linking depression and metabolic disorders; regulation of the hypothalamic AdipoR1/AMPK/ACC pathway plays an important role in treatment of depression by XYS.
AMP-Activated Protein Kinases/metabolism* ; Acetyl-CoA Carboxylase/metabolism* ; Adiponectin/metabolism* ; Animals ; Antidepressive Agents/pharmacology* ; China ; Depression/drug therapy* ; Disease Models, Animal ; Drugs, Chinese Herbal/therapeutic use* ; Glucose ; Hypothalamus/metabolism* ; Mice ; Receptors, Adiponectin/metabolism*

Olfaction and food intake are interrelated and regulated. In the process of feeding, the metabolic signals in the body and the feeding signals produced by food stimulation are first sensed by the arcuate nucleus of hypothalamus and the nucleus tractus solitarius of brain stem, and then these neurons project to the paraventricular nucleus of hypothalamus. The paraventricular nucleus transmits the signals to other brain regions related to feeding and regulates feeding behavior. In this process, olfactory signals can be transmitted to hypothalamus through olfactory bulb and olfactory cortex to regulate feeding behavior. At the same time, gastrointestinal hormones (ghrelin, insulin, leptin, etc.) and some neurotransmitters (acetylcholine, norepinephrine, serotonin, endocannabinoid, etc.) produced in the process of feeding act on the olfactory system to regulate olfactory function, which in turn affects the feeding itself. This review summaries the research progress of the interaction between olfaction and food intake and its internal mechanism from the aspects of neuronal and hormonal regulation.
Arcuate Nucleus of Hypothalamus/metabolism* ; Feeding Behavior/physiology* ; Hypothalamus ; Paraventricular Hypothalamic Nucleus ; Smell

OBJECTIVE: To observe the effect of electroacupuncture (EA) on protein expressions of suppressor of cytokine signaling 3 (SOCS3) and insulin receptor substrate-1 (IRS-1) in hypothalamus and morphology of pancreas islet in Zucker diabetic fatty (ZDF) rats, and to explore its possible mechanism on improving plasma glucose and insulin resistance of type 2 diabetes mellitus (T2DM). METHODS: Twelve SPF male ZDF rats were selected and fed with high-fat diet for 4 weeks to establish the T2DM model, after modeling, the rats were randomly divided into a model group and an EA group, 6 rats in each one. Besides, 6 SPF male Zucker lean rats were selected as a blank group. In the EA group, EA was applied at "Pishu" (BL 20), "Weiwanxiashu" (EX-B 3), "Zusanli" (ST 36) and "Sanyinjiao" (SP 6), with continuous wave, 15 Hz in frequency, 2 mA in intensity, once a day, 20 min each time, 6 times a week for 4 weeks. The fasting plasma glucose (FPG) was measured before and after intervention. The serum level of fasting insulin (FINS) was measured by radioimmunoassay, and the homeostasis model assessment of insulin resistance index (HOMA-IR) was calculated; the morphological change of pancreas islets was observed by HE staining; the protein expressions of SOCS3 and IRS-1 in hypothalamus were detected by Western blot. RESULTS: Before intervention, compared with the blank group, FPG in the model group and the EA group was increased (P<0.01). After intervention, compared with the blank group, FPG, serum level of FINS and HOMA-IR were increased (P<0.01), the protein expression of SOCS3 was increased while IRS-1 was decreased in the hypothalamus in the model group (P<0.01). Compared with the model group, FPG, serum level of FINS and HOMA-IR were decreased (P<0.01), the protein expression of SOCS3 was decreased while IRS-1 was increased in the hypothalamus in the EA group (P<0.01). In the model group, the shape of pancreas islets was irregular, the area of pancreas islets and the number of islet β cell nuclei were decreased, the nuclei of islet β cell was compensatory enlargement. In the EA group, the shape and the area of pancreas islets and the number of islet β cell nuclei were improved, the compensatory increase of islet β cell nuclei was alleviated compared with the model group. CONCLUSION Electroacupuncture can reduce the fasting plasma glucose, improve the morphology of pancreas islets, and alleviate the insulin resistance in ZDF rats. The mechanism may relate to the down-regulation of SOCS3 and up-regulation of IRS-1 in the hypothalamus, and improving the function of hypothalamus in regulating peripheral glucose metabolism.
Acupuncture Points ; Animals ; Blood Glucose/metabolism* ; Diabetes Mellitus, Type 2/therapy* ; Electroacupuncture ; Hypothalamus/metabolism* ; Insulin Receptor Substrate Proteins/metabolism* ; Insulin Resistance ; Male ; Pancreas/metabolism* ; Rats ; Rats, Zucker ; Suppressor of Cytokine Signaling 3 Protein/metabolism*