OBJECTIVE: To observe the effect of electroacupuncture (EA) preconditioning at heart meridian acupoints on the contents of dopamine (DA) and 5-hydroxytryptamine (5-HT) in lateral hypothalamus area (LHA) and cerebellar fastigial nucleus (FN) in the rats with acute myocardial ischemia-reperfusion injury (MIRI), and explore the role and mechanism of LHA and FN in the effect of EA at heart meridian acupoints against acute MIRI. METHODS: Sixty SD rats were randomly divided into a sham-operation group, a model group, an EA heart meridian group and an EA lung meridian group, 12 rats in each group, as well as an LHA plus heart meridian group (damage of bilateral LHA) and an FN plus heart meridian group (damage of bilateral FN), 6 rats in each one. Three days after nucleus destruction, EA was applied to "Shenmen" (HT 7) and "Tongli" (HT 5) in the EA heart meridian group, the LHA plus heart meridian group and the FN plus heart meridian group and EA was applied to "Taiyuan" (LU 9) and "Lieque" (LU 7) in the EA lung meridian group, with 1 V in stimulating voltage and 2 Hz in frequency, lasting 20 minutes each time, once a day, for consecutively 7 days before model replication. Except in the sham-operation group, MIRI rat models were duplicated by ligation of the left anterior descending branch of the coronary artery in the rest groups. Using Power lab physiological recorder, ST segment displacement value was recorded before modeling, 30 min after ligation and 120 min after reperfusion separately. The high performance liquid chromatography-electrochemical detection and analysis system was adopted to determine the contents of DA and 5-HT in LHA and FN dialysate after rat modeling in each group. RESULTS: In comparison of ST segment displacement value 30 min after ligation and 120 min after reperfusion among groups, the value in the model group was higher than that in the sham-operation group ( CONCLUSION EA preconditioning at heart meridian acupoints can effectively alleviate myocardial injury in acute MIRI rats, during which, DA and 5-HT in LHA and FN may be the important material basis.
Acupuncture Points ; Animals ; Cerebellar Nuclei ; Dopamine ; Electroacupuncture ; Hypothalamic Area, Lateral ; Myocardial Ischemia ; Myocardial Reperfusion Injury/therapy* ; Rats ; Rats, Sprague-Dawley ; Serotonin

Chronic stress induces anxiety disorders, whereas physical exercise is believed to help people with clinical anxiety. In the present study, we investigated the mechanisms underlying stress-induced anxiety and its counteraction by exercise using an established animal model of anxiety. Mice treated with restraint for 2 h daily for 14 days exhibited anxiety-like behaviors, including social and nonsocial behavioral symptoms, and these behavioral impairments lasted for more than 12 weeks after the stress treatment was removed. Despite these lasting behavioral changes, wheel-running exercise treatment for 1 h daily from post-stress days 1 - 21 counteracted anxiety-like behaviors, and these anxiolytic effects of exercise persisted for more than 2 months, suggesting that anxiolytic effects of exercise stably induced. Repeated restraint treatment up-regulated the expression of the neuropeptide, melanin-concentrating hormone (MCH), in the lateral hypothalamus, hippocampus, and basolateral amygdala, the brain regions important for emotional behaviors. In an in vitro study, treatment of HT22 hippocampal cells with glucocorticoid increased MCH expression, suggesting that MCH upregulation can be initially triggered by the stress hormone, corticosterone. In contrast, post-stress treatment with wheel-running exercise reduced the stress-induced increase in MCH expression to control levels in the lateral hypothalamus, hippocampus and basolateral amygdala. Administration of an MCH receptor antagonist (SNAP94847) to stress-treated mice was therapeutic against stress-induced anxiety-like behaviors. These results suggest that repeated stress produces long-lasting anxiety-like behaviors and upregulates MCH in the brain, while exercise counteracts stress-induced MCH expression and persisting anxiety-like behaviors.
Animals ; Anti-Anxiety Agents ; Anxiety ; Anxiety Disorders ; Basolateral Nuclear Complex ; Behavioral Symptoms ; Brain* ; Corticosterone ; Exercise* ; Hippocampus ; Hypothalamic Area, Lateral ; In Vitro Techniques ; Mice ; Models, Animal ; Neuropeptides ; Up-Regulation*

Chronic stress induces changes in neuronal functions in specific brain regions regulating sociability and mood-related behaviors. Recently we reported that stress-induced persistent upregulation of the neuropeptides orexin and melanin-concentrating hormone (MCH) in the basolateral amygdala (BLA) and the resulting activation of orexin receptors or MCH receptors within the BLA produced deficits in sociability and mood-related behaviors. In the present study, we investigated the neural targets that were innervated by BLA neurons containing orexin receptors or MCH receptors. The viral vector system AAV2-CaMKII-ChR2-eYFP was injected into the BLA to trace the axonal tracts of BLA neurons. This axon labeling analysis led us to identify the prelimbic and infralimbic cortices, nucleus accumbens (NAc), dorsal striatum, paraventricular nucleus (PVN), interstitial nucleus of the posterior limb of the anterior commissure, habenula, CA3 pyramidal neurons, central amygdala, and ventral hippocampus as the neuroanatomical sites receiving synaptic inputs of BLA neurons. Focusing on these regions, we then carried out stimulus-dependent c-Fos induction analysis after activating orexin receptors or MCH receptors of BLA neurons. Stereotaxic injection of an orexin receptor agonist or an MCH receptor agonist in the BLA induced c-Fos expression in the NAc, PVN, central amygdala, ventral hippocampus, lateral habenula and lateral hypothalamus, which are all potentially important for depression-related behaviors. Among these neural correlates, the NAc, PVN and central amygdala were strongly activated by stimulation of orexin receptors or MCH receptors in the BLA, whereas other BLA targets were differentially and weakly activated. These results identify a functional connectivity of BLA neurons regulated by orexin and MCH receptor systems in sociability and mood-related behaviors.
Axons ; Basolateral Nuclear Complex* ; Brain ; Central Amygdaloid Nucleus ; Depression ; Extremities ; Habenula ; Hippocampus ; Hypothalamic Area, Lateral ; Neurons* ; Neuropeptides ; Nucleus Accumbens ; Orexin Receptors* ; Paraventricular Hypothalamic Nucleus ; Pyramidal Cells ; Up-Regulation

Dexmedetomidine (DEX), a highly selective alpha2-adrenergic receptor agonist, is the newest agent introduced for sedation in intensive care unit (ICU). The sedation strategy for critically ill patients has stressed light sedation with daily awakening and assessment for neurologic, cognitive, and respiratory functions, since Society of Critical Care Medicine (SCCM) guidelines were presented in 2002. The traditional GABAergic agents, including benzodiazepines and propofol, have some limitations for safe sedatives in this setting, due to an unfavorable pharmacokinetic profile and to detrimental adverse effects (such as lorazepam associated propylene glycol intoxication and propofol infusion syndrome). DEX produces it's sedative, analgesic and cardiovascular effects through alpha2 receptors on the locus ceruleus (LC). Activities of LC, the tuberomammillary nucleus (TMN) are depressed and activity of the ventrolateral preoptic nucleus (VLPO) is increased during DEX sedation, which is similar in features to normal non-REM (NREM) sleep. At the same time, perifornical orexinergic activity is maintained, which might be associated with attention. This mechanism of action produces a normal sleep-like, cooperative sedation. The characteristic feature of sedation, together with a concomitant opioid sparing effect, may decrease the length of time spent on a ventilator, length of stay in ICU, and prevalence and duration of delirium, as the evidence shown from several comparative studies. In addition, DEX has an excellent safety profile. In conclusion, DEX is considered as a promising agent optimized for sedation in ICU.
Alkenes ; Benzodiazepines ; Critical Care ; Critical Illness ; Delirium ; Dexmedetomidine ; GABA Agents ; Humans ; Hypnotics and Sedatives ; Hypothalamic Area, Lateral ; Intensive Care Units ; Length of Stay ; Light ; Locus Coeruleus ; Lorazepam ; Prevalence ; Propofol ; Propylene Glycol ; Ventilators, Mechanical

Histaminergic neurons solely originate from the tuberomammillary nucleus (TMN) in the posterior hypothalamus and send widespread projections to the whole brain. Experiments in rats show that histamine release in the central nervous system is positively correlated with wakefulness and the histamine released is 4 times higher during wake episodes than during sleep episodes. Endogeneous prostaglandin E2 and orexin activate histaminergic neurons in the TMN to release histamine and promote wakefulness. Conversely, prostaglandin D2 and adenosine inhibit histamine release by increasing GABA release in the TMN to induce sleep. This paper reviews the effects and mechanisms of action of the histaminergic system on sleep-wake regulation, and briefly discusses the possibility of developing novel sedative-hypnotics and wakefulness-promoting drugs related to the histaminergic system.
Adenosine ; physiology ; Animals ; Dinoprostone ; physiology ; Histamine ; metabolism ; physiology ; Hypothalamic Area, Lateral ; physiology ; Intracellular Signaling Peptides and Proteins ; physiology ; Neurons ; physiology ; Neuropeptides ; physiology ; Orexins ; Prostaglandin D2 ; physiology ; Sleep ; physiology ; Wakefulness ; physiology ; gamma-Aminobutyric Acid ; metabolism

In the present study, rat model of gastric ischemia-reperfusion (GI-R) injury was established by clamping the celiac artery for 30 min followed by 1 h of reperfusion. Subsequently, the regulatory effect of electrical stimulation of cerebellar fastigial nucleus (FN) on GI-R injury and its neural mechanisms were investigated in Sprague-Dawley rats. The results are as follows. Electrical stimulation of the cerebellar FN not only obviously attenuated the GI-R injury in an intensity-dependent manner, but also decreased the apoptosis rate of gastric mucosal cells. Chemical lesion of FN eliminated the protective effect of electrical stimulation of FN on GI-R injury. Electrical stimulation of cerebellar FN decreased both the frequency and amplitude of the discharges of greater splanchnic nerve, but it could not change the discharge of greater splanchnic nerve following the lesion of the lateral hypothalamic area (LHA). After bilateral section of the greater splanchnic nerves, electrical stimulation of the FN also attenuated the GI-R injury. Chemical lesion of the LHA reversed the protective effect of electrical stimulation of FN on GI-R injury. Electrical stimulation of FN increased the activity of superoxide dismutase (SOD), but decreased the content of malondialdehyde (MDA) in gastric mucosa under GI-R. These results indicate that the cerebellar FN may regulate GI-R injury. Therefore, the cerebellar FN is an important brain site protecting the stomach against GI-R. The LHA and greater splanchnic nerves participate in the regulatory effects of cerebellar FN stimulation on GI-R injury. In addition, antioxidation may also be involved in the protection mechanism of cerebellar FN stimulation.
Animals ; Apoptosis ; Cerebellar Nuclei ; physiology ; Electric Stimulation ; Gastric Mucosa ; cytology ; metabolism ; Hypothalamic Area, Lateral ; physiopathology ; Malondialdehyde ; metabolism ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; physiopathology ; Superoxide Dismutase ; metabolism

Signal transducer and activator of transcription 4 (STAT4), a STAT family member, mediates interleukin 12 (IL12) signal transduction. IL12 is known to be related to calorie-restricted status. In the central nervous system, IL12 also enhances the production of nitric oxide (NO), which regulates food intake. In this study, the expression of neuronal NO synthase (Nos1), which is also related to food intake, was investigated in the hypothalamic areas of Stat4 knockout (KO) mice using nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry, a marker for neurons expressing Nos1 enzyme. Western blots were also performed to evaluate Nos1 and Fos expression. Wild-type Balb/c (WT group, n=10 male) and Stat4 KO mice (Stat4 KO group, n=8 male) were used. The body weight and daily food intake in the WT group were 22.4+/-0.3 and 4.4 g per day, while those in the Stat4 KO group were 18.7+/-0.4 and 1.8 g per day, respectively. Stat4 mice had lower body weight and food intake than Balb/c mice. Optical intensities of NADPH-d-positive neurons in the paraventricular nucleus (PVN) and lateral hypothalamic area (LHA) of the Stat4 KO group were significantly higher than those of the WT group. Western blotting analysis revealed that the hypothalamic Nos1 and Fos expression of the Stat4 KO group was up-regulated, compared to that in the WT group. These results suggest that Stat4 may be related to the regulation of food intake and expression of Nos1 in the hypothalamus.
Animals ; Blotting, Western ; Body Weight ; Central Nervous System ; Eating ; Humans ; Hypothalamic Area, Lateral ; Hypothalamus ; Interleukin-12 ; Mice ; Mice, Knockout ; NAD ; Neurons ; Nitric Oxide ; Nitric Oxide Synthase ; Paraventricular Hypothalamic Nucleus ; Signal Transduction ; STAT4 Transcription Factor

A current hypothesis of sleep-wake regulation proposes that the sleep process starts with the activation of sleep-promoting neurons located in the preoptic area of the anterior hypothalamus. This activation leads to the inhibition of wake-promoting neurons located in the posterior hypothalamus, basal forebrain, and mesopontine tegmentum, which, in turn removes inhibition from the sleep-promoting structures(i.e., disinhibition) to initiate the sleep process. Mutual inhibition between these wake- and sleep-promoting neurons results in switching properties that define discrete wakeful and sleep states with sharp transitions between them. Wake-promoting nuclei include the orexinergic lateral hypothalamic/perifornical area, the histaminergic tuberomammillary nucleus, the cholinergic pedunculopontine tegmental nucleus, the noradrenergic locus coeruleus, the 5-hydroxytryptaminergic raphe nuclei, and possibly the dopaminergic ventral tegmental area. The major sleep-promoting nucleus is the GABAergic ventrolateral preoptic nucleus of the hypothalamus. The regulation of sleep is classically viewed as the dual interaction of circadian(SCN-based) and homeostatic processes, and the propensity to be asleep or awake at any given time is a consequence of a sleep debt and its interaction with signals from the SCN circadian clock. To better understand the mechanisms of sleep and wakefulness, the focus of pharmacotherapy is on targeting specific therapies to the particular defect in sleep-wake regulation.
Circadian Clocks ; Circadian Rhythm ; Drug Therapy* ; Hypothalamic Area, Lateral ; Hypothalamus ; Hypothalamus, Anterior ; Hypothalamus, Posterior ; Locus Coeruleus ; Neuroanatomy* ; Neurons ; Pedunculopontine Tegmental Nucleus ; Preoptic Area ; Prosencephalon ; Raphe Nuclei ; Sleep Wake Disorders ; Ventral Tegmental Area ; Wakefulness

OBJECTIVETo confirm the effect of Er'bao granule (EBG) on the sensitivity to peripheral afferent signal of neurons in lateral hypothalamic area (LHA) to illustrate the central mechanism of EBG in promoting ingestion behavior.

METHODSThe anorexia rat model was established by feeding special prepared forage for one week, and all the model rats were administrated with EBG by gavage for 3 weeks. The spontaneous discharge of LHA neurons was recorded using electro-physiological extracellular recording method, and its response to electrical stimulus on gastric vagus nerve and intravenous injection of glucose were observed and compared among the normal, model and treated groups.

RESULTSAs compared with the normal group, among the LHA neurons responding to afferent gastric vagal impulse, the proportion of glycemia-sensitive neurons in the model group was significantly decreased (P <0.01), but insignificant difference was shown in comparison between the treated group and the normal group.

CONCLUSIONEBG play a role in regulating the sensitivity of LHA neurons to peripheral afferent signal and thus to influence the multi-afferent information integration of ingestion central neurons.

Afferent Pathways ; drug effects ; Animals ; Anorexia ; drug therapy ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Electrophysiology ; Feeding Behavior ; drug effects ; Hypothalamic Area, Lateral ; physiopathology ; Neurons ; physiology ; Phytotherapy ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Vagus Nerve ; physiopathology

This study was aimed to investigate the changes of orexin-A (OXA) and neuropeptide Y (NPY) expression in the hypothalamus of the fasted and high-fat diet fed rats. For the experiments, the male Sprague-Dawley (SD) rats were used as the model of high-fat diet-induced obesity. The mean loss of body weight (MLBW) did not show the linear pattern during the fasting; from 24 h to 84 h of fastings, the MLBW was not significantly changed. The numbers of OXA-immunoreactive (IR) neurons were decreased at 84 h of fasting compared with those in other five fasting subgroups. The NPY immunoreactivities in the arcuate nucleus (ARC) and the suprachiasmatic nucleus (SCN) observed at 84 h of fasting were higher than that observed at 24 h of fasting. The number of OXA-IR neurons of the LHA (lateral hypothalamic area) in the high-fat (HF) diet fed group was more increased than that of the same area in the normal-fat (NF) diet fed group. The NPY immunoreactivities of the ARC and the SCN were higher in HF group than those observed in the same areas of NF group. Based on these results, it is noteworthy that the decrease of the body weight during the fast was not proportionate to the time-course, implicating a possible adaptation of the body for survival against starvation. The HF diet might activate the OXA and the NPY in the LHA to enhance food intake.
Adaptation, Physiological/physiology ; Animals ; Arcuate Nucleus/metabolism ; Dietary Fats ; Eating ; Fasting/*physiology ; Hypothalamic Area, Lateral/metabolism ; Hypothalamus/*metabolism ; Immunohistochemistry/veterinary ; Intracellular Signaling Peptides and Proteins/*metabolism ; Male ; Neuropeptide Y/*metabolism ; Neuropeptides/*metabolism ; Obesity ; Rats ; Rats, Sprague-Dawley/physiology ; Suprachiasmatic Nucleus/metabolism