Adverse experiences in early life have long-lasting negative impacts on behavior and the brain in adulthood, one of which is sleep disturbance. As the corticotropin-releasing hormone (CRH)-corticotropin-releasing hormone receptor 1 (CRHR1) system and nucleus accumbens (NAc) play important roles in both stress responses and sleep-wake regulation, in this study we investigated whether the NAc CRH-CRHR1 system mediates early-life stress-induced abnormalities in sleep-wake behavior in adult mice. Using the limited nesting and bedding material paradigm from postnatal days 2 to 9, we found that early-life stress disrupted sleep-wake behaviors during adulthood, including increased wakefulness and decreased non-rapid eye movement (NREM) sleep time during the dark period and increased rapid eye movement (REM) sleep time during the light period. The stress-induced sleep disturbances were accompanied by dendritic atrophy in the NAc and both were largely reversed by daily systemic administration of the CRHR1 antagonist antalarmin during stress exposure. Importantly, Crh overexpression in the NAc reproduced the effects of early-life stress on sleep-wake behavior and NAc morphology, whereas NAc Crhr1 knockdown reversed these effects (including increased wakefulness and reduced NREM sleep in the dark period and NAc dendritic atrophy). Together, our findings demonstrate the negative influence of early-life stress on sleep architecture and the structural plasticity of the NAc, and highlight the critical role of the NAc CRH-CRHR1 system in modulating these negative outcomes evoked by early-life stress.
Animals ; Mice ; Corticotropin-Releasing Hormone/metabolism* ; Nucleus Accumbens/metabolism* ; Receptors, Corticotropin-Releasing Hormone/metabolism* ; Sleep ; Sleep Wake Disorders ; Stress, Psychological/complications*

Animals ; Mice ; Corticotropin-Releasing Hormone/metabolism* ; Neurons/metabolism* ; Brain/metabolism*

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

Drugs of abuse leads to adaptive changes in the brain stress system, and produces negative affective states including aversion and anxiety after drug use is terminated. Corticotrophin-releasing hormone (CRH) is the main transmitter in control of response to stressors and is neuronal enriched in the central amygdala (CeA), a sub-region of the extended amygdala playing an important role in integrating emotional information and modulating stress response. The effect of CRH neurons in CeA on the negative emotions on morphine naïve and withdrawal mice is unclear. Thus, we utilized CRH-Cre transgenic mice injected with AAV-mediated Designer Receptors Exclusively Activated By Designer Drugs (DREADDs) to chemogenetically manipulate CRH neurons in CeA. And methods of behavior analysis, including conditioned place aversion (CPA), elevated plus maze and locomotor activity tests, were used to investigate morphine withdrawal-induced negative emotions in mice. The results showed that, inhibiting CRH neurons of CeA decreased the formation of morphine withdrawal-induced CPA, as well as the anxiety level of CRH-Cre mice. Furthermore, specifically activating CRH neurons in CeA evoked CPA and anxiety of morphine naïve mice. Neither inhibiting nor activating CRH neurons had effects on their locomotor activity. These results suggest that CRH neurons in CeA are involved in the mediation of morphine withdrawal-induced negative emotion in mice, providing a theoretical basis for drug addiction and relapse mechanism.
Adrenocorticotropic Hormone ; Animals ; Central Amygdaloid Nucleus ; Corticotropin-Releasing Hormone ; metabolism ; Emotions ; physiology ; Mice ; Morphine ; metabolism ; Neurons ; metabolism

BACKGROUND/AIMS: Gastrointestinal (GI) symptoms may develop when we fail to adapt to various stressors of our daily life. Central oxytocin (OXT) can counteract the biological actions of corticotropin-releasing factor (CRF), and in turn attenuates stress responses. Administration (intracerebroventricular) of OXT significantly antagonized the inhibitory effects of chronic complicated stress (CCS) on GI dysmotility in rats. However, intracerebroventricular administration is an invasive pathway. Intranasal administration can rapidly deliver peptides to the brain avoiding stress response. The effects of intranasal OXT on hypothalamus-pituitary-adrenal axis and GI motility in CCS conditions have not been investigated. METHODS: A CCS rat model was set up, OXT 5, 10, or 20 μg were intranasal administered, 30 minutes prior to stress loading. Central CRF and OXT expression levels were analyzed, serum corticosterone and OXT concentrations were measured, and gastric and colonic motor functions were evaluated by gastric emptying, fecal pellet output, and motility recording system. RESULTS: Rats in CCS condition showed significantly increased CRF expression and corticosterone concentration, which resulted in delayed gastric emptying and increased fecal pellet output, attenuated gastric motility and enhanced colonic motility were also recorded. OXT 10 μg or 20 μg significantly reduced CRF mRNA expression and the corticosterone concentration, OXT 20 μg also helped to restore GI motor dysfunction induced by CCS. CONCLUSION: Intranasal administration of OXT has an anxiolytic effect and attenuates the hypothalamus-pituitary-adrenal axis in response to CCS, and gave effects which helped to restore GI dysmotility, and might be a new approach for the treatment of stress-induced GI motility disorders.
Administration, Intranasal ; Animals ; Anti-Anxiety Agents ; Brain ; Colon ; Corticosterone ; Corticotropin-Releasing Hormone ; Gastric Emptying ; Gastrointestinal Motility ; Models, Animal ; Oxytocin ; Peptides ; Rats ; RNA, Messenger

Over the last 5 years, the Korean Ministry of Food and Drug Safety has approved four anti-obesity drugs for long-term weight management. In this review, the mechanisms of action and clinical applications of lorcaserin, naltrexone/bupropion, liraglutide, and phentermine/topiramate have been clarified. Lorcaserin stimulates proopiomelanocortin/cocaine- and amphetamine-regulated transcript neurons in the arcuate nucleus. Naltrexone/bupropion reduces body weight by controlling the hedonic reward system of food intake. The hypophagic effect of liraglutide depends on the direct activation of the proopiomelanocortin/cocaine- and amphetamine-regulated transcript neurons and indirect suppression of neuropeptide Y/agouti-related peptide neurons through gammaaminobutyric acid-dependent signaling, with an additional thermogenic effect. Phentermine/topiramate induces weight loss by elevating the norepinephrine levels in the hypothalamus, reducing energy deposition in the adipose tissue and skeletal muscle, and elevating the corticotropin-releasing hormone in the hypothalamus. In patients with high cardiovascular risks or type 2 diabetes mellitus, lorcaserin and liraglutide are appropriate. In patients with mood disorders, naltrexone/bupropion could be considered as the first choice of therapy. Notably, lorcaserin and liraglutide are neutral in the aspect of sleep disorder. In case of obese individuals with obstructive sleep apnea, liraglutide or phentermine/topiramate would be selected as the treatment option. These four drugs should be used after considering the patients' co-morbidities of obesity.
Adipose Tissue ; Anti-Obesity Agents ; Arcuate Nucleus of Hypothalamus ; Body Weight ; Corticotropin-Releasing Hormone ; Diabetes Mellitus, Type 2 ; Eating ; Humans ; Hypothalamus ; Korea ; Liraglutide ; Mood Disorders ; Muscle, Skeletal ; Neurons ; Neuropeptides ; Norepinephrine ; Obesity ; Pharmacology ; Reward ; Sleep Apnea, Obstructive ; Sleep Wake Disorders ; Weight Loss

BACKGROUND/AIMS: Functional dyspepsia (FD) and irritable bowel syndrome (IBS) are common gastrointestinal (GI) disorders and these patients frequently overlap. Trimebutine has been known to be effective in controlling FD co-existing diarrhea-dominant IBS, however its effect on overlap syndrome (OS) patients has not been reported. Therefore, we investigated the effect of trimebutine on the model of OS in guinea pigs. METHODS: Male guinea pigs were used to evaluate the effects of trimebutine in corticotropin-releasing factor (CRF) induced OS model. Different doses (3, 10, and 30 mg/kg) of trimebutine were administered orally and incubated for 1 hour. The next treatment of 10 μg/kg of CRF was intraperitoneally injected and stabilized for 30 minutes. Subsequently, intragastric 3 mL charcoal mix was administered, incubated for 10 minutes and the upper GI transit analyzed. Colonic transits were assessed after the same order and concentrations of trimebutine and CRF treatment by fecal pellet output assay. RESULTS: Different concentrations (1, 3, and 10 μg/kg) of rat/human CRF peptides was tested to establish the OS model in guinea pigs. CRF 10 μg/kg was the most effective dose in the experimental OS model of guinea pigs. Trimebutine (3, 10, and 30 mg/kg) treatment significantly reversed the upper and lower GI transit of CRF induced OS model. Trimebutine significantly increased upper GI transit while it reduced fecal pellet output in the CRF induced OS model. CONCLUSIONS: Trimebutine has been demonstrated to be effective on both upper and lower GI motor function in peripheral CRF induced OS model. Therefore, trimebutine might be an effective drug for the treatment of OS between FD and IBS patients.
Animals ; Charcoal ; Colon ; Corticotropin-Releasing Hormone ; Dyspepsia ; Guinea Pigs ; Guinea ; Humans ; Irritable Bowel Syndrome ; Male ; Peptides ; Trimebutine

OBJECTIVE: Corticotropin-releasing hormone (CRH) is a crucial regulator of human pregnancy and parturition. Adenosine triphosphate (ATP)-sensitive potassium (KATP) channels are important for regulating myometrial quiescence during pregnancy. We investigated regulatory effects of different concentrations of CRH on KATP channel expression in human myometrial smooth muscle cells (HSMCs) in in vitro conditions. METHODS: After treating HSMCs with different concentrations of CRH (1, 10, 102, 103, 104 pmol/L), mRNA and protein expression of KATP channel subunits (Kir6.1 and SUR2B) was analyzed by reverse transcription-polymerase chain reaction and western blot. We investigated which CRH receptor was involved in the reaction and measured the effects of CRH on intracellular Ca2+ concentration when oxytocin was administered in HSMCs using Fluo-8 AM ester. RESULTS: When HSMCs were treated with low (1 pmol/L) and high (103, 104 pmol/L) CRH concentrations, KATP channel expression significantly increased and decreased, respectively. SUR2B mRNA expression at low and high CRH concentrations was significantly antagonized by antalarmin (CRH receptor-1 antagonist) and astressin 2b (CRH receptor-2 antagonist), respectively; however, Kir6.1 mRNA expression was not affected. After oxytocin treatment, the intracellular Ca2+ concentration in CRH-treated HSMCs was significantly lowered in low concentration of CRH (1 pmol/L), but not in high concentration of CRH (103 pmol/L), compared to control. CONCLUSION: Our data demonstrated the regulatory effect was different when HSMCs were treated with low (early pregnancy-like) and high (labor-like) CRH concentrations and the KATP channel expression showed significant increase and decrease. This could cause inhibition and activation, respectively, of uterine muscle contraction, demonstrating opposite dual actions of CRH.
Adenosine Triphosphate ; Adenosine ; Animals ; Blotting, Western ; Corticotropin-Releasing Hormone ; Female ; Humans ; In Vitro Techniques ; KATP Channels ; Mice ; Myocytes, Smooth Muscle ; Myometrium ; Oxytocin ; Parturition ; Potassium Channels ; Potassium ; Pregnancy ; Receptors, Corticotropin-Releasing Hormone ; RNA, Messenger

Restraint water-immersion stress (RWIS), a compound stress model, has been widely used to induce acute gastric ulceration in rats. A wealth of evidence suggests that the central nucleus of the amygdala (CEA) is a focal region for mediating the biological response to stress. Different stressors induce distinct alterations of neuronal activity in the CEA; however, few studies have reported the characteristics of CEA neuronal activity induced by RWIS. Therefore, we explored this issue using immunohistochemistry and in vivo extracellular single-unit recording. Our results showed that RWIS and restraint stress (RS) differentially changed the c-Fos expression and firing properties of neurons in the medial CEA. In addition, RWIS, but not RS, induced the activation of corticotropin-releasing hormone neurons in the CEA. These findings suggested that specific neuronal activation in the CEA is involved in the formation of RWIS-induced gastric ulcers. This study also provides a possible theoretical explanation for the different gastric dysfunctions induced by different stressors.
Action Potentials ; drug effects ; physiology ; Analysis of Variance ; Animals ; Central Amygdaloid Nucleus ; pathology ; Corticotropin-Releasing Hormone ; metabolism ; Disease Models, Animal ; Gastric Mucosa ; pathology ; Gene Expression Regulation ; physiology ; Neurons ; physiology ; Patch-Clamp Techniques ; Proto-Oncogene Proteins c-fos ; metabolism ; Rats ; Rats, Wistar ; Stress, Physiological ; physiology ; Stress, Psychological ; etiology ; physiopathology

BACKGROUND/AIMS: When a person is experiencing stress, corticotropin-releasing hormone (CRH) can modulate gut physiologies, such as visceral sensation or gastrointestinal motility, and its intravenous administration mimics stress-induced physiological changes. However, the influence of CRH on the esophagus is yet unknown. Accordingly, we investigated whether intravenous CRH administration increases esophageal sensitivity to electrical stimulation in healthy Japanese subjects. METHODS: Twenty healthy subjects were recruited. We quantified the initial perception threshold (IPT) every 15 minutes after CRH injection. Venous blood was collected with a cannula, and both plasma adrenocorticotropic hormone (ACTH) and cortisol were measured at pre-stimulation, 0, 30, 60, 90, and 120 minutes. The results from each time point were compared against a baseline IPT obtained before electrical stimulation was initiated. RESULTS: When compared to the baseline IPT value (16.9 ± 4.5), CRH significantly decreased electrical threshold of the esophagus at 30, 45, 60, 75 minutes (14.1 ± 4.2, 13.1 ± 5.0, 12.1 ± 5.7, 14.0 ± 5.8 minutes, P < 0.01, respectively) after CRH injection, suggesting that CRH increased esophageal sensitivity to the electrical stimulus. CRH also significantly increased plasma ACTH levels at 30 minutes (50.3 ± 17.7, P < 0.01), and cortisol levels at 30 minutes (22.0 ± 6.7 minutes, P < 0.01) and 60 minutes (20.3 ± 6.7 minutes, P < 0.01) after CRH injection, when compared to the pre-stimulation ACTH and cortisol values. CONCLUSION: Intravenous CRH administration increased esophageal electrical sensitivity in normal subjects, emphasizing the important role of stress in esophageal sensitivity.
Administration, Intravenous ; Adrenocorticotropic Hormone ; Asian Continental Ancestry Group ; Catheters ; Corticotropin-Releasing Hormone* ; Electric Stimulation ; Esophagus ; Gastrointestinal Motility ; Healthy Volunteers ; Humans ; Hydrocortisone ; Plasma ; Sensation