Our research reveals the critical role of the suprachiasmatic nucleus (SCN) vasoactive intestinal peptide (VIP) neurons in mediating light-induced transient forgetting. Acute exposure to bright light selectively impairs trace fear memory by activating VIP neurons in the SCN, as demonstrated by increased c-Fos expression and Ca²⁺ recording. This effect can be replicated and reversed through optogenetic and chemogenetic manipulations of SCN VIP neurons. Furthermore, we identify the SCN → PVT (paraventricular nucleus of the thalamus) VIP neuronal circuitry as essential in this process. These findings establish a novel role for SCN VIP neurons in modulating memory accessibility in response to environmental light cues, extending their known function beyond circadian regulation and revealing a mechanism for transient forgetting.
Animals ; Vasoactive Intestinal Peptide/metabolism* ; Male ; Mice ; Neurons/metabolism* ; Suprachiasmatic Nucleus/physiology* ; Light ; Mice, Inbred C57BL ; Memory/physiology* ; Fear/physiology* ; Suprachiasmatic Nucleus Neurons/metabolism* ; Optogenetics ; Proto-Oncogene Proteins c-fos/metabolism*

The anterior cingulate cortex (ACC) has recently been proposed as a key player in the representation of itch stimuli. However, to date, little is known about the contribution of specific ACC interneuron populations to itch processing. Using c-Fos immunolabeling and in vivo Ca²⁺ imaging, we reported that both histamine and chloroquine stimuli-induced acute itch caused a marked enhancement of vasoactive intestinal peptide (VIP)-expressing interneuron activity in the ACC. Behavioral data indicated that optogenetic and chemogenetic activation of these neurons reduced scratching responses related to histaminergic and non-histaminergic acute itch. Similar neural activity and modulatory role of these neurons were seen in mice with chronic itch induced by contact dermatitis. Together, this study highlights the importance of ACC VIP⁺ neurons in modulating itch-related affect and behavior, which may help us to develop novel mechanism-based strategies to treat refractory chronic itch in the clinic.
Animals ; Pruritus/physiopathology* ; Vasoactive Intestinal Peptide/metabolism* ; Interneurons/metabolism* ; Gyrus Cinguli/metabolism* ; Mice ; Male ; Mice, Inbred C57BL ; Histamine ; Chloroquine ; Optogenetics ; Mice, Transgenic

OBJECTIVETo study the effects of sacral nerve root electrostimulation (SNS) on the colon function and its mechanisms in rats with spinal cord injury (SCI).

METHODSOne hundred and four Wistar rats were divided into three groups: A, B and C. A group ( n = 24) was divided into three subgroups (n = 8) for studying the bioelectricity: Normal group (NG), SCI group (SCI) and SCI group with SNS(SNS); B group( n = 24) was divided into three subgroups( n = 8) for studying the colon motility: NG, SCI and SNS. C group( n = 56) were divided into three groups for studying the change of morphology and neurotransmitters(SP and VIP): NG (n = 8), SCI (n = 24), and SNS (n = 24) . In SCI and SNS, included of three subgroups: 24, 48, 72 h after spinal cord injury (n = 8).

RESULTSIn SCI group, the activity of bioelectricity in proximal and distal colon was reduced; the colon motility was lessened, and colon mucosa appeared different degree of damage; cell-cell connections between intestinal epithelial cells were destroyed. The expressions of substance P(SP) and vasoactive intestinal peptide (VIP) in colon were decreased obviously. SNS was found to activate the bioelectricity, promote the colon motility, improve the intestinal mucosal, and increase the expressions of SP and VIP. Conclusion: SNS can activate the peristalsis, rehabilitate the motility of denervated colon, protection of the intestinal mechanical barrier between intestinal epithelial cells and tight junction, rebuild the colon function through activating the bioelectricity and increase the expressions of SP and VIP.

Animals ; Colon ; physiopathology ; Electric Stimulation Therapy ; Epithelial Cells ; drug effects ; Intestinal Mucosa ; drug effects ; Lumbosacral Region ; innervation ; Neurotransmitter Agents ; metabolism ; Rats ; Rats, Wistar ; Spinal Cord Injuries ; therapy ; Substance P ; metabolism ; Vasoactive Intestinal Peptide ; metabolism

OBJECTIVE: To explore the expression and significance of vasoactive intestinal peptide and Pituitary adenylate cyclase activiting polypeptide (VIP/PACAP) of nasal mucosa in rats with allergic rhinitis (AR), and the function of botulinum toxin-A(BTX-A) to inhibit the expression of VIP/PACAP in AR. METHOD: Thirty Sprague-Dawley rats were randomly divided into 3 groups, which were the AR group, the intervention group, and the control group. In the AR group, ovalbumin was used to sensitize healthy rats. In the intervention group, BTX-A was dripped into the nasal cavity of AR rats 7 times. In the control group, only physiological saline was used to drip into the nasal cavity of AR rats. Changes of the rats' behavior were observed. ELISA were used to detected the concentration variation of serum IFN-γ and IL-4. Histopathology and immunohistochemistry were employed to observe morphology in the rats' nasal mucosal and the expression of VIP/PACAP. Statistical analysis was also made. RESULT: (1)The typical symptoms marks of nasal scratching, sneezing, nasal blockage and rhinorrhea of AR group (7.5 ± 0.50) were higher than intervention group (1 ± 0.27) and control group (0.8 ± 0.31). (2) Comparing to intervention group and control group, the serm IFN-γ of the AR group obvious reduced (P < 0.05), the serm IL-4 of the AR group obvious rose (P < 0.01), and the serm Th1/Th2 (IFN-γ/IL-4) of the AR group obvious reduced (P < 0.01). (3) Comparing to intervention group and control group, the cilium loss, inflammatory cells infiltration, and inflammatory cells exudation of nasal mucosa in AR group were more obviously (P < 0.01), and the intervention group of the 3 indexes was obviously than control group. (4) The expression of VIP in the rats' nasal mucosa of the AR group (13.27 ± 2.74) were more intense than intervention group (5.21 ± 2.18) and control group (3.56 ± 5.30) (P < 0.01), and the expression of PACAP in the rats' nasal mucosa of the AR group (20.97 ± 2.14) were more intense than intervention group (6.33 ± 3.04) and control group (4.63 ± 1.25) (P < 0.01). (5) In all the 3 groups, there was positive correlation between expression of negative in VIP/PACAP and Thl/Th2 cell infiltration(r were respectively -0.340 and -0.223, P < 0.05). CONCLUSION The VIP/PACAP in the rats' nasal mucosa may play an important role in pathogenesis of AR, and BTX-A could improve the symptoms of AR through inhibition of the expression of VIP/ PACAP.
Animals ; Botulinum Toxins, Type A ; pharmacology ; Disease Models, Animal ; Interferon-gamma ; blood ; Interleukin-4 ; blood ; Nasal Mucosa ; drug effects ; metabolism ; Ovalbumin ; Paranasal Sinuses ; Pituitary Adenylate Cyclase-Activating Polypeptide ; antagonists & inhibitors ; metabolism ; Rats ; Rats, Sprague-Dawley ; Rhinitis, Allergic ; drug therapy ; Vasoactive Intestinal Peptide ; antagonists & inhibitors ; metabolism

To observe the effect of vasoactive intestinal peptide (VIP) on the metabolism of intestinal fluid and cyclic AMP protein kinase A signaling pathway (cAMP-PKA) and water channel protein 3 (AQP3) in rats with constipation, and to explore the mechanism of VIP in the treatment of constipation.
 Methods: A total of 45 healthy adult rats were randomly divided into a control group, a model group, a model +VIP group. After 4 weeks of VIP treatment, the first black stool time were examined with the ink gastric method; the water content in feces was calculated; the morphological changes in colonic tissues were observed by HE staining. The expression of VIP and AQP3 protein levels in colon tissues were detected by Western blot; and the cAMP, PKA, AQP3 mRNA expression levels were detected by quantitative real time polymerase chain reaction (qPCR). 
 Results: Compared with the control group, the first black stool time was prolonged, the water content of fecal decreased significantly (both P<0.01); part of the colon mucosa epithelial cells were destructed; the goblet cell volume decreased and quantity was reduced; the contents of AQP3 and VIP in colon tissues were significantly decreased, and the cAMP, PKA and AQP3 mRNA levels were decreased in the model group (all P<0.05). Compared with the model group, the first black stool time in the model +VIP group was shortened, the fecal water content increased significantly (both P<0.05); the mucosal epithelium integrity improved, the number of goblet cells increased; the content of AQP3 and VIP in colon tissues was increased, and the cAMP, PKA, and AQP3 mRNA levels were elevated (all P<0.05).
 Conclusion: Intravenous injection of VIP can regulate intestinal fluid metabolism and improve the symptoms of constipation in rats, which might be related to the regulation of VIP-cAMP-PKA-AQP3 signaling pathway.
Animals ; Aquaporin 3 ; physiology ; Aquaporins ; Blotting, Western ; Colon ; chemistry ; pathology ; Constipation ; physiopathology ; therapy ; Cyclic AMP ; physiology ; Defecation ; Epithelial Cells ; pathology ; Feces ; chemistry ; Goblet Cells ; pathology ; Intestinal Mucosa ; metabolism ; pathology ; RNA, Messenger ; Rats ; Signal Transduction ; Vasoactive Intestinal Peptide ; administration & dosage ; physiology ; therapeutic use

OBJECTIVETo observe effects of treatment from the lung and treatment from the intestine on the level of vasoactive intestinal peptide (VIP) in the lung and intestine of ulcerative colitis (UC) rats.

METHODSThe UC rat model was established in 52 rats by using rabbit intestine mucosa tissue allergen combined TNBS-ethanol model (with the model successful rate of 78.0%). Eight rats randomly selected from 40 successfully modeled rats and 8 of 16 rats from the normal group were recruited as the model group and the normal control group before intervention (at week 0). The rest 32 successfully modeled rats were randomly divided into the model group, the Western medicine treatment group (salazosulfapyridine), the treatment from lung group (Huangqi Jiegeng Decoction), and the treatment from intestine group (Huangqi Huanglian Decoction), 8 in each group. Rats in each treatment group were administered with corresponding medication 8 times the dose of a 60 kg adult human. Another 8 normal rats were recruited as the normal group. Equal volume of pure water was given to rats in the model group and the normal group by gastrog avage, once per day. Contents of VIP in the lung tissue and the intestinal tissue were detected at week 0 and 4 after 4-week consecutive intervention. Pathomorphological changes of the lung tissue and the colon tissue were observed under light microscope.

RESULTSCompared with the normal control group at week 0, evenly distributed diffuse inflammation could be seen in the pulmonary interstitial tissue; the bronchial wall was thickened; a huge amount of infiltration surrounded bronchi and blood vessels; a large area of necrosis of intestinal mucosa and inflammatory cell infiltration could also be seen in the model group. Pathological injuries of the lung and the colon were more alleviated in each treatment group than in the model group at the same time point. Compared with the normal control group at the same time point, VIP contents in the lung tissue significantly decreased in the model group at the end of week 4 (P<0.05); VIP contents in the colon tissue significantly increased in the model group at the end of week 0 and 4 (P <0.05). Compared with the model group, VIP contents in the lung tissue significantly increased in the Western medicine treatment group and the treatment from lung group at the end of week 4 (P<0.01); VIP contents in the colon tissue significantly decreased in the treatment from lung group and the treatment from intestine group (P<0.05, P<0.01).

CONCLUSIONTreatment from the lung and treatment from the intestine showed predominant advantage in improving local inflammation of the lung and the intestinal tract, alleviating pathological injuries, promoting repair of injuries through regulating VIP contents in the lung tissue and the colon tissue.

Animals ; Colitis, Ulcerative ; drug therapy ; Drugs, Chinese Herbal ; therapeutic use ; Intestinal Mucosa ; metabolism ; Intestines ; Lung ; Male ; Rabbits ; Rats ; Vasoactive Intestinal Peptide

OBJECTIVE: To determine whether chronic alcoholism alters the expression levels of Vasoactive intestinal polypeptide (VIP) and its receptor (VIPR1) in the cochlea of chronic alcoholism rats. METHOD: We measured their expression levels in 30 SD rats, in which we created models of different degrees of chronic alcoholism. We investigated the presence of the mRNA of VIP in the cochlea of chronic alcoholism rats and controls by reverse transcription-polymerase chain reaction (RT-PCR) method. We investigated the presence of proteins of VIPR1 in poisoned rats and controls by western blot. We also evaluated the local distribution of VIP cells by immunohistochemistry. RESULT: We found that the levels of VIP and VIPR1 were downregulated in the chronic alcoholism groups compared to the controls group. The differences in some expression levels were significant different between chronic alcoholism rats and control rats. Moreover, at different degrees of alcohol poisoning in rats, the contents of VIP and VIPR1 differed. Decreased levels of VIP and VIPR1 were detected in the deep chronic alcoholism group compared to the group with low-degree poisoning (P < 0.05). In spiral ganglion cell plasm the expression of VIP and VIPR1 had no significant difference in three groups (P > 0.05). CONCLUSION These results suggest that VIP and VIPR1 play an important role in the auditory function in rats with chronic alcoholism. Chronic alcoholism may cause a peptide hormone secretion imbalance in the auditory system, eventually leading to hearing loss.
Alcoholism ; metabolism ; Animals ; Cochlea ; metabolism ; Disease Models, Animal ; Down-Regulation ; RNA, Messenger ; Rats ; Rats, Sprague-Dawley ; Receptors, Vasoactive Intestinal Polypeptide, Type I ; metabolism ; Spiral Ganglion ; Vasoactive Intestinal Peptide ; metabolism

To discuss the feasibility of the pharmacodynamic evaluation method for traditional Chinese medicine (TCM) formula particles, with traditional decoction for reference and the intervention of Magnoliae Officinalis Cortex in rats with ulcerative colitis (UC). First of all, the similarity of traditional Magnoliae Officinalis Cortex decoction and formula particles of different manufacturers was defined by using the IR fingerprint. The UC rat model was established and given Houpo formula particles of different doses and manufacturers, with the decoction for reference, in order to observe disease activity index (DAI), colon mucosa damage index (CMDI), pathologic changes, nitric oxide (NO), endothdin (ET), substance P, vasoactive intestinal peptide (VIP). Their intervention effects on UC rats were compared to study the difference between Sanjiu and Tianjiang Houpo formula particles, in order to demonstrate the feasibility of the pharmacodynamic evaluation method for Houpo formula particles. According to the results, Houpo formula particles showed similar pharmacodynamic actions with the traditional decoction. The pharmacodynamic comparison of Houpo formula particles of different manufacturers showed no statistical significance. The experiment showed that on the basis of the TCM compounds, a prescription dismantlement study was conducted to define target points of various drugs. The traditional decoction was selected for reference in the comparison of corresponding formula particles for their pharmacodynamic equivalence. This method could avoid controversies about single or combined boiling of formula particles, and give objective comments on the pharmacodynamic effect of the formula particles. The method is proved to be feasible.
Animals ; Chemistry, Pharmaceutical ; methods ; Colitis, Ulcerative ; drug therapy ; metabolism ; Dosage Forms ; Drug Evaluation, Preclinical ; Drugs, Chinese Herbal ; adverse effects ; chemistry ; pharmacokinetics ; Humans ; Magnolia ; chemistry ; Male ; Rats ; Rats, Wistar ; Substance P ; metabolism ; Vasoactive Intestinal Peptide ; metabolism

OBJECTIVETo study the effect of Jiaweisinisan (JWSNS), a traditional Chinese herbal medicinal recipe, on gastric mucosal ultrastructure and brain-gut axis in rat models of chronic psychological stress and elucidate the mechanism of JWSNS for ameliorating stress-induced gastrointestinal dysfunction.

METHODSSixty rats were randomly assigned into normal control group, model group, 3 JWSNS groups (high, moderate, and small doses), and omeprazole group (n=10). Rat models of chronic psychological stress were established by random stressful stimulations, and following the corresponding interventions, plasma adrenocorticotropic hormone (ACTH) and cortisol (CORT) levels were detected using radioimmunoassay, and the mRNA expressions of gastrin receptor in the gastric tissue (GASR) and vasoactive intestinal peptide II receptor (VIPR2) in the jejunal tissue were examined using RT-PCR. Transmission electron microscopy was employed to examine the ultrastructural changes in the gastric mucosa tissue cells of the glandular stomach area and alterations in the intercellular junctions.

RESULTSElectron microscopy revealed obvious damages in gastric mucosal epithelial cell organelles and nuclei in the model rats. These damages were ameliorated after treatments with JWSNS and omeprazole. Compared with the model group, the 3 JWSNS groups and omeprazole group all showed significantly lowered plasma ACTH and CORT levels, increased gastrin receptor mRNA expression and decreased jejunal VIPR2 mRNA expression (P<0.05 or 0.01).

CONCLUSIONJWSNS can obviously ameliorate the pathologies of the gastric mucosa cells, regulate the state of brain-gut axis, and modulate the gastric gastrin receptor and jejunal VIPR2 mRNA expressions in rats with chronic psychological stress.

Adrenal Cortex Hormones ; blood ; Adrenocorticotropic Hormone ; blood ; Animals ; Drugs, Chinese Herbal ; pharmacology ; Gastric Mucosa ; metabolism ; pathology ; ultrastructure ; Hydrocortisone ; blood ; Jejunum ; metabolism ; Male ; Rats ; Rats, Wistar ; Receptors, Bombesin ; metabolism ; Receptors, Vasoactive Intestinal Peptide, Type II ; metabolism ; Stress, Psychological ; pathology

OBJECTIVETo observe changes of cholecystokinin octapeptide (CCK-8), calcitonin gene related peptide (CGRP), substance P (SP), and vasoactive intestinal peptide (VIP) in each tissue of the digestive system of allergic asthma (AA) model rats.

METHODSThe pulmonary disease (AA) rat model was duplicated by 1% ovalbumin. Its effect on the pathological morphology of the six main parts of the digestive system (stomach, duodenum, jejunum, ileum, colon and rectum) and related regulating factors such as CCK8, CGRP, SP, and VIP were observed.

RESULTSThe pathological morphology of the lung was synchronously changed as that of the colon of model rats. But there was no obvious change in the stomach, duodenum, jejunum, ileum, or rectum. Significant changes occurred in CCK8 (79 961.4 +/- 12 577.9, 48 519.5 +/- 12 240.7), CGRP (41 950.1 +/- 12 600.1, 38 059.8 +/- 11 942.4), and SP (88 243.9 +/- 32 177.2, 47 417.8 +/- 16 462.4), and VIP (20 711.4 +/- 7 334.6, 43 208.1 +/- 13 433.8) of the lung tissue and the colon tissue of model rats (P < 0. 05, P < 0.01). But there was no significant change in the aforesaid substances of the stomach, duodenum, jejunum, ileum and rectum (P > 0.05).

CONCLUSIONSPulmonary disease might affect the colon, inducing pathological changes of the colon tissue and changes of related regulating factors such as CCK8, CGRP, SP, and VIP. It showed no significant effect on the stomach, duodenum, jejunum, ileum and rectum.

Animals ; Asthma ; metabolism ; Calcitonin Gene-Related Peptide ; metabolism ; Colon ; metabolism ; Disease Models, Animal ; Lung ; metabolism ; Male ; Rats ; Rats, Wistar ; Sincalide ; metabolism ; Substance P ; metabolism ; Vasoactive Intestinal Peptide ; metabolism