Alteration of serotonin release response in the central nucleus of the amygdala to noxious and non-noxious mechanical stimulation in a neuropathic pain model rat.

Previously, we found that serotonin (5-HT) release in the central nucleus of the amygdala (CeA) of anesthetized rats decreases in response to innocuous stroking of the skin, irrespective of stimulus laterality, but increases in response to noxious pinching applied to a hindlimb contralateral to the 5-HT measurement site. The aim of the present study was to determine whether intra-CeA 5-HT release responses to cutaneous stimulation were altered in an animal model of neuropathic pain induced by ligation of the left L5 spinal nerve. In anesthetized neuropathic pain model rats, stroking of the left hindlimb increased 5-HT release in the CeA, whereas stroking of the right hindlimb decreased it.

Stroking stimulation of the skin elicits 50-kHz ultrasonic vocalizations in young adult rats.

The present study aimed to clarify if stroking stimulation of the skin produces positive emotion in rats. 50-kHz ultrasonic vocalizations (USVs) were recorded as an index of the positive emotion. Stroking stimulation was applied to the ventral, dorsal, or head region of the body while the rat was in a vertical holding condition.

Somatosensory regulation of serotonin release in the central nucleus of the amygdala is mediated via corticotropin releasing factor and gamma-aminobutyric acid in the dorsal raphe nucleus.

Noxious cutaneous stimulation increases, whereas innocuous cutaneous stimulation decreases serotonin (5-HT) release in the central nucleus of the amygdala (CeA) in anesthetized rats. In the present study, we investigated the contribution of corticotropin releasing factor (CRF) receptors and gamma-aminobutyric acid (GABA) receptors in the dorsal raphe nucleus (DRN) to those responses. Release of 5-HT in the CeA was monitored by microdialysis before and after 10-min stimulation by pinching or stroking.

Serotonin release in the central nucleus of the amygdala in response to noxious and innocuous cutaneous stimulation in anesthetized rats.

We investigated the effect of noxious (pinching) and innocuous (stroking) stimulation of skin on serotonin (5-HT) release in the central nucleus of the amygdala (CeA) in anesthetized rats. 5-HT in the CeA was collected by microdialysis methods. Dialysate output from consecutive 10-min periods was injected into a high-performance liquid chromatograph and 5-HT was measured with an electrochemical detector.

Tickling increases dopamine release in the nucleus accumbens and 50 kHz ultrasonic vocalizations in adolescent rats.

Adolescent rats emit 50 kHz ultrasonic vocalizations, a marker of positive emotion, during rough-and-tumble play or on tickling stimulation. The emission of 50 kHz ultrasonic vocalizations in response to tickling is suggested to be mediated by dopamine release in the nucleus accumbens; however, there is no direct evidence supporting this hypothesis. The present study aimed to elucidate whether play behavior (tickling) in adolescent rats can trigger dopamine release in the nucleus accumbens with hedonic 50 kHz ultrasonic vocalizations.

Therapeutic chaperone effect of N-octyl 4-epi-β-valienamine on murine G(M1)-gangliosidosis.

Therapeutic chaperone effect of a valienamine derivative N-octyl 4-epi-β-valienamine (NOEV) was studied in G(M1)-gangliosidosis model mice. Phamacokinetic analysis revealed rapid intestinal absorption and renal excretion after oral administration. Intracellular accumulation was not observed after continuous treatment.

Tactile skin stimulation increases dopamine release in the nucleus accumbens in rats.

We investigated the effect of mild (non-noxious) tactile stimulation (stroking) of skin on dopamine (DA) release in the nucleus accumbens (NAc) of rats. A coaxial microdialysis probe was stereotaxically implanted in the NAc and perfused with modified Ringer's solution. Dialysate output from consecutive 5-min periods was injected into a high-performance liquid chromatograph and DA was measured using an electrochemical detector.

Electro-acupuncture improves responsiveness to insulin via excitation of somatic afferent fibers in diabetic rats.

The effects of electro-acupuncture (EA) on plasma concentration of glucose and on responsiveness to insulin were examined in an animal model of diabetes, the streptozotocin-treated rat. Two weeks after treatment with streptozotocin, rats were anesthetized with urethane-chloralose and subjected to the EA for 10 min delivered to the tibialis anterior muscle of one side. The stimulation produced no significant changes in plasma glucose concentration.

Responses of dorsal spinal cord blood flow to noxious mechanical stimulation of the skin in anesthetized rats.

In urethane-anesthetized, artificially ventilated rats, alterations in dorsal spinal cord blood flow (SCBF) at the L4-6 level were measured with laser Doppler flowmetry in response to noxious mechanical cutaneous stimulation (pinching) of either a forepaw or a hindpaw. The stimulation was delivered ipsilaterally or contralaterally to the site of blood flow measurement. Pinching of the forepaw or the hindpaw on either side increased mean arterial pressure (MAP) to the same degree.

Chemical chaperone therapy: clinical effect in murine G(M1)-gangliosidosis.

Certain low-molecular-weight substrate analogs act both as in vitro competitive inhibitors of lysosomal hydrolases and as intracellular enhancers (chemical chaperones) by stabilization of mutant proteins. In this study, we performed oral administration of a chaperone compound N-octyl-4-epi-beta-valienamine to G(M1)-gangliosidosis model mice expressing R201C mutant human beta-galactosidase. A newly developed neurological scoring system was used for clinical assessment.

Contribution of supraspinal and spinal structures to the responses of dorsal spinal cord blood flow to innocuous cutaneous brushing in rats.

Responses of dorsal spinal cord blood flow (SCBF) to innocuous mechanical cutaneous stimulation were investigated in anesthetized central nervous system intact (CNS-intact) and C2 spinalized rats. SCBF was recorded at the L4-L6 level with a laser Doppler flowmeter. SCBF increased with brushing of the ipsilateral proximal hindlimb and hindpaw, and there were no significant differences in the magnitudes of the responses in CNS-intact and spinalized animals.

Motor and reflex testing in GM1-gangliosidosis model mice.

A large number of genetic disease model mice have been produced by genetic engineering. However, phenotypic analysis is not sufficient, particularly for brain dysfunction in neurogenetic diseases. We tried to develop a new assessment system mainly for motor and reflex functions in G(M1)-gangliosidosis model mice.

Responses of dorsal spinal cord blood flow to innocuous cutaneous stimulation in anesthetized rats.

In urethane-anesthetized, artificially-ventilated rats, alterations in dorsal spinal cord blood flow (SCBF) were measured with a laser Doppler flowmeter in response to innocuous mechanical cutaneous stimulation. SCBF recorded at the T12-L1 level increased with brushing of the ipsilateral, but not contralateral, upper back, lower back or proximal hindlimb. Brushing of the forepaw, proximal forelimb or hindpaw had no effect on T12-L1 SCBF.

Ovarian blood flow responses to electroacupuncture stimulation depend on estrous cycle and on site and frequency of stimulation in anesthetized rats.

Electroacupuncture (EA) applied to the abdomen and hindlimb modulates the ovarian blood flow (OBF) response. The present study aimed to further elucidate the role of the site and the frequency of short-term EA stimulation and the influence of the estrous cycle on the OBF response using anesthetized rats. EA stimulation was applied to the abdominal or the hindlimb muscles at three different frequencies (2, 10, and 80 Hz) during the estrus or diestrus phase.

Responses of hepatic glucose output to electro-acupuncture stimulation of the hindlimb in anaesthetized rats.

Responses of hepatic glucose output (HGO) to electro-acupuncture (EA) stimulation of the hindlimb were investigated in anaesthetized rats, focusing on involvement of the somatic afferent and autonomic efferent nerves. HGO was measured with a microdialysis probe implanted into the left lateral lobe of the liver. Stainless steel needles with a diameter of 0.

Cholecystokinin and prostaglandins inhibit responses of vagal afferent activity to systemic administration of nicotine in anesthetized rats.

Systemic administration of nicotine suppresses food intake. Since gastric vagal afferents convey satiation signals to the hypothalamus in response to cholecystokinin, we investigated the possibility that nicotine increases afferent activity of the gastric vagal nerves by stimulating release of cholecystokinin. Furthermore, involvement of prostaglandins in the responses of gastric vagal afferents to nicotine was also investigated because prostaglandins stimulate gastric vagal afferent activity.

Intraportal nicotine infusion in rats decreases hepatic blood flow through endothelin-1 and both endothelin A and endothelin B receptors.

Smoking has been demonstrated to aggravate liver injury. Nicotine, a major pharmacological component of tobacco smoke, affects a multitude of functions. Smoking and nicotine induce synthesis of endothelin (ET)-1.

Effect of electro-acupuncture stimulation of different frequencies and intensities on ovarian blood flow in anaesthetized rats with steroid-induced polycystic ovaries.

Background: Maintenance of ovarian blood flow (OBF) is suggested to be important for regular ovulation in women with polycystic ovaries (PCO). The purpose of the present study was to investigate whether electro-acupuncture (EA) of different frequencies and intensities can improve the OBF of anaesthetized rat in the animal model of PCO.

Methods: PCO was experimentally induced by a single intramuscular (i.

Central administration of ghrelin stimulates pancreatic exocrine secretion via the vagus in conscious rats.

Ghrelin, a novel growth-hormone releasing peptide, was originally isolated from rat and human stomach. Immunohistochemical analyses revealed that ghrelin-immunoreactive neurons were localized in the hypothalamic arcuate nucleus. The function of the digestive organs is controlled from the central nervous system, and the vagus nerve plays an important role.

Ovarian blood flow responses to electro-acupuncture stimulation at different frequencies and intensities in anaesthetized rats.

The purpose of the present study was to investigate changes in ovarian blood flow (OBF) in response to electro-acupuncture (EA) stimulation at different frequencies and intensities in anaesthetized rats. Whether the ovarian sympathetic nerves were involved in OBF responses was elucidated by severance of the ovarian sympathetic nerves. In addition, how changes in the systemic circulation affected OBF was evaluated by continuously recording blood pressure.

Lafutidine increases hepatic blood flow via potentiating the action of central thyrotropin-releasing hormone in rats.

Background: Lafutidine, (+/-)-2-(furfurylsulfinyl)-N-[4-[4-(piperidinomethyl)-2-pyridyl]oxy-(Z)-2 butenyl]acetamide, is a newly synthesized histamine H2 receptor antagonist and possesses a cytoprotective efficacy, which comprises mucin biosynthesis and stimulation of gastric blood flow mediated through capsaicin-sensitive sensory neurons and endogenous calcitonin gene-related peptide (CGRP). In the present study, an effect of lafutidine on hepatic blood flow was investigated in rats that received an intracisternal injection of a subthreshold dose of thyrotropin-releasing hormone (TRH) analog, RX 77368.

Methods: Change in hepatic blood flow was determined by laser Doppler flowmetry.

Responses of hepatic glucose output to noxious mechanical stimulation of the skin in anaesthetised rats.

Responses of hepatic glucose output (HGO) to noxious mechanical stimulation of different skin areas were investigated in anaesthetised rats with central nervous system intact or acutely spinalized at the thoracic 1-2 (T1-T2) level by focusing on the involvement of the sympathetic and parasympathetic nerves in the responses of HGO. We measured HGO with a microdialysis probe implanted into the left lateral lobe of the liver. Pinching was applied to bilateral skin areas of the abdomen and hindlimb for 10 min.

Central Orexin-A stimulates pancreatic exocrine secretion via the vagus.

Introduction: Digestive organs are controlled from the central nervous system, and the vagus nerve plays an important role. Orexins are recently purified neuropeptides localized in neurons within the lateral hypothalamus.

Aim: To examine the effects of centrally injected Orexin-A and B on pancreatic exocrine secretion in conscious rats.