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.

Quantitative analysis of the distribution of the myenteric plexus in the rabbit large intestine.

Rabbit large intestine has a segment-specific morphology and motility. However, the morphological features of the myenteric plexus, which controls intestinal motility, have not been characterized in each large intestinal segment. We investigated the myenteric plexus morphology in the rabbit large intestine using protein gene product 9.

Arterial branching pattern of the cranial mesenteric artery in the degu (Octodon degus).

Background: The cranial mesenteric artery exhibits a species-specific ramification pattern that adapts to the morphology of the intestinal tract. The degu is a strictly herbivorous rodent with a well-developed large intestine with a spiral loop in the ascending colon; therefore, the cranial mesenteric artery likely demonstrates a degu-specific ramification pattern. Thus, we traced the cranial mesenteric artery to establish the detailed ramification pattern of the branches.

Comparison of the retrosplenial cortex size between the degu (Octodon degus) and the Wistar rat (Rattus norvegicus).

The degu (Octodon degus) is a rodent that normally constructs burrows for nesting and rearing. To navigate inside these burrows, degus may use idiothetic and/or sensory cues more than visual information, which is less effective in burrows. Spatial information for navigation is processed in several key brain regions including the retrosplenial cortex (RS).

Branching patterns of the adrenal arteries in the degu (Octodon degus).

The degu has drawn increasing attention for use as an experimental animal in stress response studies due to its physiological features, such as diurnality and seasonal breeding, which differ from conventional laboratory rodents. Stress response is elicited by steroid hormones secreted by the adrenal gland, whose functions are controlled by pituitary hormones reaching through the adrenal arteries. However, knowledge of the arterial anatomy of the degu adrenal gland remains insufficient.

Arterial supply to the rat colon.

Rats are often used as animal models in studies such as on intestinal transplantation and anastomosis healing, which require colectomy. Although detailed information regarding arterial supply is important to establish accurate and reproducible experimental procedures, this has not been studied in the rat colon. Therefore, we analysed the detailed arterial distribution pattern and its individual variations in the colon of 34 rats.

Simultaneous antagonism of dopamine D1/D2/D3 receptor in the NAc reduces 50-kHz ultrasonic calls in response to rhythmic tactile stroking.

Tactile stimulation such as rhythmic stroking elicits 50-kHz ultrasonic vocalizations (USVs) in rats that are thought to reflect positive affective states. Dopaminergic neurotransmission in the nucleus accumbens (NAc) is required for tactile reward-induced 50-kHz USVs; however, it is still unknown whether the accumbal dopaminergic system differentially modulates 50-kHz USV call subtypes induced by rhythmic stroking. We therefore examined both total and categorized 50-kHz USV rate, peak frequency, and duration under dopamine (DA) receptor antagonism in the NAc shell.

Arterial branching pattern of the rabbit femoral artery.

Rabbits have highly developed hindlimb muscles, whereas their bones are fragile, thus resulting in frequent hindlimb fractures. To repair these fractures, it is important to understand the arterial branching pattern of the femoral artery, as it provides the main blood supply to the hindlimb. Since the descriptions from prior studies are insufficient, the aim of the present study was to determine the detailed arterial branching pattern of the rabbit femoral artery.

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.

Arterial supply to the rabbit male genital organs.

The improvement of veterinary care has prolonged the lifespan of rabbits, and the number of rabbits suffering from age-related, male genital disorders may increase in the near future. This could result in increased opportunities for male genital surgery, requiring knowledge of their arterial anatomy, which, however, has not been sufficiently studied. Therefore, the arteries supplying the genitals were observed in 20 male New Zealand White rabbits.

A case report of a rare ramification pattern and distribution area of the mesenteric arteries in a Japanese White rabbit (Oryctolagus cuniculus).

The rabbit intestinal tract is supplied by the cranial and caudal mesenteric arteries. Generally, the cranial mesenteric artery supplies the duodenum, jejunum, ileum, cecum, proximal colon and ascending and transverse distal colon, whereas the caudal mesenteric artery supplies the descending distal colon and rectum. The present study describes an abnormal branching pattern of the cranial and caudal mesenteric arteries in a Japanese White rabbit, where the caudal mesenteric artery but not the cranial mesenteric artery supplied the distal ileum, cecum, proximal colon and ascending and transverse distal colon.

Distribution of neuronal structures immunoreactive for parvalbumin in the midcingulate cortex of the rabbit.

The rabbit midcingulate cortex that enclosed four cortical areas was immunohistochemically studied using a calcium-binding protein, parvalbumin, as a neurochemical marker. The distribution of parvalbumin-immunopositive somata and fibres was similar across all four areas, where they were present mainly in layers 2/3 and 5. However, there were a slightly greater number of the immunopositive structures in the two ventral areas than the two dorsal areas.

Ramification Pattern of the Arteries Supplying the Rabbit Female Genital Organs.

Uterine adenocarcinoma occurs in more than 60% of female rabbits aged 4 years and over. To cure or prevent this uterine disorder, ovariohysterectomy should be performed. Although knowledge of the arterial supply to the ovary, uterus, and vagina is required, few studies have described the arterial anatomy.

Wall thickness and mucous cell distribution in the rabbit large intestine.

To achieve a better understanding of rabbit large intestinal functions, such as production of hard and soft feces and cecal fermentation, knowledge of the intestinal wall structure is essential. However, such knowledge is far from complete. Therefore, the aims of this study were to measure the thickness of the wall and its constituent layers and describe distribution of mucous cells in each segment of the large intestine in New Zealand White rabbits.

Distribution of calretinin immunopositive somata and fibers in the rabbit midcingulate cortex.

The midcingulate cortex (MCC; area 24') resides in the mid-rostrocaudal part of the cingulate gyrus, and it plays important roles in nociceptive, cognitive and skeletomotor functions. The MCC has recently been shown to consist of four cortical areas (areas a24a', a24b', p24a' and p24b') in the rabbit, based on immunohistochemistry. To further characterize the organization of these areas, here we immunohistochemically identified structures immunopositive (+) for calretinin (CR) as a marker of a subpopulation of inhibitory neurons.

Anatomical variations of the arterial branches from the rat iliac arteries.

Animal disease models contribute to a better understanding of the pathogenic mechanisms of human and animal diseases and help develop treatments for them. Ligation of the rat iliac arteries is performed to reproduce erectile dysfunction and peripheral arterial disease. Although knowledge of the ramification of branches from the rat iliac artery is important to perform such surgery, descriptions in previous studies are insufficient.

Arterial supply to the rabbit adrenal gland.

The adrenal gland regulates stress responses by releasing steroid hormones, whose synthesis and secretion are influenced by adrenal blood flow. Adrenalectomy is commonly performed in rabbits to study the function of the adrenal gland. Although knowledge of the arterial supply to the adrenal gland forms the anatomical basis of the surgery, its description in prior studies is incomplete for the rabbit.

Organizational connectivity among the CA1, subiculum, presubiculum, and entorhinal cortex in the rabbit.

The laminar and topographical organization of connections between the hippocampal formation and parahippocampal regions was investigated in the rabbit following in vivo injection of cholera toxin B subunit as a retro- and antero-grade tracer and biotinylated dextran amine as an anterograde tracer. We confirmed several connectional features different from those of the rat, that is, the rabbit presubiculum received abundant afferents from CA1 and had many reciprocal connections with the entorhinal cortex. On the other hand, we identified many similarities with the rat: both the CA1 and subicular afferents that originated from the entorhinal cortex were abundant; moreover, the presubiculum received many inputs from the subiculum and sent massive projections to the entorhinal cortex.

Macroscopic anatomical study of the distribution of the cranial mesenteric artery to the intestine in the rabbit.

Intestinal surgery is commonly performed to cure bowel obstruction in rabbits, but detailed descriptions of the arterial supply to the intestine are incomplete. We investigated anatomical variations of the distribution of the cranial mesenteric artery to the intestine in 33 New Zealand White rabbits by injecting colored latex into the arteries. The cranial mesenteric artery arose independently from the abdominal aorta at about 2.

Anatomical variations of the arterial supply to the adrenal gland in the rat.

The adrenal gland is an essential endocrine organ for the stress response. The functions of this organ may be studied by ligation of the adrenal artery or adrenalectomy. However, in prior studies, descriptions of the anatomical variations of the adrenal artery were insufficient and inconsistent.

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.

Anatomical variation of arterial supply to the rabbit stomach.

Gastric stasis is common in rabbits, and gastrotomy may be performed to cure this pathological condition. Detailed descriptions of the arterial supply to the stomach are essential for this surgical operation, but published descriptions are limited. Here, we investigated anatomical variations of the arterial supply to the stomach in 43 New Zealand White rabbits by injecting colored latex into arteries.

Anatomical variation of arterial supply to the rabbit spleen.

The rabbit, which is widely used as an experimental animal and is also popular as a companion animal, has a flat and elongated spleen with the longitudinal hilus running along its visceral surface. The spleen receives via the hilus an arterial supply that is essential for splenic nutrition and normal functioning. However, the distribution and variation of the arteries to the spleen have not been studied in detail.

Thalamocortical projections of the anteroventral thalamic nucleus in the rabbit.

The anterior thalamic nuclei are one of the regions that play critical roles in behavioral learning and memory functions. A part of the anterior thalamic nuclei, the anteroventral nucleus (AV) is well developed and differentiated into the parvocellular (AVp) and magnocellular (AVm) division in the rabbit. The AV is crucial for learning discriminative avoidance conditioning.