Furthermore, animals treated with binge MDMA (Experiment 2) showed a striking decrease in SERT gene expression (and a lesser effect on VMAT-2) measured by quantitative RT-PCR in pooled dorsal and median raphe tissue punches, when compared to saline-treated controls. 
Separation also selectively increased 5-hydroxytryptamine turnover in the hippocampus and median raphe nucleus. It is suggested that the increase in anxiety determined by both acute and chronic stress is mediated by the activation of the median raphe nucleus-hippocampal 5-hydroxytryptamine pathway..
Division of the median raphe of the neck muscles was followed by exposure of the thyroid gland.
Selective stimulation of serotonergic median raphe neurons produced a rapid activation of hippocampal interneurons.
Summary median raphe cysts are an uncommon dermatology. Even more uncommon is their presentation as a cordlike or canaliform induration in the median raphe, confusingly called a median raphe cyst. Two such cases are reported in children, and the term 'canaliform median raphe cysts' is suggested..
OBJECTIVES: To report 2 cases of median raphe cysts, 1 in the penis and the other in the perineum. METHOD: Two cases of median raphe cyst are described; the first was treated by surgery and the second required no treatment. CONCLUSIONS: median raphe cysts are a rare, benign condition of uncertain etiology.
SB 242084 also completely blocked the LPS-induced increases in c-Fos expression in the paraventricular nucleus, central nucleus of the amygdala, nucleus tractus solitarii, median raphe nucleus and dorsal raphe nucleus and partially blocked it in the A1 noradrenergic area of the ventrolateral medulla and the raphe pallidus nucleus.
Significant differences in regional oxidative metabolic activity as measured by cytochrome c oxidase (COX) histochemistry were found between male and female rats: Females had lower oxidative metabolism in several brainstem areas such as dorsal and median raphe and pontine nucleus, some cortical areas, and reward-related forebrain regions such as striatum and nucleus accumbens, but higher oxidative metabolism in amygdala and related limbic regions.
However, there were some areas where neurons containing these two proteins were separate populations including the cerebral cortex and median raphe nucleus.
This study evaluated the effect of intra-median raphe nucleus (MRN) microinjection of 1,3,7-trihydroxy-2-(3-methylbut-2-enyl)-xanthone, present in large quantity in the HE from Kielmeyera coriacea stems, on immobility behaviour in the FST in rats.
At PD70, changes in glucose metabolism were restricted to specific systems, such as the auditory system, the cerebellum, the serotonergic median raphe, and median septum.
Estrogen receptors have been identified in the median raphe nucleus (MRN).
Independent studies have shown that the median raphe nucleus (MRN) and dorsal hippocampus (DH) are involved in the expression of contextual conditioned fear (CFC).
Exposure of rats to unpredictable loud sound pulses increases activity of the rate-limiting enzyme for serotonin synthesis, tryptophan hydroxylase (TPH), in the median raphe nucleus (MnR) and a mesolimbocortical serotonergic system.
In "depressed" FSL rats, citalopram produced a significant (p < 0.05) elevation of synthesis in seventeen out of thirty-four regions, with a significant (p < 0.05) reduction in the dorsal and median raphe.
The medial prefrontal cortex (mPFC) controls emotional responses in many species, receiving serotonergic innervation from the dorsal and median raphe nucleus (DRN and MRN).
Histological and immunohistological features were not consistent neither with median raphe cysts or cutaneous adenomas nor with the intrascrotal adenomas of the rete testis, epididymis, nor with (malignant) mesotheliomas.
Oxytocin infusion facilitated serotonin release within the median raphe nucleus and reduced anxiety-related behavior.
In the present study, we have used unbiased stereological procedures to estimate the number of the dorsal and median raphe nuclei (DRN and MRN, respectively) serotonergic neurons immunolabeled with an anti-tryptophan hydroxylase (TrH) monoclonal antibody in young and aged dogs without A beta cortical deposits and in aged dogs with A beta cortical deposits.
In the present study, we examined the changes in the firing rate and firing pattern of the dorsal and median raphe nuclei (DRN and MRN) 5-HT neurons, and the effect of the selective 5-HT(1A) receptor agonist (R)-(+)-8-hydroxy-2-(dipropylamino)tetralin hydrobromide (8-OH-DPAT) and antagonist (N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-2-pyridylcyclohexane carboxamide maleate salt (WAY-100635) on the neuronal firing in rats with 6-hydroxydopamine (6-OHDA) lesions of the substantia nigra pars compacta by using extracellular recording.
Pet-1 and 5-HTT mRNA levels were quantified throughout the dorsal and median raphe nuclei (DRN and MRN) by conducting in situ hybridization on free-floating tissue sections using (35)S-labeled cDNA probes.
In the FSL rats, there were reductions in some brain regions (e.g., dorsal and median raphe, amygdala, anterior olfactory nucleus, substantia nigra reticulate), while in other regions, there were increases in the synthesis observed (e.g., frontal, parietal, visual and somatosensory cortices, ventral hippocampus).
In OBX rats, citalopram decreased synthesis at a few terminal regions and greatly decreased synthesis at the dorsal and median raphe ( approximately 45%; relative to OBX rats treated with saline).
Concurrently, this stimulus suppressed SCN activity while activating cells in the median raphe.
Unexpectedly, FEV-LacZ transgenes enabled determination of 5-HT neuron precursor fate in the adult Pet-1(-/-) dorsal and median raphe nuclei and thus provided additional insight into FEV/Pet-1 function.
GHB (500 mg/kg), but not baclofen (10 mg/kg), induced significant Fos expression in the median raphe nucleus and lateral habenula, while a higher dose of GHB (1000 mg/kg) induced additional Fos expression in the islands of Calleja, dentate gyrus (polymorphic layer) and arcuate nucleus, and in various regions implicated in rapid and non-rapid eye movement sleep (laterodorsal tegmental nucleus, tuberomammillary nucleus and the ventrolateral and anterodorsal preoptic nuclei).
The present study examined the effects of local injections of adrenaline (AD) or noradrenaline (NA) in equimolar doses (6, 20, and 60 nmol) into the median raphe nucleus (MRN) on ingestive and non-ingestive behaviors of free-feeding rats.
Repair is based on a vertical incision in median raphe, complete degloving of penis and tacking its base to prepubic fascia.
The median raphe of the penis may be normal and mask unexpected glans torsion. median raphe torsion at foreskin tip can be used as a predictor for glans torsion.
Recent studies have reported that the vesicular glutamate transporter VGLUT3 is found in both serotonergic and nonserotonergic neurons in both the median raphe (MR) and dorsal raphe (DR) nuclei.
In the present work, we have described the effects of serotonin (5-HT) depletion after the administration of 5,7-dihydroxytryptamine (5,7-DHT) into the median raphe nucleus in rats submitted to the pilocarpine model of epilepsy.
Changes in 5-HT1A receptor-mediated neurotransmission at the level of the median raphe nucleus (MRN) are reported to affect the expression of defensive responses that are associated with generalized anxiety disorder (e.g.
Infusions of CRF (0.5 microg/0.5 microL) were made into the dorsal raphe nucleus of urethane-anesthetized rats following either inactivation of the median raphe nucleus by muscimol (25 ng/0.25 microL) or antagonism of CRF receptor type 1 or CRF receptor type 2 in the dorsal raphe nucleus with antalarmin (25-50 ng/0.5 microL) or antisauvagine-30 (2 microg/0.5 microL), respectively. Increased medial prefrontal cortex serotonin release elicited by CRF infusion into the dorsal raphe nucleus was abolished by inactivation of the median raphe nucleus.
The reduced synthesis was also observed in the dorsal raphe (DR) nucleus and the median raphe (MR) nucleus.
We present an overview of our studies on the differential role of serotonergic projections from the median raphe nucleus (MRN) and dorsal raphe nucleus (DRN) in behavioural animal models with relevance to schizophrenia.
Further evidence for CB(1) involvement in hamster circadian rhythms was provided by immunohistochemical detection of CB(1) receptors in four separate nuclei comprising the principal components of the hamster circadian system: the suprachiasmatic nucleus, intergeniculate leaflet of the thalamus, and dorsal and median raphe nuclei.
The following thirteen regions were identified by the stepwise discriminant analysis of the z-scores as significantly contributing to the differences between the sham and OBX: amygdala, cingulate cortex, caudate putamen at the level of globus pallidus, caudate putamen-lateral part, dorsal subiculum, dorsal thalamus, hypothalamus, median raphe, somatosensory cortex, substantia nigra, ventral hippocampus, ventral tegmental area and the ventral thalamus.
Microdissection revealed that only human specimens had a muscle originating from the anterior arch of the cricoid cartilage, and coursing between the inferior pharyngeal constrictor and cricopharyngeus muscles to insert into the median raphe at the posterior midline of the pharynx.
This was done by testing the effect of systemic blockade of 5-HT-1A receptors on Fos expression in 5-HT neurons in the dorsal raphe (DR) and median raphe (MR).
Mice received stereotaxic micro-injections of the serotonin neurotoxin 5,7-dihydroxytryptamine into the median raphe nucleus (MRN).
Evidence has accumulated suggesting that the median raphe (MR) mediates hippocampal theta desynchronization.
All patients were treated by insertion of an intracavernous cuff according to the same technique: perineoscrotal incision on the median raphe, dissection of the bulbar urethra and inferior aspect of the corpora cavernosa, vertical incision of the tunica albuginea on either side of the urethra, passage of the cuff from one incision to the other behind the tunica albuginea and leaving the tunica albuginea against the urethra, and closure of the tunica albuginea by interrupted sutures leaving a passage for the cuff.
In the present study, we examined the role of corticotropin releasing factor (CRF) in the median raphe nucleus (MRN) on fear-related behaviors in rats.
median raphe cysts of the perineum are uncommon congenital lesions of the male genitalia.
Transient increases followed by decreases were detected in 5-HTT mRNA expression of dorsal and median raphe nuclei at 7 d and 21 d after the treatment.
This study explored the putative role of the principal 5-hydroxytryptamine (5-HT) neurones that project to the hippocampus from the median raphe nucleus in this response to an aversive environment by lesioning the 5-HT fibres that project through the fornix/fimbria and cingulum bundles. It is concluded that exposure to an explicitly aversive environment elicits a brief stimulation of the 5-HT neurones that project to the hippocampus from the median raphe nucleus and that this stimulation inhibits the initial burst of exploratory activity that is observed in animals placed in a less aversive novel environment..
rats with duration of a freezing response one standard error, or more, below the mean value, had a higher activity of the M2 cortical area, and the median raphe nucleus (c-Fox expression), in comparison to the high responders (HR), i.e.
The effect of CRF on behavior and on the accompanying change in activity of 5-HT neurons in the dorsal and median raphe nuclei (DR and MR) that project to the ventral medial prefrontal cortex (mPFC), a brain area implicated in mood and anxiety disorders, was studied.
RATIONALE AND OBJECTIVES: We previously found that the inhibition of median raphe nucleus (MRN) 5-HT transmission by local injections of a 5-HT1A agonist 8-OH-DPAT or corticotrophin-releasing factor (CRF) mimic the effect of foot shock stress to reinstate alcohol seeking.
Rats were implanted with a monopolar stimulation electrode aimed at the lateral hypothalamus, ventral tegmental area, dorsal raphe or median raphe nuclei, and a lesioning electrode in the ipsilateral habenula.
The present study was undertaken to elucidate whether early postnatal stress affects rat brain development and influences the serotonergic function in the midbrain median raphe nuclei (MRN) and dorsal raphe nuclei (DRN) in the adult, focusing on the response to unconditioned fear stress.
These systems are afferents originating from the medial septum/diagonal band of Broca GABAergic and cholinergic neurons, neurochemically distinct types of neurons located in the supramammillary area, serotonergic fibers from the median raphe, noradrenergic afferents from the pontine nucleus, locus ceruleus, dopamine axons originating in the ventral tegmental area, and the commissural projection system.
We evaluated the involvement of dorsal hippocampus (DH) 5-HT1A receptors in the mediation of the behavioral effects caused by the pharmacological manipulation of 5-HT neurons in the median raphe nucleus (MRN).
RESULTS: A decrease in serotonin transporter density was detected in some frontal rat brain areas, and an increase in serotonin transporter density was detected in the right median raphe nucleus.
A low tryptophan diet led to decreases in plasma tryptophan levels, low ratio of tryptophan/large neutral amino acid, whole blood 5-HT, and neuronal 5-HT content in the Dorsal and median raphe Nuclei, as well as altered c-fos expression in the brain.
Serial sections were immunostained for tryptophan hydroxylase (TrOH) and alpha-synuclein and cell counts were performed in the dorsal raphe (DR), median raphe (MR) and medullary raphe nuclei.
The effect of the equimolar doses (6, 20 and 60 nmol) of either adrenaline (AD) or noradrenaline (NA) microinjected into the median raphe nucleus (MR) on feeding behavior of food-restricted rats (15 g/day/rat) was investigated.
median raphe cyst is a very rare, benign congenital lesion occurring mainly on the ventral aspect of the penis, but can develop anywhere in the midline between the external urethral meatus and anus. We report a case of median raphe cyst in the perineum presenting as a perianal polyp in a 65-year-old, English white male with exceptionally rare ciliated epithelium. According to our knowledge, this is the third such case of ciliated median raphe cyst in the English literature. This case, also the first case of ciliated median raphe cyst in the perineum location, focuses on pathogenesis of median raphe cyst..
Finally, we also describe median raphe nucleus double-labeled cells (DY+TB) signaling diffuse descending projections for this largely studied nucleus that are involved in endogenous analgesia..
Tryptophan hydroxylase (TPH, the rate-limiting enzyme of serotonin synthesis) protein and mRNA levels display a circadian expression in the rat dorsal and median raphe. In the absence of adrenals, a complete suppression of Tph2 mRNA rhythm was observed in dorsal and median raphe over 24 h. In conclusion, both endocrine and behavioral cues can modulate Tph2 expression in dorsal and median raphe.
The present study was carried out to assess the influence of noradrenergic stimulation of the midbrain dorsal (DRN) and median raphe nuclei (MRN) on urinary volume and electrolyte excretion in hydrated rats.
However, there was no significant influence on the 5-HT synthesis rate in the dorsal and median raphe nuclei and the majority of their projection areas.
The olfactory rosette is an oval structure composed of a number of lamellae arranged on a median raphe.
Here, we used extracellular single unit recording in midbrain slices to examine glutamate receptor mediated effects on 5-HT neuronal activity in the dorsal raphe nucleus (DRN) and the median raphe nucleus (MRN).
To this effect, it is strongly wired to more rostral and caudal areas, in particular the brainstem periaqueductal grey, the locus coeruleus and the median raphe nuclei, all involved in autonomic and sleep mechanisms and also in the descending control of pain perception.
Congenital retinal macrovessel is a large aberrant vessel, often unilateral, usually a vein, rarely an artery, located in the posterior pole which can cross the fovea and median raphe..
5-HT immunoreactivity in the dorsal raphe nucleus and the median raphe nucleus was also similarly detected in both animal groups.
In search for functional polymorphisms within the TPH2 gene locus, we measured allele-specific expression of TPH2 mRNA in sections of human pons containing the dorsal and median raphe nuclei.
There was no difference between control and BDNF knockout mice in 5-HT1A receptor number or function in the dorsal or median raphe nuclei or medial prefrontal cortex or anterior cingulate cortex. Corticosterone treatment of control mice decreased 5-HT1A receptor function in the dorsal and median raphe but not in hippocampus or frontal cortical areas. The regulation of 5HT1A receptor number or function in the dorsal and median raphe by corticosterone was lost in BDNF knockout mice.
The present results suggest that median and dorsal raphe neurons presumably inhibited by muscimol via GABA(A) receptors are involved in integration of primary reinforcement, and that median raphe neurons exert tonic inhibition over dopamine-dependent reward circuitry.
Taking into account that neural sympathetic activity is positively correlated to the A5 noradrenergic nucleus and median raphe serotonergic neurons, and negatively correlated to the A6 noradrenergic, the dorsal raphe serotonergic and the C1 adrenergic neurons, we postulate that this unbalanced central nervous system circuitry is responsible for the hyperinsulinism syndrome..
We postulated that EH depends on the predominance of the binomial A5 noradrenergic (NA) nucleus + median raphe serotonergic (5-HT) nucleus over the (A6)-NA + dorsal raphe-5HT nuclei.
Voluntary ethanol consumption altered mu-opioid receptor function in the cingulate cortex, caudate-putamen (CPu), nucleus accumbens core (Acb C) and shell (Acb S), the expression of tyrosine hydroxylase (TH) in the ventral tegmental area and substantia nigra, proenkephalin (PENK) in the piriform cortex, olfactory tubercle, CPu, Acb C and Acb S, ventromedial nucleus (VMN) and paraventricular nucleus (PVN) of the hypothalamus, corticotropin releasing factor (CRF) in PVN, cannabinoid CB(1) receptor (CB1-R) in the CPu, hippocampus and VMN, and serotonin transporter (5-HTT) in the dorsal and median raphe nuclei.
The dorsal and median raphe nuclei housing the main serotonergic cell bodies and the prefrontal cortex (PFC), particularly the ventral part innervated by the serotonergic system, have therefore been studied extensively in suicidal behavior research.
Genital examination showed diffuse papulonecrotic skin ulcers involving the whole penile shaft, extending ventrally to the median raphe of the scrotum.
In addition, pathways from the dorsal and median raphe (DR and MR) convey arousal state information to the IGL and SCN, respectively.
Most serotonergic innervation of the forebrain arises from the median raphe nucleus (MRN) and dorsal raphe nucleus (DRN).
Serotonin 1A (5-HT1A) receptors are distributed throughout the brain with their highest concentrations in the frontal cortex, subthalamic nucleus and entopeduncular nucleus as well as the dorsal and median raphe nucleus.
All patients were treated using a standardized and integrated surgical technique, which included resection of the median raphe or leaflet plication, subcommissural annuloplasty, reinforcement of the leaflet free edge, and sinotubular junction plication.
Orexin (hypocretin)-containing neurons in the perifornical hypothalamus project to widespread regions of the brain, including the dorsal and median raphe nuclei [ Peyron C, Tighe DK, van den Pol AN, de Lecea L, Heller HC, Sutcliffe JG, Kilduff TS (1998) Neurons containing hypocretin (orexin) project to multiple neuronal systems. Orexin-A or orexin-B was infused by reverse microdialysis into the dorsal raphe nucleus or median raphe nucleus of freely behaving rats, and extracellular serotonin was simultaneously collected by microdialysis and analyzed by high-performance liquid chromatography. We have found that orexin-A produced a dose-dependent increase of serotonin in the dorsal raphe nucleus, but not in the median raphe nucleus. However, orexin-B elicited a small but significant effect in both the dorsal raphe nucleus and median raphe nucleus.
To this effect, it is strongly wired to more rostral and caudal areas, in particular the brainstem periaqueductal grey, the locus coeruleus and the median raphe nuclei, all involved in sleep mechanisms and also in the descending control of pain perception.
Visual field examination revealed decreased retinal sensitivities in the areas within the visual field arches above and below fixation from the blind spot to the median raphe, corresponding to the arcuate retinal nerve fibers comprising the Bjerrum areas and the area corresponding to the retinal artery occlusion.
The mesencephalic dorsal and median raphe nucleus (DRN; MRN) and three prosencephalic areas closely related to cognitive abilities (CA1 hippocampal area, striatum and frontal cortex) were studied by digital image analysis.
The hypothalamic suprachiasmatic nucleus (SCN) is a circadian oscillator that receives a dense serotonergic innervation from the median raphe nucleus.
5-HT neurones in the median raphe nucleus (MRN) are involved in anxiety and the sleep/wake cycle.
RATIONALE AND OBJECTIVES: We previously found that systemic injections of the 5-HT uptake blocker fluoxetine attenuate intermittent footshock stress-induced reinstatement of alcohol seeking in rats, while inhibition of 5-HT neurons in the median raphe induces reinstatement of alcohol seeking.
The aim of this study was to investigate possible role of 5-HT(1A) and 5-HT(2) receptors in dorsal and median raphe nucleus on development of tolerance to analgesic effect of morphine using hot plate test. Chronic injection of 5-HT(1A) receptor agonist 8-OH-DPAT (8-hydroxy-2-[ di-n-propylamino]tetralin) (2, 4 and 8 mug/rat/day) to dorsal raphe nucleus (DRN) delayed tolerance to morphine analgesia, whereas injection of the same doses of 8-OH-DPAT to the median raphe nucleus (MRN) did not alter tolerance to morphine.
Brainstem serotonergic systems in the dorsal raphe nucleus and median raphe nucleus may be part of a distributed neural system that, together with the basolateral amygdala, regulates acute and chronic anxiety states. We therefore investigated the effect of an acute bilateral injection of urocortin 1 into the basolateral amygdala on behavior in the social interaction test and on c-Fos expression within serotonergic neurons in the dorsal raphe nucleus and median raphe nucleus. In home cage rats and rats exposed to the social interaction test, urocortin 1 treatment increased the number of c-Fos-immunoreactive serotonergic neurons within subdivisions of both the dorsal raphe nucleus and median raphe nucleus.
Therefore, we examined the effects of estrogen and progesterone on TPH2 mRNA in the rat dorsal and median raphe nuclei (DRN and MRN, respectively) and whether TPH2 mRNA levels correlated with anxiety behavior.
LTP was also blocked in anesthetized animals by direct application of WAY to the dentate gyrus, but not to the median raphe nucleus (MRN), suggesting the effect of systemic WAY is mediated by a block of dentate 5-HT1a receptors.
In the present review, we cite and present evidence supporting the dorsal raphe versus median raphe serotonergic circuitry as one model of a reliable paradigm, necessary to the clear understanding and therapy of many psychiatric and even non-psychiatric disturbances..
We have used analysis of allelic expression imbalance (AEI) of SERT mRNA to assess quantitatively the contribution of SERTLPR to mRNA expression in human post-mortem pons tissue sections containing serotonergic neurons of the dorsal and median raphe nuclei.
In male Sprague-Dawley rats, selected parts of the brain 5-HT systems were lesioned by micro-injection of the 5-HT neurotoxin 5,7-dihydroxytryptamine into the dorsal raphe nucleus (DRN) or median raphe nucleus (MRN).
Cysts of the median raphe are uncommon.
Our results showed an increase in the number of c-Fos immunoreactive nuclei in serotoninergic cells in both dorsal and median raphe nuclei in the immobilized group.
Mouse Ucn 2 had no effect on c-Fos expression within the median raphe nucleus, consistent with the hypothesis that Ucn 2 has specific actions on an anatomically and functionally distinct subset of serotonergic neurons via activation of CRF2 receptors.
We used the mouse pilocarpine model of temporal lobe epilepsy (TLE), and injected iontophoretically the anterograde tracer phaseolus vulgaris leucoagglutinin (PHA-L) into gliotic CA3, medial septum and the nucleus of diagonal band of Broca, median raphe, and lateral supramammillary nuclei, or the retrograde tracer cholera toxin B subunit (CTB) into gliotic CA3 area of hippocampus. In the afferent pathway, the number of neurons projecting to CA3 from medial septum and the nucleus of diagonal band of Broca, median raphe, and lateral supramammillary nuclei increased significantly.
The present investigation used single and multiple label tract tracing and immunofluorescence methods to evaluate the relative locations of the neuron groups and to compare them with the distributions of the three major afferent projections, the retinohypothalamic tract, geniculohypothalamic tract and the serotonergic pathway from the median raphe nucleus.
The IGL also provides a major input to the SCN, with a third major SCN afferent projection arriving from the median raphe nucleus.
Implantation of estrogen-filled cannulae into the median raphe, which projects to the hippocampus, resulted in a significant increase in spine density in the hippocampus after seven days of treatment.
The median raphe appears to be unaffected.
Other mesencephalic regions labelled from either site included the periaqueductal gray and dorsal and median raphe nuclei.
In this study, we examine the colocalization of vesicular glutamate transporter 3 immunoreactivity with serotonin immunoreactivity in the dorsal and median raphe nuclei of Syrian hamsters.
Measurement of 5-HT1A autoreceptors in the median raphe and 5-HT1B receptors in the SCN also showed no effect of LL.
The median raphe nucleus and dorsal raphe nucleus together are the major source of ascending 5-HT projections. Here, using in vitro extracellular single unit electrophysiology we examined the responses of individual neurones in the rat median raphe nucleus and dorsal raphe nucleus to alpha(1)-adrenoceptor and 5-HT(1A) receptor activation and made comparisons between the two nuclei. Compared to those in the dorsal raphe nucleus, the neurones in the median raphe nucleus which were inhibited by 5-HT had: (1) lower basal firing rates in the continuous presence of phenylephrine (1microM), (2) smaller excitatory responses to higher concentrations of phenylephrine (3-10microM), (3) smaller excitatory responses to brief application of norepinephrine (10-100microM) and (4) smaller inhibitory responses to 5-HT (10-50microM). The lower sensitivity of median raphe neurones to alpha(1)-adrenoceptor excitation and 5-HT(1A) receptor inhibition will have consequences for 5-HT neurotransmission in forebrain regions innervated by the two nuclei..
We detected strong hybridization signals in cell bodies located in the internal plexiform layer of the olfactory bulb, the interpeduncular nucleus of the midbrain, the ventral and dorsal tegmental nuclei, the median raphe nucleus of the pons, the ventral part of the medullary reticular nucleus, the ventral horn in the spinal cord of both rats and mice, and in a few Purkinje cells of rats, but not of mice.
The median raphe nucleus (MRN), which contains a major population of serotonin neurons, has also been implicated in freezing, but the serotonin neurons themselves do not seem to be involved, leaving it uncertain which neurons in this area promote freezing.
By contrast, infusion of muscimol in the median raphe increased locomotion and did not significantly alter the behavioral or EEG effects of halothane or pentobarbital. It is suggested that structures that activate the limbic cortices (MS, SUM, and VTA but not the median raphe) or mediate the output of the hippocampus (NAC and VP) normally participate in maintaining consciousness and inactivation of these structures potentiates the response to a general anesthetic..
TPH2 mRNA is confirmed as the raphe-specific isoform of TPH in human brain, and is expressed in neurons throughout the anteroposterior extent of the DRN and median raphe nucleus (MRN).
Testosterone infusion induced Fos above control in the posteromedial bed nucleus of the stria terminalis (BSTPM), posteromedial amygdala (MeP), lateral habenula (LHb), median raphe (MnR), lateral pontine nucleus (Pn), and ventral tegmental area (VTA).
Serotonergic projections to limbic structures, arising primarily from the dorsal and median raphe nuclei, compose two distinct serotonergic systems differing in their topographic organization, electrophysiological characteristics, morphology, as well as sensitivity to neurotoxins and perhaps psychoactive or therapeutic agents.
Several studies have shown that the median raphe nucleus (MRN) is involved in anxiety.
dorsal and median raphe nuclei), 5-HT1A receptor-stimulated [ 35S]GTPgammaS binding was not altered by chronic administration of amitriptyline, sertraline or venlafaxine.
Tryptophan hydroxylase immunoreactivity was increased in the median raphe nucleus at 2-3 weeks.
Studies revealed that FEV mRNA is robustly and exclusively expressed in the major serotonin-containing cell groups of the dorsal and median raphe nuclei located in the midbrain and pons of the human brainstem.
We have previously shown that brain serotonin depletion by lesions of the median raphe nucleus (MRN) causes enhancement of phencyclidine-induced locomotor hyperactivity [ S. van den Buuse, Differential role of serotonergic projections arising from the dorsal and median raphe nuclei in locomotor hyperactivity and prepulse inhibition, Neuropsychopharmacology 28 (2003) 2138-2147].
Estrogen receptors have been identified in the median raphe nucleus (MRN).
The median raphe nucleus (MRN) is the primary source of serotonergic afferents to the limbic system that are generally considered to suppress hippocampal theta oscillations.
These projections were established early in development and likely originated from the dorsal raphe, median raphe, raphe pontis, raphe magnus, and reticularis pontis oralis.
GIR mRNA showed widespread distribution in forebrain limbic and thalamic structures, and a more restricted distribution in hindbrain areas such as the spinal trigeminal nucleus and the median raphe nucleus.
Serotonergic neurons in the mesencephalic median raphe nucleus (MnR) also give rise to a major SCN afferent projection.
In contrast, neither a phase shift nor estradiol altered the number of Fos-immunoreactive cells or the proportion of Fos-positive 5-HT cells in the median raphe nucleus.
METHODS: In situ hybridization was used to quantify levels of 5-HT transporter (5-HTT), 5-HT(1A), 5-HT(1B), and alpha(1b)-adrenergic receptor (alpha(1b) ADR) messenger ribonucleic acids (mRNAs) in the dorsal (DRN) and median raphe (MR) nuclei of male Fischer rats after either sedentary housing or 3 days, 3 weeks, or 6 weeks of wheel running.
Inhibition of the median raphe nucleus (MRN) by the local injection of 5-HT(1A) or GABA(A) receptor agonists produces strong activational effects on feeding, drinking and locomotor activity.
The following areas were studied: dorsal raphe nucleus (DRN); median raphe nucleus (MRN); thalamus; hypothalamus; amygdala, and hippocampus.
A single dose of CP-93,129 caused a significant increase in the synthesis in the median raphe nucleus (MR) without a significant influence on the dorsal raphe nucleus (DR).
median raphe cyst (MRC) is a benign lesion occurring predominantly in the ventral surface of the penises of young men and is an embryological developmental anomaly of the male genitalia.
In the dorsal and median raphe nuclei 5-HT2C receptor mRNA was not detected in serotonergic cells identified as those expressing serotonin (5-HT) transporter mRNA. Such 5-HT2C receptor-positive GABAergic neurons were mainly located in the intermediolateral and lateral portions of the dorsal raphe and lateral part of the median raphe.
RATIONALE: A wealth of evidence supports the involvement of the serotonergic neurons of the median raphe nucleus (MRN) in anxiety.
We have previously shown that lesions of the median raphe nucleus, but not the dorsal raphe nucleus, produced a marked enhancement of locomotor hyperactivity induced by phencyclidine and disruption of prepulse inhibition. The dorsal and ventral hippocampus receive serotonin projections predominantly from the median raphe nucleus and dorsal raphe nucleus, respectively. These results suggest that serotonin projections from the median raphe nucleus to the dorsal hippocampus play an important role in locomotor hyperactivity and prepulse inhibition in rats, animal models of aspects of schizophrenia.
Both the dorsal and median raphe nuclei of the midline brainstem region in rats were lesioned with the neurotoxin 5,7-dihydroxytryptamine.
RATIONALE: Intra-median raphe nucleus (MRN) administration of the 5-HT(1A) receptor agonist 8-OH-DPAT decreases lateral hypothalamic self-stimulation thresholds and is reported to have biphasic effects following systemic administration.
The main sources of input to nucleus reuniens were from the orbitomedial, insular, ectorhinal, perirhinal, and retrosplenial cortices; CA1/subiculum of hippocampus; claustrum, tania tecta, lateral septum, substantia innominata, and medial and lateral preoptic nuclei of the basal forebrain; medial nucleus of amygdala; paraventricular and lateral geniculate nuclei of the thalamus; zona incerta; anterior, ventromedial, lateral, posterior, supramammillary, and dorsal premammillary nuclei of the hypothalamus; and ventral tegmental area, periaqueductal gray, medial and posterior pretectal nuclei, superior colliculus, precommissural/commissural nuclei, nucleus of the posterior commissure, parabrachial nucleus, laterodorsal and pedunculopontine tegmental nuclei, nucleus incertus, and dorsal and median raphe nuclei of the brainstem.
We examined the effect of the stimulation of the dorsal and median raphe nuclei (DR and MnR, respectively) on the activity of PFC neurons.
The effects of the lowest dose of PCA suggest that the neurotoxin affects not only the dorsal raphe projection areas but also the fine axons which arise from the median raphe.
The cell bodies of 5-HT containing neurons that innervate the limbic forebrain are mainly found in the dorsal raphe nucleus and in the median raphe nucleus (MRN). To assess the role of the median raphe nucleus in anxiety, rats bearing either electrolytic or 5-HT-selective neurotoxic lesion of the MRN were tested in the elevated T-maze.
RESULTS: Prenatal alcohol exposure increased the concentration of active caspase-3 in the brainstem and caused reductions in brain weight by 20% and in the total number of 5-HT-immunostaining neurons in the dorsal and median raphe nuclei by 20% at E18 as compared with those of the pair-fed and chow controls. Continuous observation from prenatal to postnatal stages showed that the reduction of 5-HT-immunostaining neurons in the dorsal and median raphe nuclei persisted in the young adult stage.
Group II (n = 152) had no releases; however, retropectoral pocket dissection was extended medially to the arc of the median raphe, where the tendinous origins of the pectoralis major muscle are firmly anchored to the anterior aspect of the sternum. This indicates that subpectoral mobilization to the arc of the median raphe afforded a proportionally decreased intermammary space, better medial envelope fill, and less lateral implant displacement when compared with medial pectoral releases. Above the fifth rib and below the clavicular head, the secure, tendinous origin of the pectoralis major muscle arises from the central anterior aspect of the sternum forming an "arc of the median raphe." This anatomic feature allows pectoral muscle mobilization medially, negating the need for division.
The experiment results demonstrate that discharge frequency of median raphe nuclei related to sleep changes significantly and the discharge becomes slow, which shows that magnetic stimulation can inhibit electrical activity of 5-HT nerve cell and provide a new way to improve insomnia..
These results together with anterograde tracer injection and chemical lesion experiments in the dorsal and median raphe nuclei revealed that the neocortex contains at least two kinds of VGLUT3-laden axon terminals: one is serotonergic and derived from the raphe nuclei, and the other is GABAergic and intrinsic in the neocortex.
Non-photic cues are notably conveyed to the SCN by a direct 5-HT pathway arising from the mesencephalic median raphe nucleus (MRN).
It has previously been shown that the median raphe nucleus (MR) is one of the main sources of projections to the septum and hippocampus.
Serotonergic median raphe nucleus and noradrenergic locus ceruleus act as functional antagonists in theta regulation: the former structure restricts the theta rhythm generation, whereas the latter enhances this process.
The mGlu1 receptor is also present in variable degree in the dorsal lateral septal nucleus, amygdala, interpeduncular nucleus and median raphe nucleus.
Furthermore, in the guinea pig there is a divergence between dorsal and median raphe innervated brain regions.
Other VGLUT3-positive boutons immunopositive for serotonergic markers but negative for GAD probably originate from the median raphe nucleus and innervate select interneurons.
The median raphe nucleus is involved in controlling and maintaining hippocampal activity through its projection to inhibitory neurons in medial septum and hippocampus. It has been shown that anterogradely axonal-traced fibers originating in the median raphe nucleus project onto calbindin-containing neurons in hippocampus and parvalbumin-containing neurons in medial septum. However, in both dorsal and median raphe nucleus there is a large amount of non-serotonergic neurons which also are projecting neurons, indicating that a part of the raphe fibers projecting to hippocampus and septum may be non-serotonergic. Biotin dextran amine was used as the anterograde neuronal tracer and injected into either dorsal or median raphe nucleus. Surprisingly, we found a significant non-serotonergic projection from both dorsal and median raphe nuclei onto calbindin- and parvalbumin-containing interneurons in septum and hippocampus, with a preference in hippocampus for projecting onto calbindin-positive neurons.
The pre-frontal and cingulate cortex, median raphe nucleus, septum and hippocampus seem to be implicated in the elaboration and organization of these responses.
Since rats with electrolytic lesion in the area of the median raphe nucleus displayed high frequencies of HD in a previous study, the present investigation was undertaken to confirm this observation and to determine its anxiety-related origin.
The electrical stimulation of the dorsal and median raphe nuclei elicited 5-HT1A-mediated inhibitions and 5-HT2A-mediated excitations in identified pyramidal neurons recorded extracellularly in rat medial prefrontal cortex (mPFC).
A single IMO elicited a threefold rise in TPH mRNA in median raphe nucleus (MRN), but repeated (3x) IMOs were needed for similar response in dorsal raphe nucleus (DRN).
Dorsal and median raphe nucleus (DRN and MRN), hippocampus (Hipp), striatum (Strt) and frontal cortex (FCx) were studied by computer-assisted image analysis.
Depletion of 5-HT was achieved by injecting 5,7-dihydroxytryptamine (5,7-DHT) into the dorsal and median raphe nuclei.
Thus, the mesencephalon and rostral pons, neurons within the rostral raphe complex (caudal linear, dorsal raphe, and median raphe nuclei) project primarily to the forebrain. The median raphe and dorsal raphe nuclei provide parallel and overlapping projections to many forebrain structures with axon fibers exhibiting distinct structural and functional characteristics.
Here, the role of the median raphe (MR), a serotonergic subcortical structure, is studied.
The expression of Fos protein in 5-HT-containing neurons (5-HT/Fos co-localized neurons) could be observed in the ventrolateral subdivision of the midbrain periaqueductal grey, interpeduncular nucleus, paramedian raphe nucleus, all of the brainstem raphe nuclei, the alpha part of the gigantocellular reticular nucleus and the lateral paragigantocellular reticular nucleus. However, the number and proportion of the 5-HT/Fos co-localized neurons in the median raphe nucleus and nucleus raphe obscurus of the rat subjected to visceral noxious stimulation were statistically greater than those in rats subjected to somatic noxious stimulation. These results suggest that serotonergic neurons in median raphe nucleus and nucleus raphe obscurus have a tendency to higher neuronal activity after visceral noxious stimulation..
In earlier studies it has been shown that stimulation of the median raphe nucleus (MR) in awake rabbits decreases the expression and frequency of oscillatory theta activity in the septohippocampal system, and the functional blockade of this nucleus evokes the regular and high-frequency theta rhythm.
8-OH-DPAT was injected into either the dorsal or median raphe of male and female rats at doses of 0.1-0.4 nmol. Dorsal and median raphe injections of 8-OH-DPAT dose dependently reversed the anorectic effect of FLU in male rats.
To determine the role of sympathetic output and brain monoamines in the different energy balance of Lou/C rats, the monoamine contents and activity of rate-limiting enzymes in catecholamine and serotonin biosynthesis were assessed in brain structures involved in energy balance regulation, i.e., brainstem noradrenergic (A6, A5, A2) and serotonergic cell groups (dorsal raphe, and median raphe), and two hypothalamic nuclei (ventromedial nucleus and paraventricular nucleus). The noradrenergic activity in A2, A6 and ventromedial nucleus, and the serotonergic pattern in A6, dorsal raphe and median raphe were lower in Lou/C.
The stereological analysis showed a significant difference in the number of 5-HT neurons in the dorsal but not in the median raphe of sP-N rats, compared with sNP and Wistar rats. Analysis of the cell body cross-sectional area revealed no differences among the three lines of rats either in the dorsal or in the median raphe.
We used double-label in situ hybridization to examine the cellular localization of 5-ht(5B) receptor mRNA in relation to serotonin transporter mRNA in the rat dorsal raphe (DR) and central superior nucleus (CS, median raphe nucleus).
Focal deposition of Abeta in the retrosplenial cortex resulted in a loss of serotoninergic neurons in the dorsal and median raphe nuclei. A statistically significant reduction of 50.3%, together with a significant decrease of 53.94% in the density of serotoninergic neurons, was also observed in the median raphe nucleus as compared with control animals.
Using a rat relapse model, we have shown that infusion of a corticotropin-releasing factor (CRF) receptor antagonist into the median raphe nucleus (MRN) blocks footshock stress-induced reinstatement of alcohol seeking in rats.
Main projection sites of PL are: the agranular insular cortex, claustrum, nucleus accumbens, olfactory tubercle, the paraventricular, mediodorsal, and reuniens nuclei of thalamus, the capsular part of the central nucleus and the basolateral nucleus of amygdala, and the dorsal and median raphe nuclei of the brainstem.
The dorsal (DR) and median raphe (MR) nuclei contain 5-hydroxytryptamine (serotonin, 5-HT) cell bodies that give rise to the majority of the ascending 5-HT projections to the forebrain limbic areas that control emotional behavior.
The mean deviation (MD) was compared among the 3 areas within one hemifield and between each pair of corresponding areas across the median raphe.
Ascending 5-HT projections from the median raphe nucleus (MRN), probably to the hippocampus, are implicated in the acquisition of contextual fear (background stimuli), as assessed by freezing behavior.
Previously, we reported that electrical stimulation of the dorsal raphe nucleus (DRN) or median raphe nucleus (MRN) in hamsters evoked 5-HT release in the SCN.
However, glucose utilization remained altered in the nucleus accumbens, mediodorsal thalamus, basolateral amygdala, portions of the hippocampus and median raphe.
Pentobarbital-anesthetized (60 mg/kg, i.p.) male Sprague-Dawley rats were stereotaxically microinjected with 1 microl of a 5 microg/microl solution of the serotonergic neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) into either the dorsal or median raphe nucleus. In contrast, rats with median raphe lesions showed significant enhancement of phencyclidine-induced, but not amphetamine-induced locomotor hyperactivity and a marked disruption of prepulse inhibition.
These data led us to conclude that there is a system of ascending projections arising from the nucleus incertus to the median raphe, mammillary complex, hypothalamus, lateral habenula, nucleus reuniens, amygdala, entorhinal cortex, medial septum, and hippocampus.
Discrete injection of the tracer Cholera toxin, subunit B, (ChB) was centred in the rat SCN, and a few retrograde labelled neurones were distributed in the dorsal and median raphe nuclei (MnR) and in the rostral part of the raphe magnus (RMg), but no neurones were found in the raphe pallidus or raphe obscurus.
Posterior 5HT cells (median raphe nucleus) innervate hippocampus and cingulate gyrus and suppress memory and awareness of current and past adversity.
At E13, there are fewer 5-HT-im neurons in either dorsal or median raphe of ALC as compared with PF or Chow; furthermore, neurite outgrowth and migration of the 5-HT neurons are also compromised with alcohol exposure.
This study examined the effect of the 5-HT in this region by measuring the electrophysiological response of ventral mPFC neurones to electrical stimulation of the dorsal and median raphe nuclei (DRN and MRN), which are the source of the 5-HT input.
We estimated the density of vimentin-positive glia of the midline raphe glial structure (MRGS) at GD 20 and postnatal day (PND) 5 and of glial fibrillary acidic protein (GFAP)-positive astrocytes proximal to the dorsal and median raphe at PNDs 5 and 19. The results of this study provide evidence that in utero ethanol exposure is associated with a reduced density of GFAP-immunopositive astrocytes proximal to the dorsal and median raphe. Maternal ipsapirone treatment significantly increased astroglial density in the dorsal raphe at PNDs 5 and 19 and in the median raphe at PND 5, such that it either prevented (dorsal raphe, PNDs 5 and 19) or blunted (median raphe, PND 5) the effects of ethanol..
However, amitriptyline exerted selective decreases of 15% and 17% (P < 0.001) in serotonin synthesis rates in the dorsal and median raphe nuclei, respectively.
In BDNF (+/-) versus wild-type (WT) mice, 5-HT1A receptor-stimulated [ 35S]GTP gamma S binding was significantly attenuated in the median raphe nucleus.
In 39 of these patients, sclerotherapy was performed bilaterally in the same session whilst in 34, rather than making two incisions at the root of the two hemiscrotums, a single incision was made on the median raphe. When the incision is made on the median raphe, no scars remain.
We have shown that 5-HT mechanisms of the median raphe nucleus (MRN) are involved in contextual fear-conditioning processes as electrolytic or neurotoxic lesions with N-methyl-D-aspartate (NMDA) or injections of 8-hydroxy-2-(di-n-propilamino)-tetralin (8-OH-DPAT) into this structure inhibit freezing behavior in a contextual fear paradigm.
We also tested the involvement of the median raphe 5-HT(1A) receptors in peripheral LPS- and IL-1 beta-induced anorexia. Rats were injected intraperitoneally with either LPS (100 microg/kg) or IL-1 beta (2 microg/kg) at lights out, and 8-OH-DPAT (4 nmol) was administered directly into the median raphe nucleus at the onset of anorexia. median raphe injections of 8-OH-DPAT significantly attenuated both IL-1 beta- and LPS-induced anorexia (both P<.01).
The level of CRH-IR was increased by 30% in the locus coeruleus, 39% in the median raphe and 45% in the caudal dorsal raphe in the depressed suicide subjects compared to controls.
The effects of injecting testosterone propionate or estradiol benzoate to newborn rats on dopaminergic and serotoninergic activity in the frontal cortex, dorsal and median raphe nucleus were analyzed when animals reached adulthood. An increase in androgen or estrogen levels at birth caused a significant decrease in serotoninergic activity in the frontal cortex and in the dorsal raphe nucleus, without causing apparent changes in dopaminergic activity; serotinergic activity in the median raphe nucleus was not affected.
No significant changes were observed in the dorsal and median raphe nuclei or pineal body.
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