5-Hydroxytryptamine3 receptor modulation of excitatory amino acid release in the rat nucleus tractus solitarius

Ashworth-Preece, Mark A; Jarrott, Bevyn; Lawrence, Andrew J

doi:10.1016/0304-3940(95)11564-5

Cited by 43 publications

(23 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, we found that the inhibitory effect of dPAG electrical or chemical stimulation on PECR could be blocked not only by intra-NTS microinjections of a 5-HT 3 receptor antagonist, granisetron, but also by local microinjections of a GABA A receptor antagonist, bicuculline. Taking into account these and previous data, it can be hypothetized that the inhibition by dPAG stimulation of the cardiovagal component of the baroreceptor reflex implies the following sequence: 1) excitation (by electrical or chemical stimulation) of dPAG cell bodies triggers the release of endogenous 5-HT within the NTS and consequently the activation of local presynaptic 5-HT 3 receptors (21, 23); 2) stimulation of these receptors on vagal afferent fibers promotes the local release of glutamate (1), which, in turn, activates GABAergic interneurons; and 3) the resulting stimulation of GABA A receptors finally exerts an inhibitory influence on NTS neurons at the origin of the aortic and carotid cardiac responses of the baroreceptor reflex.…”

Section: Discussionmentioning

confidence: 81%

5-HT-mediated inhibition of cardiovagal baroreceptor reflex response during defense reaction in the rat

Comet¹,

Sévoz‐Couche²,

Hanoun³

et al. 2004

American Journal of Physiology-Heart and Circulatory Physiology

View full text Add to dashboard Cite

Comet, Marie-Anne, Caroline Sévoz-Couche, Naïma Hanoun, Michel Hamon, and Raul Laguzzi. 5-HT-mediated inhibition of cardiovagal baroreceptor reflex response during defense reaction in the rat. Am J Physiol Heart Circ Physiol 287: H1641-H1649, 2004. First published May 27, 2004 10.1152 10. /ajpheart.01204.2003ous studies showed that the cardiac response of the baroreceptor reflex (bradycardia) is inhibited during the defense reaction evoked by direct electrical or chemical stimulation of the periaqueductal gray (dPAG) in the rat. Whether central serotonin and nucleus tractus solitarius (NTS) serotonin 3 (5-HT3) receptors might participate in this inhibition was investigated in urethane-anesthetized and atenolol-pretreated rats. Our results showed that both electrical and chemical stimulation of the dPAG produced a drastic reduction of the cardiovagal component of the baroreceptor reflex triggered by either intravenous administration of phenylephrine or aortic nerve stimulation. This inhibitory effect of dPAG stimulation on the baroreflex bradycardia was not observed in rats that had been pretreated with p-chlorophenylalanine (300 mg/kg ip daily for 3 days) to inhibit serotonin synthesis. Subsequent 5-hydroxytryptophan administration (60 mg/kg ip), which was used to restore serotonin synthesis, allowed the inhibitory effect of dPAG stimulation on both aortic and phenylephrine-induced cardiac reflex responses to be recovered in p-chlorophenylalanine-pretreated rats. On the other hand, in nonpretreated rats, the inhibitory effect of dPAG stimulation on the cardiac baroreflex response could be markedly reduced by prior intra-NTS microinjection of granisetron, a 5-HT 3 receptor antagonist, or bicuculline, a GABAA receptor antagonist. These results show that serotonin plays a key role in the dPAG stimulation-induced inhibition of the cardiovagal baroreceptor reflex response. Moreover, they support the idea that 5-HT 3 and GABAA receptors in the NTS contribute downstream to the inhibition of the baroreflex response caused by dPAG stimulation. nucleus tractus solitarius; serotonin3 receptors; GABAA receptors; defense/attack MUCH EVIDENCE indicates that serotonin (5-hydroxytryptamine; 5-HT) plays a modulatory role in the central control of cardiovascular parameters (28, 32), notably through actions at the level of the nucleus tractus solitarius (NTS) (13, 15), a key structure for the integration of baroreceptor and other peripheral and central messages involved in the homeostatic control of blood pressure (BP) and heart rate (HR) (9,11,19). In particular, serotonin 3 (5-HT 3 ) receptor stimulation specifically in the NTS was shown to elicit a transitory increase in BP and to block the cardiovagal component (bradycardia) of the baroreceptor reflex (15,25). Interestingly, transient hypertension and inhibition of the cardiac baroreceptor reflex response are also the cardiovascular changes that accompany the defense reaction and other behavioral responses to various stressful conditions (16,17).Inhibition of the baroreceptor...

show abstract

Section: Discussionmentioning

confidence: 81%

5-HT-mediated inhibition of cardiovagal baroreceptor reflex response during defense reaction in the rat

Comet¹,

Sévoz‐Couche²,

Hanoun³

et al. 2004

American Journal of Physiology-Heart and Circulatory Physiology

View full text Add to dashboard Cite

show abstract

“…Similarly, presynaptic inhibition of GABA release is mediated by 5-HT 1A [90,95,96] and 5-HT 1B receptors [88,117]. By activation of 5-HT 3 receptors, instead, 5-HT stimulates the release of either glutamate [7,57,185] or GABA [90,96,179]. Also 5-HT 2 receptors were shown to stimulate GABA release [2] and to either increase [2,72,177] or reduce [118] glutamate release in distinct structures.…”

Section: Modes Of Interactionmentioning

confidence: 99%

“…For example, in tractus solitarius nucleus [7], dorsal vagal motor nucleus [185] and area postrema [57] 5-HT stimulates glutamate release by activation of pre-synaptic 5-HT 3 receptors. In suprachiasmatic nucleus, pre-synaptic 5-HT 1B receptors inhibit retinal input [151] whereas 5-HT 7 receptors reduce glutamate effects at a post-synaptic level [155]; by these effects, serotonin changes neuronal responsiveness to light stimuli and participates to the regulation of circadian rhythms.…”

Section: Modulation Of Glutamate Transmissionmentioning

confidence: 99%

“…In particular, subtypes *Address correspondence to this author at Dipartimento di Scienze Fisiologiche, Università di Catania, 6, Viale Andrea Doria, 95125 Catania, Italy; E-mail: ciranna@unict.it belonging to the 5-HT 1 family are coupled to a G-protein of the G i/o type and reduce adenylate cyclase activity; 5-HT 2 receptor subtypes activate phospholypase C, thus stimulating PI hydrolysis and intracellular Ca 2+ release; 5-HT 4, 5-HT 6 and 5-HT 7 are instead positively coupled to adenylate cyclase (through a G s ) and increase cAMP levels. The final effect on membrane potential is hyperpolarizing for 5-HT 1A receptors and depolarizing for most other subtypes, with a fast depolarization mediated by 5-HT 3 receptors and a slow depolarization mediated by 5-HT 2A-B , 5-HT 4 and 5-HT 7 receptors. 5-HT 2C were shown to exert either hyperpolarizing [25,37] or depolarizing effects [48,190] in distinct areas.…”

Section: Introductionmentioning

confidence: 99%

“…Serotonin Receptor Subtypes. 5-HT receptors have been grouped into seven principal classes, named 5-HT 1 to 5-HT 7 ; for each subtype, the table indicates the pharmacological characteristics, the localization, the intracellular action mechanism and final effect on neuronal excitability, the physiological function in which the receptor is involved and the pathologies deriving from its malfunctioning. Abbreviations: Ih hyperpolarization-activated nonselective cation current; gNa sodium conductance; gK potassium conductance.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Serotonin as a Modulator of Glutamate- and GABA-Mediated Neurotransmission: Implications in Physiological Functions and in Pathology

Ciranna

2006

272

170

View full text Add to dashboard Cite

Abstract:The neurotransmitter serotonin (5-HT), widely distributed in the central nervous system (CNS), is involved in a large variety of physiological functions. In several brain regions 5-HT is diffusely released by volume transmission and behaves as a neuromodulator rather than as a "classical" neurotransmitter. In some cases 5-HT is co-localized in the same nerve terminal with other neurotransmitters and reciprocal interactions take place. This review will focus on the modulatory action of 5-HT on the effects of glutamate and -amino-butyric acid (GABA), which are the principal neurotransmitters mediating respectively excitatory and inhibitory signals in the CNS. Examples of interaction at preand/or post-synaptic levels will be illustrated, as well as the receptors involved and their mechanisms of action. Finally, the physiological meaning of neuromodulatory effects of 5-HT will be briefly discussed with respect to pathologies deriving from malfunctioning of serotonin system.

show abstract

The role of central 5-HT2C and NMDA receptors on LPS-induced feeding behavior in chickens

et al. 2012

View full text Add to dashboard Cite

In mammals, LPS regulate feeding primarily through the 5-HT(1A) and 5-HT(2c) receptors within the brain. However, the central effect of 5-HT(1A) and 5-HT(2c) on LPS-induced feeding behavior has not been studied in non-mammalian species. Also, the role of glutamatergic system in LPS-induced anorexia has never been examined in either mammalian or non-mammalian species. Therefore, in this study, we examined the role of serotonergic and glutamatergic systems on LPS-induced anorexia in chickens. Food intake was measured in chickens after centrally administered lipopolysaccharide (LPS) (20 ng) (0 h), followed by intracerebroventricular (ICV) injection of the 5-HT(1A) autoreceptor agonist (8-OH-DPAT, 61 nmol), 5-HT(2c) receptor antagonist (SB 242084, 30 nm), and NMDA receptor antagonist (DL-AP5, 5 nm) at the onset of anorexia (4 h). In the following experiments, we used DL-AP5 before 5-HT (10 μg) and SB242084 before glutamate (300 nm) for evaluation of the interaction between 5-HTergic and glutamatergic systems on food intake. The results of this study showed that SB 242084 and DL-AP5 significantly attenuated food intake reduction caused by LPS (P < 0.05) but 8-OH-DPAT had no effect. In addition, 5-HT-induced anorexia was significantly attenuated by DL-AP5 pretreatment (P < 0.05), while SB 242084 had no effect on glutamate-induced hypophagia. These results indicated that 5-HT and glutamate (via 5-HT(2c) and NMDA receptor, respectively) dependently regulate LPS-induced hypophagia in chickens.

show abstract

5-Hydroxytryptamine3 receptor modulation of excitatory amino acid release in the rat nucleus tractus solitarius

Cited by 43 publications

References 25 publications

5-HT-mediated inhibition of cardiovagal baroreceptor reflex response during defense reaction in the rat

5-HT-mediated inhibition of cardiovagal baroreceptor reflex response during defense reaction in the rat

Serotonin as a Modulator of Glutamate- and GABA-Mediated Neurotransmission: Implications in Physiological Functions and in Pathology

The role of central 5-HT2C and NMDA receptors on LPS-induced feeding behavior in chickens

Contact Info

Product

Resources

About