1. Increased sympathetic nerve discharge without alteration in the sympathetic baroreflex response by serotonin3 receptor stimulation in the nucleus tractus solitarius of the rat
- Author
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Anne Nosjean, Bernard Franc, Raul Laguzzi, Neuropsychopharmacologie moléculaire, cellulaire et fonctionnelle, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM), and PERIGNON, Alain
- Subjects
Male ,Sympathetic nervous system ,Sympathetic Nervous System ,Baroreceptor ,[SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology ,[SDV.NEU.PC] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Psychology and behavior ,Blood Pressure ,MESH: Rats, Sprague-Dawley ,MESH: Microinjections ,MESH: Serotonin Antagonists ,Rats, Sprague-Dawley ,MESH: Pressoreceptors ,Zacopride ,chemistry.chemical_compound ,0302 clinical medicine ,MESH: Animals ,MESH: Sympathetic Nervous System ,0303 health sciences ,MESH: Solitary Nucleus ,[SDV.NEU.PC]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Psychology and behavior ,General Neuroscience ,[SDV.NEU.SC]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Cognitive Sciences ,MESH: Blood Pressure ,MESH: Serotonin Receptor Agonists ,Serotonin Receptor Agonists ,medicine.anatomical_structure ,Serotonin Antagonists ,circulatory and respiratory physiology ,Agonist ,Serotonin ,MESH: Receptors, Serotonin ,medicine.medical_specialty ,Microinjections ,MESH: Rats ,medicine.drug_class ,Pressoreceptors ,Baroreflex ,03 medical and health sciences ,Internal medicine ,Solitary Nucleus ,medicine ,Animals ,Microinjection ,030304 developmental biology ,Solitary nucleus ,[SDV.NEU.NB] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology ,MESH: Male ,Rats ,Endocrinology ,nervous system ,chemistry ,Receptors, Serotonin ,MESH: Serotonin ,Neuroscience ,[SDV.NEU.SC] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Cognitive Sciences ,030217 neurology & neurosurgery - Abstract
International audience; Previous studies have shown that serotonin3 receptor activation in the nucleus tractus solitarius (NTS) increased mean arterial pressure (MAP) and inhibited the cardiac component of the baroreceptor reflex [9]. We have examined the effects of such stimulation upon spontaneous and evoked sympathetic nerve activity. Microinjection of serotonin (10 nmol) into the NTS of halothane-anaesthetized, paralyzed and artificially ventilated rats produced an increase in MAP and lumbar sympathetic nerve discharge which could be completely prevented by prior local microinjection of zacopride, a potent serotonin3 antagonist (200 pmol). In addition, 1-(m-chlorophenyl)-biguanide, a selective serotonin3 receptor agonist, mimicked the sympathoexcitatory effect of serotonin. Since the gain of the sympathetic component of the baroreflex was unaltered after intra-NTS microinjection of serotonin, it could be concluded that serotonin3 receptors activation in the NTS induces a sympathetic activation which is not mediated through an inhibition of the sympathetic baroreceptor reflex arc.
- Published
- 1995