5-HT2A receptors are expressed by catecholaminergic neurons in the rat nucleus tractus solitarii

• Published in: Neuroreport Vol. 13; no. 17; pp. 2365 - 2369
• Main Authors: Nosjean, Anne, Hamon, Michel, Darmon, Michèle
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott Williams & Wilkins, Inc 03-12-2002; Lippincott Williams and Wilkins; Lippincott, Williams & Wilkins
• Subjects: Animals; Axons; Axons - metabolism; Axons - ultrastructure; Biological and medical sciences; Catecholamines; Catecholamines - metabolism; Central nervous system; Central neurotransmission. Neuromudulation. Pathways and receptors; Cognitive Sciences; Dendrites; Dendrites - metabolism; Dendrites - ultrastructure; Dopamine beta-Hydroxylase; Dopamine beta-Hydroxylase - metabolism; Fluorescent Antibody Technique; Fundamental and applied biological sciences. Psychology; Life Sciences; Male; Neurobiology; Neurons; Neurons - cytology; Neurons - metabolism; Neurons and Cognition; Phenylethanolamine N-Methyltransferase; Phenylethanolamine N-Methyltransferase - metabolism; Psychology and behavior; Rats; Rats, Sprague-Dawley; Receptor, Serotonin, 5-HT2A; Receptors, Serotonin; Receptors, Serotonin - metabolism; Serotonin; Serotonin - metabolism; Solitary Nucleus; Solitary Nucleus - cytology; Solitary Nucleus - metabolism; Synaptic Transmission; Synaptic Transmission - physiology; Tyrosine 3-Monooxygenase; Tyrosine 3-Monooxygenase - metabolism; Vertebrates: nervous system and sense organs; Solitary nucleus; 5-HT2A serotonin receptor; Vertebrata; Mammalia; Catecholaminergic neuron; Rat; Rodentia; Central nervous system; Gene expression; Brain (vertebrata)
• ISSN: 0959-4965; 1473-558X
• DOI: 10.1097/00001756-200212030-00039

Within the nucleus tractus solitarii (NTS), serotonin (5-HT) exerts modulatory effects on central mechanisms controlling autonomic functions, notably through the stimulation of 5-HT2 receptors. Using double immunocytochemical labeling with specific anti-5-HT2A receptor antibodies and antibodies directed against the catecholamine (CA) synthesizing enzymes, i.e. tyrosine hydroxylase, dopamine β-hydroxylase (DBH) and phenylethanolamine N-methyltransferase, we investigated whether 5-HT effects could be mediated by 5-HT2A receptors located on CA perikarya and/or processes within the NTS. A relatively high density of 5-HT2A immunoreactive processes was observed throughout the NTS. 5-HT2A neuronal perikarya were also found within the NTS except in its rostrolateral part. Double immunolabeling experiments revealed many 5-HT2A receptors on CA processes but only few 5-HT2A/TH and 5-HT2A/DBH perikarya. These data support the idea that, within the NTS, 5-HT2A-mediated control of autonomic functions involves CA neurons.