Postnatal changes in the respiratory response of the conscious rat to serotonin 2A/2C receptor activation are reflected in the developmental pattern of fos expression in the brainstem

• Published in: Brain research Vol. 942; no. 1; pp. 51 - 57
• Main Authors: Cayetanot, Florence, Gros, Françoise, Larnicol, Nicole
• Format: Journal Article
• Language: English
• Published: London Elsevier B.V 28-06-2002; Amsterdam Elsevier; New York, NY
• Subjects: 5-HT 2 receptor; Aging; Aging - metabolism; Animals; Animals, Newborn; Biochemistry; Biochemistry, Molecular Biology; Biological and medical sciences; Brain Stem; Brain Stem - cytology; Brain Stem - growth & development; Brain Stem - metabolism; Cell Count; Consciousness; Consciousness - drug effects; Consciousness - physiology; Female; Fos expression; Fundamental and applied biological sciences. Psychology; Immunohistochemistry; Indophenol; Indophenol - analogs & derivatives; Indophenol - pharmacology; Life Sciences; Male; Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration; Nerve Net; Nerve Net - drug effects; Nerve Net - metabolism; Neurons; Neurons - cytology; Neurons - drug effects; Neurons - metabolism; Postnatal development; Proto-Oncogene Proteins c-fos; Proto-Oncogene Proteins c-fos - drug effects; Proto-Oncogene Proteins c-fos - metabolism; Rat; Rats; Rats, Sprague-Dawley; Receptor, Serotonin, 5-HT2A; Receptor, Serotonin, 5-HT2C; Receptors, Serotonin; Receptors, Serotonin - drug effects; Receptors, Serotonin - metabolism; Respiration; Respiratory Center; Respiratory Center - cytology; Respiratory Center - growth & development; Respiratory Center - metabolism; Respiratory Physiological Phenomena - drug effects; Respiratory Physiology; Serotonin; Serotonin - metabolism; Serotonin Agonists; Serotonin Receptor Agonists - pharmacology; Synaptic Transmission; Synaptic Transmission - drug effects; Synaptic Transmission - physiology; Up-Regulation; Up-Regulation - drug effects; Up-Regulation - physiology; Vertebrates: nervous system and sense organs; Serotonin; Rat; Endocrine and autonomic regulation; Fos expression; Respiration; Postnatal development; 5-HT 2 receptor; Brain stem; Rodentia; Central nervous system; Gene expression; 5-HT2 Serotonine receptor; Vertebrata; Mammalia; Respiratory control; Brain (vertebrata); Immediate early gene
• ISSN: 0006-8993; 1872-6240; 0006-8993
• DOI: 10.1016/S0006-8993(02)02690-2

The influence on the breathing pattern of the activation of serotonin receptors belonging to the subtypes 2
A and 2
C (5-HT
2A/2C) has been assessed in newborn and adult conscious rats. Rats were given an acute intraperitoneal dose of the agonist DOI (1-(2.5-dimethoxy-4-iodophenyl)-2-aminopropane; 5 mg/kg). In newborns, DOI elicited a long-lasting respiratory depression by decreasing both tidal volume and respiratory frequency. In adults, DOI retained a depressant influence, although attenuated, on tidal volume. In contrast, it elicited an increase in respiratory frequency. In separate subsets of newborn and adult rats, immunohistochemistry has been used to monitor c-fos expression induced by DOI in the medullary and pontine regions involved in respiratory control. Counts of immunoreactive neurons indicated a marked increase in the neuronal populations activated in the adult compared to the newborn rat. The response to both experimental factors (newborn vs. adult controls) and drug (injected vs. control age-matched rats) were more pronounced in mature animals. Among developmental changes in the pattern of labeling, DOI elicited Fos expression in the adult but not in the neonate in the ventrolateral subnucleus of the nucleus of the solitary tract, the parabrachial area and the Kölliker-Fuse nucleus. This finding suggested that changes in the respiratory response to DOI might at least partly depend on maturational events within networks involved in the modulation of respiratory timing.