Author:
Penatti E. M.,Berniker A. V.,Kereshi B.,Cafaro C.,Kelly M. L.,Niblock M. M.,Gao H. G.,Kinney H. C.,Li A.,Nattie E. E.
Abstract
Acute inhibition of serotonergic (5-HT) neurons in the medullary raphé (MR) using a 5-HT1A receptor agonist had an age-dependent impact on the “CO2 response” of piglets ( 33 ). Our present study explored the effect of chronic 5-HT neuron lesions in the MR and extra-raphé on the ventilatory response to hypercapnia and hypoxia in piglets, with possible implications on the role of 5-HT in the sudden infant death syndrome. We established four experimental groups. Group 1 ( n = 11) did not undergo any treatment. Groups 2, 3, and 4 were injected with either vehicle or the neurotoxin 5,7-dihydroxytryptamine in the cisterna magna during the first week of life ( group 2, n = 9; group 4, n = 11) or second week of life ( group 3, n = 10). Ventilation was recorded in response to 5% CO2 (all groups) and 12% O2 ( group 2) during wakefulness and sleep up to postnatal day 25. Surprisingly, the piglets did not reveal changes in their CO2 sensitivity during early postnatal development. Overall, considerable lesions of 5-HT neurons (up to 65% decrease) in the MR and extra-raphé had no impact on the CO2 response, regardless of injection time. Postlesion raphé plasticity could explain why we observed no effect. 5,7-Dihydroxytryptamine-treated males, however, did present a lower CO2 response during sleep. Hypoxia significantly altered the frequency during sleep in lesioned piglets. Further studies are necessary to elucidate the role of plasticity, sex, and 5-HT abnormalities in sudden infant death syndrome.
Publisher
American Physiological Society
Subject
Physiology (medical),Physiology
Reference59 articles.
1. Control of breathing in experimental anemia
2. Baumgarten HG, Bjorklund A, Lackenmayer L, and Nobin A. Evaluation of the effects of 5,7-DHT on serotonin and catecholamine neurons in the rat CNS. Acta Physiol Scand Suppl 391: 1–19, 1973.
3. Age and gender effects on serotonin-dependent plasticity in respiratory motor control
4. Brown DR and Michels KM. Design and analysis of single-factor experiments: completely randomized design. In: Statistical Principles in Experimental Design (3rd ed), edited by Winer BJ, Brown DR, and Michels KM. New York: McGraw Hill, 1991, p. 146. [McGraw-Hill Series in Psychology]
5. Are there serotonergic projections from raphe and retrotrapezoid nuclei to the ventral respiratory group in the rat?
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