Age-related changes in serotonin in the hypoglossal nucleus of rat: implications for sleep-disordered breathing.
We are attempting to determine the neuronal factors that influence upper airway patency during sleep in the elderly. Serotonin has a facilitatory effect on hypoglossal motoneurons that innervate the tongue, and manipulations of the serotonergic system alter airway patency. We hypothesized that age-associated changes in serotonergic input to the hypoglossal nucleus might be a factor in the increased susceptibility to sleep-disordered breathing in the elderly. We used light microscopic immunocytochemistry to study the distribution of serotonin in the hypoglossal nucleus in young and old rats. Rats > 18 months had fewer serotonin immunoreactive axons and boutons in the hypoglossal nucleus than rats < 6 months. These data suggest that normal aging may result in a change in the availability of serotonin that results in decreased facilitation of hypoglossal motoneurons.
Behan
M
M
Department of Comparative Biosciences, University of Wisconsin, Madison 53706, USA. behanm@svm.vetmed.wisc.edu
Brownfield
M S
MS
D000375:Aging / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D001369:Axons / Q000378:metabolism / Q000502:physiology; D007002:Hypoglossal Nerve / Q000378:metabolism* / Q000502:physiology; D007150:Immunohistochemistry; D051381:Rats; D011916:Rats, Inbred F344; D012701:Serotonin / Q000378:metabolism*; D012891:Sleep Apnea Syndromes / Q000378:metabolism* / Q000503:physiopathology*
D012701:Serotonin