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Brainstem areas activated by intermittent apnea in awake unrestrained rats
Author(s) -
Schoorlemmer Guus H.,
Falquetto Barbara,
Ferreira Caroline B.,
Takakura Ana C.,
Moreira Thiago S.,
Cravo Sergio L.
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.899.6
Subject(s) - medicine , brainstem , anesthesia , apnea , pons , medulla , balloon catheter , rostral ventrolateral medulla , anatomy , endocrinology , medulla oblongata , central nervous system , balloon
Patients with obstructive sleep apnoea experience repeated hypoxia, hypercapnia, and changes in pulmonary afferent traffic, resulting in autonomic activation and hypertension. We analyzed brain areas activated by apnea in conscious rats by c‐fos immunohistochemistry. Wistar rats (n= 9, 300–380 g) were anaesthetized with ketamine + xylazine, and balloon‐tipped catheters were implanted in the trachea. The balloon tip was contained in a rigid thin‐walled Teflon tube, 6 mm long, 2.2 mm diameter. Inflation of the balloon closed the lumen of the Teflon tube, and induced obstructive apnea without inducing pain in the trachea. The free end of the catheter was exteriorized on the rat's back. One week after surgery, five rats were subjected to intermittent apnea (14 s each 2 min) for 1 h, and sacrificed 30 min after the end of apneas for analysis of c‐fos. The four remaining rats were used as controls. Apnea increased the number of c‐fos immunoreactive cells in the parabrachial and Kölliker‐Fuse complex, retrotrapezoid nucleus, commissural and dorsomedial nucleus of the solitary tract and both the rostral (RVLM) and caudal ventrolateral medulla (CVLM). Tyrosine hydroxylase was present in many of the c‐fos positive neurons in the C1 region (69 ± 3%), but not in the A1 or A2 catecholaminergic regions. In conclusion, apnea activates specific brainstem areas involved in autonomic control. Financial support: FAPESP