title: Vagal afferent activation decreases brown adipose tissue (BAT) sympathetic nerve activity and BAT thermogenesis.
abstract: In urethane/α-chloralose anesthetized rats, electrical stimulation of cervical vagal afferent fibers inhibited the increases in brown adipose tissue sympathetic nerve activity and brown adipose tissue thermogenesis evoked by cold exposure, by nanoinjection of the GABAAreceptor antagonist, bicuculline, in the dorsomedial hypothalamus, and by nanoinjection of N-methyl-D-aspartate in the rostral raphe pallidus. Vagus nerve stimulation-evoked inhibition of brown adipose tissue sympathetic nerve activity was prevented by blockade of ionotropic glutamate receptors in the termination site of vagal afferents in the nucleus of the solitary tract, and by nanoinjection of GABAAreceptor antagonists in the rostral raphe pallidus. In conclusion, the brown adipose tissue sympathoinhibitory effect of cervical afferent vagal nerve stimulation is mediated by glutamatergic activation of second-order sensory neurons in the nucleus of the solitary tract and by a GABAergic inhibition of brown adipose tissue sympathetic premotor neurons in the rostral raphe pallidus, but does not require GABAergic inhibition of the brown adipose tissue sympathoexcitatory neurons in the dorsomedial hypothalamus.
authors.affiliation: Department of Neurological Surgery, Oregon Health & Science University , Portland, OR, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Madden
authors.affiliation: Department of Neurological Surgery, Oregon Health & Science University , Portland, OR, USA.
authors.forename: Ellen Paula
authors.initials: EP
authors.lastname: Santos da Conceicao
authors.affiliation: Department of Neurological Surgery, Oregon Health & Science University , Portland, OR, USA.
authors.forename: Shaun F
authors.initials: SF
authors.lastname: Morrison
keywords: NTS; VNS; raphe pallidus; thermoregulation; vagus