TY - JOUR
T1 - Neural responses to intravenous serotonin revealed by functional magnetic resonance imaging
AU - Henderson, Luke A.
AU - Yu, Pearl L.
AU - Frysinger, Robert C.
AU - Galons, Jean Philippe
AU - Bandlerand, Richard
AU - Harper, Ronald M.
PY - 2002
Y1 - 2002
N2 - We examined the sequence of neural responses to the hypotension, bradycardia, and apnea evoked by intravenous administration of 5-hydroxytryptamine (serotonin). Functional magnetic resonance imaging signal changes were assessed in nine isoflurane-anesthetized cats during baseline and after a bolus intravenous low dose (10 μg/kg) or high dose (20-30 μg/kg) of 5-hydroxytryptamine. In all cats, high-dose challenges elicited rapid-onset, transient signal declines in the intermediate portion of the solitary tract nucleus, caudal midline and caudal and rostral ventrolateral medulla, and fastigial nucleus of the cerebellum. Slightly delayed phasic declines appeared in the dentate and interpositus nuclei and dorsolateral pons. Late-developing responses also emerged in the solitary tract nucleus, parapyramidal region, periaqueductal gray, spinal trigeminal nucleus, inferior olivary nucleus, cerebellar vermis, and fastigial nucleus. Amygdala and hypothalamic sites showed delayed and prolonged signal increases. Intravenous serotonin infusion recruits cerebellar, amygdala, and hypothalamic sites in addition to classic brain stem cardiopulmonary areas and exhibits site-specific temporal patterns.
AB - We examined the sequence of neural responses to the hypotension, bradycardia, and apnea evoked by intravenous administration of 5-hydroxytryptamine (serotonin). Functional magnetic resonance imaging signal changes were assessed in nine isoflurane-anesthetized cats during baseline and after a bolus intravenous low dose (10 μg/kg) or high dose (20-30 μg/kg) of 5-hydroxytryptamine. In all cats, high-dose challenges elicited rapid-onset, transient signal declines in the intermediate portion of the solitary tract nucleus, caudal midline and caudal and rostral ventrolateral medulla, and fastigial nucleus of the cerebellum. Slightly delayed phasic declines appeared in the dentate and interpositus nuclei and dorsolateral pons. Late-developing responses also emerged in the solitary tract nucleus, parapyramidal region, periaqueductal gray, spinal trigeminal nucleus, inferior olivary nucleus, cerebellar vermis, and fastigial nucleus. Amygdala and hypothalamic sites showed delayed and prolonged signal increases. Intravenous serotonin infusion recruits cerebellar, amygdala, and hypothalamic sites in addition to classic brain stem cardiopulmonary areas and exhibits site-specific temporal patterns.
KW - Apnea
KW - Bezold-Jarisch reflex
KW - Bradycardia
KW - Hypotension
KW - Myocardial ischemia
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U2 - 10.1152/jappl.2002.92.1.331
DO - 10.1152/jappl.2002.92.1.331
M3 - Article
C2 - 11744676
AN - SCOPUS:0036092945
VL - 92
SP - 331
EP - 342
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 1
ER -