TY - JOUR
T1 - Lipopolysaccharide activates specific populations of hypothalamic and brainstem neurons that project to the spinal cord
AU - Zhang, Yi Hong
AU - Lu, Jun
AU - Elmquist, Joel K.
AU - Saper, Clifford B.
PY - 2000/9/1
Y1 - 2000/9/1
N2 - Sympathetic preganglionic neurons receive direct, monosynaptic input from a series of well defined nuclei in the brainstem and the hypothalamus. These premotor cell groups coordinate sympathetic control with ongoing endocrine and behavioral response. However, it is not known precisely which populations of sympathetic premotor neurons are activated during specific responses, such as fever after intravenous lipopolysaccharide (LPS). We used the activation of c-fos protein expression in spinally projecting neurons during intravenous LPS fever as a model for examining the functional organization of this system. Intravenous LPS (5 μg/kg) induced Fos-like immunoreactivity in sympathetic preganglionic neutrons in the spinal cord as well as several sympathetic premotor nuclei, including the paraventricular nucleus of the hypothalamus, rostral and caudal levels of the ventrolateral medulla, and the nucleus of the solitary tract. After injecting Fluorogold into the intermediolateral column at the T1-L1 spinal levels, neurons that were both Fos immunoreactive and retrogradely labeled were found only in the dorsal parvicellular division of the paraventricular nucleus in the hypothalamus, the rostral ventrolateral medulla (C1 adrenergic cell group), and the A5 noradrenergic cell group in the brainstem. The same pattern of double-labeling was seen from injections at each spinal cord level. These findings suggest that only a limited pool of hypothalamo-sympathetic neurons contribute to the fever response and that they may do so by contacting specific populations of preganglionic neurons that are distributed across a wide range of spinal levels. The anatomical specificity of the paraventriculospinal projection is thus functional rather than topographic.
AB - Sympathetic preganglionic neurons receive direct, monosynaptic input from a series of well defined nuclei in the brainstem and the hypothalamus. These premotor cell groups coordinate sympathetic control with ongoing endocrine and behavioral response. However, it is not known precisely which populations of sympathetic premotor neurons are activated during specific responses, such as fever after intravenous lipopolysaccharide (LPS). We used the activation of c-fos protein expression in spinally projecting neurons during intravenous LPS fever as a model for examining the functional organization of this system. Intravenous LPS (5 μg/kg) induced Fos-like immunoreactivity in sympathetic preganglionic neutrons in the spinal cord as well as several sympathetic premotor nuclei, including the paraventricular nucleus of the hypothalamus, rostral and caudal levels of the ventrolateral medulla, and the nucleus of the solitary tract. After injecting Fluorogold into the intermediolateral column at the T1-L1 spinal levels, neurons that were both Fos immunoreactive and retrogradely labeled were found only in the dorsal parvicellular division of the paraventricular nucleus in the hypothalamus, the rostral ventrolateral medulla (C1 adrenergic cell group), and the A5 noradrenergic cell group in the brainstem. The same pattern of double-labeling was seen from injections at each spinal cord level. These findings suggest that only a limited pool of hypothalamo-sympathetic neurons contribute to the fever response and that they may do so by contacting specific populations of preganglionic neurons that are distributed across a wide range of spinal levels. The anatomical specificity of the paraventriculospinal projection is thus functional rather than topographic.
KW - A5 cell group
KW - Fever
KW - Intermediolateral cell column
KW - Lipopolysaccharide
KW - Paraventricular nucleus of the hypothalamus
KW - Rostral ventrolateral medulla
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U2 - 10.1523/jneurosci.20-17-06578.2000
DO - 10.1523/jneurosci.20-17-06578.2000
M3 - Article
C2 - 10964963
AN - SCOPUS:0034279194
SN - 0270-6474
VL - 20
SP - 6578
EP - 6586
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 17
ER -