Back to Search
Start Over
Intermittent activation of peripheral chemoreceptors in awake rats induces Fos expression in rostral ventrolateral medulla-projecting neurons in the paraventricular nucleus of the hypothalamus.
- Source :
-
Neuroscience [Neuroscience] 2008 Nov 19; Vol. 157 (2), pp. 463-72. Date of Electronic Publication: 2008 Sep 11. - Publication Year :
- 2008
-
Abstract
- Despite the well-established sympathoexcitation evoked by chemoreflex activation, the specific sub-regions of the CNS underlying such sympathetic responses remain to be fully characterized. In the present study we examined the effects of intermittent chemoreflex activation in awake rats on Fos-immunoreactivity (Fos-ir) in various subnuclei of the paraventricular nucleus of the hypothalamus (PVN), as well as in identified neurosecretory preautonomic PVN neurons. In response to intermittent chemoreflex activation, a significant increase in the number of Fos-ir cells was found in autonomic-related PVN subnuclei, including the posterior parvocellular, ventromedial parvocellular and dorsal-cap, but not in the neurosecretory magnocellular-containing lateral magnocellular subnucleus. No changes in Fos-ir following chemoreflex activation were observed in the anterior PVN subnucleus. Experiments combining Fos immunohistochemistry and neuronal tract tracing techniques showed a significant increase in Fos-ir in rostral ventrolateral medulla (RVLM)-projecting (PVN-RVLM), but not in nucleus of solitarii tract (NTS)-projecting PVN neurons. In summary, our results support the involvement of the PVN in the central neuronal circuitry activated in response to chemoreflex activation, and indicate that PVN-RVLM neurons constitute a neuronal substrate contributing to the sympathoexcitatory component of the chemoreflex.
- Subjects :
- Afferent Pathways drug effects
Afferent Pathways physiology
Analysis of Variance
Animals
Blood Pressure drug effects
Blood Pressure physiology
Heart Rate drug effects
Heart Rate physiology
Male
Medulla Oblongata drug effects
Neurons drug effects
Paraventricular Hypothalamic Nucleus drug effects
Potassium Cyanide pharmacology
Rats
Rats, Wistar
Medulla Oblongata physiology
Neurons metabolism
Oncogene Proteins v-fos metabolism
Paraventricular Hypothalamic Nucleus cytology
Wakefulness
Subjects
Details
- Language :
- English
- ISSN :
- 0306-4522
- Volume :
- 157
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Neuroscience
- Publication Type :
- Academic Journal
- Accession number :
- 18838112
- Full Text :
- https://doi.org/10.1016/j.neuroscience.2008.08.070