Ultrastructural localization and afferent sources of corticotropin- releasing factor in the rat rostral ventrolateral medulla: Implications for central cardiovascular regulation

T. A. Milner, D. J. Reis, V. M. Pickel, Sue Aicher, R. Giuliano

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

We investigated the ultrastructural localization, afferent sources, and arterial pressure effects of corticotropin-releasing factor (CRF) in the nucleus reticularis rostroventrolateralis (RVL), a region of the ventrolateral medulla containing C1 adrenergic neurons and sympathoexcitatory reticulospinal afferents to sympathetic preganglionic neurons. A polyclonal antibody to CRF was localized in acrolein-fixed sections through the rat RVL by the peroxidase-antiperoxidase (PAP) method. Light microscopy showed that 1-7 perikarya/30 μm section and numerous varicose processes contained CRF- like immunoreactivity (CRF-LI). By electron microscopy, CRF-LI was most intensely localized to large (80-100 nm) dense-core vesicles within numerous terminals and a few perikarya and large dendrites. Approximately half of the terminals containing CRF-LI were in direct contact with unlabeled perikarya or dendrites; the remainder were in apposition to either unlabeled terminals or astrocytes. Most synaptic specializations were asymmetric synapses on small, unlabeled dendrites. To examine potential extrinsic sources of CRF- containing terminals in the C1 area of the RVL, PAP immunocytochemical localization of CRF was combined with retrograde transport of wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP). In all cases examined, a number of dually labeled neurons were found in the paraventricular nucleus (PVN) of the hypothalamus and a few dually labeled neurons were observed in the nuclei of the solitary tract; these labeled neurons were ipsilateral to the unilateral injection of WGA-HRP into the C1 area. Fewer dually labeled perikarya were detected in the lateral hypothalamic area and the lateral parabrachial nuclei, ipsilateral to the WGA-HRP injection. Additional physiological studies showed that bilateral microinjections of CRF into the C1 area of the RVL of urethane-anesthetized rats elicited a dose-related increase in arterial pressure. The results suggest that within the C1 area of the RVL, CRF released from terminals, arising predominantly from the PVN of the hypothalamus and probably from local neurons as well, may excite sympathoexcitatory reticulospinal neurons.

Original languageEnglish (US)
Pages (from-to)151-167
Number of pages17
JournalJournal of Comparative Neurology
Volume333
Issue number2
StatePublished - 1993
Externally publishedYes

Fingerprint

Corticotropin-Releasing Hormone
Neurons
Wheat Germ Agglutinins
Horseradish Peroxidase
Dendrites
Paraventricular Hypothalamic Nucleus
Peroxidase
Hypothalamus
Arterial Pressure
Lateral Hypothalamic Area
Acrolein
Adrenergic Neurons
Injections
Solitary Nucleus
Urethane
Secretory Vesicles
Microinjections
Astrocytes
Synapses
Microscopy

Keywords

  • C1 area
  • electron microscopy
  • paraventricular nucleus of the hypothalamus

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Ultrastructural localization and afferent sources of corticotropin- releasing factor in the rat rostral ventrolateral medulla : Implications for central cardiovascular regulation. / Milner, T. A.; Reis, D. J.; Pickel, V. M.; Aicher, Sue; Giuliano, R.

In: Journal of Comparative Neurology, Vol. 333, No. 2, 1993, p. 151-167.

Research output: Contribution to journalArticle

@article{2b21fbc36ee846018156107ee383d3ec,
title = "Ultrastructural localization and afferent sources of corticotropin- releasing factor in the rat rostral ventrolateral medulla: Implications for central cardiovascular regulation",
abstract = "We investigated the ultrastructural localization, afferent sources, and arterial pressure effects of corticotropin-releasing factor (CRF) in the nucleus reticularis rostroventrolateralis (RVL), a region of the ventrolateral medulla containing C1 adrenergic neurons and sympathoexcitatory reticulospinal afferents to sympathetic preganglionic neurons. A polyclonal antibody to CRF was localized in acrolein-fixed sections through the rat RVL by the peroxidase-antiperoxidase (PAP) method. Light microscopy showed that 1-7 perikarya/30 μm section and numerous varicose processes contained CRF- like immunoreactivity (CRF-LI). By electron microscopy, CRF-LI was most intensely localized to large (80-100 nm) dense-core vesicles within numerous terminals and a few perikarya and large dendrites. Approximately half of the terminals containing CRF-LI were in direct contact with unlabeled perikarya or dendrites; the remainder were in apposition to either unlabeled terminals or astrocytes. Most synaptic specializations were asymmetric synapses on small, unlabeled dendrites. To examine potential extrinsic sources of CRF- containing terminals in the C1 area of the RVL, PAP immunocytochemical localization of CRF was combined with retrograde transport of wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP). In all cases examined, a number of dually labeled neurons were found in the paraventricular nucleus (PVN) of the hypothalamus and a few dually labeled neurons were observed in the nuclei of the solitary tract; these labeled neurons were ipsilateral to the unilateral injection of WGA-HRP into the C1 area. Fewer dually labeled perikarya were detected in the lateral hypothalamic area and the lateral parabrachial nuclei, ipsilateral to the WGA-HRP injection. Additional physiological studies showed that bilateral microinjections of CRF into the C1 area of the RVL of urethane-anesthetized rats elicited a dose-related increase in arterial pressure. The results suggest that within the C1 area of the RVL, CRF released from terminals, arising predominantly from the PVN of the hypothalamus and probably from local neurons as well, may excite sympathoexcitatory reticulospinal neurons.",
keywords = "C1 area, electron microscopy, paraventricular nucleus of the hypothalamus",
author = "Milner, {T. A.} and Reis, {D. J.} and Pickel, {V. M.} and Sue Aicher and R. Giuliano",
year = "1993",
language = "English (US)",
volume = "333",
pages = "151--167",
journal = "Journal of Comparative Neurology",
issn = "0021-9967",
publisher = "Wiley-Liss Inc.",
number = "2",

}

TY - JOUR

T1 - Ultrastructural localization and afferent sources of corticotropin- releasing factor in the rat rostral ventrolateral medulla

T2 - Implications for central cardiovascular regulation

AU - Milner, T. A.

AU - Reis, D. J.

AU - Pickel, V. M.

AU - Aicher, Sue

AU - Giuliano, R.

PY - 1993

Y1 - 1993

N2 - We investigated the ultrastructural localization, afferent sources, and arterial pressure effects of corticotropin-releasing factor (CRF) in the nucleus reticularis rostroventrolateralis (RVL), a region of the ventrolateral medulla containing C1 adrenergic neurons and sympathoexcitatory reticulospinal afferents to sympathetic preganglionic neurons. A polyclonal antibody to CRF was localized in acrolein-fixed sections through the rat RVL by the peroxidase-antiperoxidase (PAP) method. Light microscopy showed that 1-7 perikarya/30 μm section and numerous varicose processes contained CRF- like immunoreactivity (CRF-LI). By electron microscopy, CRF-LI was most intensely localized to large (80-100 nm) dense-core vesicles within numerous terminals and a few perikarya and large dendrites. Approximately half of the terminals containing CRF-LI were in direct contact with unlabeled perikarya or dendrites; the remainder were in apposition to either unlabeled terminals or astrocytes. Most synaptic specializations were asymmetric synapses on small, unlabeled dendrites. To examine potential extrinsic sources of CRF- containing terminals in the C1 area of the RVL, PAP immunocytochemical localization of CRF was combined with retrograde transport of wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP). In all cases examined, a number of dually labeled neurons were found in the paraventricular nucleus (PVN) of the hypothalamus and a few dually labeled neurons were observed in the nuclei of the solitary tract; these labeled neurons were ipsilateral to the unilateral injection of WGA-HRP into the C1 area. Fewer dually labeled perikarya were detected in the lateral hypothalamic area and the lateral parabrachial nuclei, ipsilateral to the WGA-HRP injection. Additional physiological studies showed that bilateral microinjections of CRF into the C1 area of the RVL of urethane-anesthetized rats elicited a dose-related increase in arterial pressure. The results suggest that within the C1 area of the RVL, CRF released from terminals, arising predominantly from the PVN of the hypothalamus and probably from local neurons as well, may excite sympathoexcitatory reticulospinal neurons.

AB - We investigated the ultrastructural localization, afferent sources, and arterial pressure effects of corticotropin-releasing factor (CRF) in the nucleus reticularis rostroventrolateralis (RVL), a region of the ventrolateral medulla containing C1 adrenergic neurons and sympathoexcitatory reticulospinal afferents to sympathetic preganglionic neurons. A polyclonal antibody to CRF was localized in acrolein-fixed sections through the rat RVL by the peroxidase-antiperoxidase (PAP) method. Light microscopy showed that 1-7 perikarya/30 μm section and numerous varicose processes contained CRF- like immunoreactivity (CRF-LI). By electron microscopy, CRF-LI was most intensely localized to large (80-100 nm) dense-core vesicles within numerous terminals and a few perikarya and large dendrites. Approximately half of the terminals containing CRF-LI were in direct contact with unlabeled perikarya or dendrites; the remainder were in apposition to either unlabeled terminals or astrocytes. Most synaptic specializations were asymmetric synapses on small, unlabeled dendrites. To examine potential extrinsic sources of CRF- containing terminals in the C1 area of the RVL, PAP immunocytochemical localization of CRF was combined with retrograde transport of wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP). In all cases examined, a number of dually labeled neurons were found in the paraventricular nucleus (PVN) of the hypothalamus and a few dually labeled neurons were observed in the nuclei of the solitary tract; these labeled neurons were ipsilateral to the unilateral injection of WGA-HRP into the C1 area. Fewer dually labeled perikarya were detected in the lateral hypothalamic area and the lateral parabrachial nuclei, ipsilateral to the WGA-HRP injection. Additional physiological studies showed that bilateral microinjections of CRF into the C1 area of the RVL of urethane-anesthetized rats elicited a dose-related increase in arterial pressure. The results suggest that within the C1 area of the RVL, CRF released from terminals, arising predominantly from the PVN of the hypothalamus and probably from local neurons as well, may excite sympathoexcitatory reticulospinal neurons.

KW - C1 area

KW - electron microscopy

KW - paraventricular nucleus of the hypothalamus

UR - http://www.scopus.com/inward/record.url?scp=0027212663&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027212663&partnerID=8YFLogxK

M3 - Article

C2 - 7688383

AN - SCOPUS:0027212663

VL - 333

SP - 151

EP - 167

JO - Journal of Comparative Neurology

JF - Journal of Comparative Neurology

SN - 0021-9967

IS - 2

ER -