Changes in brain gonadotropin-releasing hormone- and vasoactive intestinal polypeptide-like immunoreactivity accompanying reestablishment of photosensitivity in male dark-eyed juncos (Junco hyemalis)

Pierre Deviche, Colin J. Saldanha, Rae Silver

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

In seasonally breeding, photoperiodic birds, the development of photorefractoriness is associated with decreased brain expression of gonadotropin-releasing hormone-like immunoreactivity (GnRH-li ir) and increased expression of vasoactive intestinal polypeptide-like immunoreactivity (VIP-li ir). Dissipation of photorefractoriness and reestablishment of photosensitivity are associated with increased GnRH-li ir brain production, but concurrent changes in VIP-li ir expression have not been investigated. To address this question, we compared the expression of VIP-Ii ir in the infundibulum (INF) of adult male dark-eyed juncos (Junco hyemalis) that were made photorefractory (PR) by prolonged exposure to long days with that of birds that were not photostimulated (PS), but had regained photosensitivity by exposure to short days for 5 (short-term-PS, ST-PS) or 13 (long-term-PS, LT-PS) consecutive months. Photosensitive males had smaller INF VIP-Ii ir cell bodies than PR males, but the numbers of INF VIP-li ir cells were independent of photoperiodic condition. Changes in infundibular VIP-li ir were correlated with changes in preoptic area (POA) GnRH-li expression. Specifically, photosensitive males had more and larger POA GnRH- li ir cells and more GnRH-li ir fibers in this region than PR males. Further, LT-PS males had more GnRH-li ir POA fibers and larger testes than ST-PS juncos. Thus, induction of photorefractoriness is associated with increased VIP and decreased GnRH brain expression whereas dissipation of photorefractoriness concurs with decreased VIP and increased GnRH brain expression. These results suggest a physiological role for VIP in the control of changes in GnRH expression as a function of the photosensitive condition.

Original languageEnglish (US)
Pages (from-to)8-19
Number of pages12
JournalGeneral and Comparative Endocrinology
Volume117
Issue number1
DOIs
StatePublished - Jan 2000
Externally publishedYes

Fingerprint

Junco hyemalis
vasoactive intestinal peptide
Vasoactive Intestinal Peptide
gonadotropin-releasing hormone
Gonadotropin-Releasing Hormone
preoptic area
brain
Brain
Preoptic Area
Pituitary Gland
Birds
birds
cells
photosensitivity
testes
Breeding
Testis
breeding

Keywords

  • GnRH
  • Immunocytochemistry
  • Infundibulum
  • P hotorefractoriness
  • Photoperiodism
  • Photosensitivity
  • Preoptic area
  • Prolactin
  • Reproduction
  • Seasonality
  • VIP

ASJC Scopus subject areas

  • Endocrinology

Cite this

@article{3e44c2044c1741808eeccd57822f0a2c,
title = "Changes in brain gonadotropin-releasing hormone- and vasoactive intestinal polypeptide-like immunoreactivity accompanying reestablishment of photosensitivity in male dark-eyed juncos (Junco hyemalis)",
abstract = "In seasonally breeding, photoperiodic birds, the development of photorefractoriness is associated with decreased brain expression of gonadotropin-releasing hormone-like immunoreactivity (GnRH-li ir) and increased expression of vasoactive intestinal polypeptide-like immunoreactivity (VIP-li ir). Dissipation of photorefractoriness and reestablishment of photosensitivity are associated with increased GnRH-li ir brain production, but concurrent changes in VIP-li ir expression have not been investigated. To address this question, we compared the expression of VIP-Ii ir in the infundibulum (INF) of adult male dark-eyed juncos (Junco hyemalis) that were made photorefractory (PR) by prolonged exposure to long days with that of birds that were not photostimulated (PS), but had regained photosensitivity by exposure to short days for 5 (short-term-PS, ST-PS) or 13 (long-term-PS, LT-PS) consecutive months. Photosensitive males had smaller INF VIP-Ii ir cell bodies than PR males, but the numbers of INF VIP-li ir cells were independent of photoperiodic condition. Changes in infundibular VIP-li ir were correlated with changes in preoptic area (POA) GnRH-li expression. Specifically, photosensitive males had more and larger POA GnRH- li ir cells and more GnRH-li ir fibers in this region than PR males. Further, LT-PS males had more GnRH-li ir POA fibers and larger testes than ST-PS juncos. Thus, induction of photorefractoriness is associated with increased VIP and decreased GnRH brain expression whereas dissipation of photorefractoriness concurs with decreased VIP and increased GnRH brain expression. These results suggest a physiological role for VIP in the control of changes in GnRH expression as a function of the photosensitive condition.",
keywords = "GnRH, Immunocytochemistry, Infundibulum, P hotorefractoriness, Photoperiodism, Photosensitivity, Preoptic area, Prolactin, Reproduction, Seasonality, VIP",
author = "Pierre Deviche and Saldanha, {Colin J.} and Rae Silver",
year = "2000",
month = "1",
doi = "10.1006/gcen.1999.7361",
language = "English (US)",
volume = "117",
pages = "8--19",
journal = "General and Comparative Endocrinology",
issn = "0016-6480",
publisher = "Academic Press Inc.",
number = "1",

}

TY - JOUR

T1 - Changes in brain gonadotropin-releasing hormone- and vasoactive intestinal polypeptide-like immunoreactivity accompanying reestablishment of photosensitivity in male dark-eyed juncos (Junco hyemalis)

AU - Deviche, Pierre

AU - Saldanha, Colin J.

AU - Silver, Rae

PY - 2000/1

Y1 - 2000/1

N2 - In seasonally breeding, photoperiodic birds, the development of photorefractoriness is associated with decreased brain expression of gonadotropin-releasing hormone-like immunoreactivity (GnRH-li ir) and increased expression of vasoactive intestinal polypeptide-like immunoreactivity (VIP-li ir). Dissipation of photorefractoriness and reestablishment of photosensitivity are associated with increased GnRH-li ir brain production, but concurrent changes in VIP-li ir expression have not been investigated. To address this question, we compared the expression of VIP-Ii ir in the infundibulum (INF) of adult male dark-eyed juncos (Junco hyemalis) that were made photorefractory (PR) by prolonged exposure to long days with that of birds that were not photostimulated (PS), but had regained photosensitivity by exposure to short days for 5 (short-term-PS, ST-PS) or 13 (long-term-PS, LT-PS) consecutive months. Photosensitive males had smaller INF VIP-Ii ir cell bodies than PR males, but the numbers of INF VIP-li ir cells were independent of photoperiodic condition. Changes in infundibular VIP-li ir were correlated with changes in preoptic area (POA) GnRH-li expression. Specifically, photosensitive males had more and larger POA GnRH- li ir cells and more GnRH-li ir fibers in this region than PR males. Further, LT-PS males had more GnRH-li ir POA fibers and larger testes than ST-PS juncos. Thus, induction of photorefractoriness is associated with increased VIP and decreased GnRH brain expression whereas dissipation of photorefractoriness concurs with decreased VIP and increased GnRH brain expression. These results suggest a physiological role for VIP in the control of changes in GnRH expression as a function of the photosensitive condition.

AB - In seasonally breeding, photoperiodic birds, the development of photorefractoriness is associated with decreased brain expression of gonadotropin-releasing hormone-like immunoreactivity (GnRH-li ir) and increased expression of vasoactive intestinal polypeptide-like immunoreactivity (VIP-li ir). Dissipation of photorefractoriness and reestablishment of photosensitivity are associated with increased GnRH-li ir brain production, but concurrent changes in VIP-li ir expression have not been investigated. To address this question, we compared the expression of VIP-Ii ir in the infundibulum (INF) of adult male dark-eyed juncos (Junco hyemalis) that were made photorefractory (PR) by prolonged exposure to long days with that of birds that were not photostimulated (PS), but had regained photosensitivity by exposure to short days for 5 (short-term-PS, ST-PS) or 13 (long-term-PS, LT-PS) consecutive months. Photosensitive males had smaller INF VIP-Ii ir cell bodies than PR males, but the numbers of INF VIP-li ir cells were independent of photoperiodic condition. Changes in infundibular VIP-li ir were correlated with changes in preoptic area (POA) GnRH-li expression. Specifically, photosensitive males had more and larger POA GnRH- li ir cells and more GnRH-li ir fibers in this region than PR males. Further, LT-PS males had more GnRH-li ir POA fibers and larger testes than ST-PS juncos. Thus, induction of photorefractoriness is associated with increased VIP and decreased GnRH brain expression whereas dissipation of photorefractoriness concurs with decreased VIP and increased GnRH brain expression. These results suggest a physiological role for VIP in the control of changes in GnRH expression as a function of the photosensitive condition.

KW - GnRH

KW - Immunocytochemistry

KW - Infundibulum

KW - P hotorefractoriness

KW - Photoperiodism

KW - Photosensitivity

KW - Preoptic area

KW - Prolactin

KW - Reproduction

KW - Seasonality

KW - VIP

UR - http://www.scopus.com/inward/record.url?scp=0033965657&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0033965657&partnerID=8YFLogxK

U2 - 10.1006/gcen.1999.7361

DO - 10.1006/gcen.1999.7361

M3 - Article

C2 - 10620420

AN - SCOPUS:0033965657

VL - 117

SP - 8

EP - 19

JO - General and Comparative Endocrinology

JF - General and Comparative Endocrinology

SN - 0016-6480

IS - 1

ER -