Hormonal and environmental control of song control region growth and new neuron addition in adult male house finches, Carpodacus mexicanus

Christine R. Strand, Pierre Deviche

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

In songbirds, testosterone (T) mediates seasonal changes in the sizes and neuroanatomical characteristics of brain regions that control singing (song control regions; SCRs). One model explaining the mechanisms of the growth of one SCR, the HVC, postulates that in the spring increasing photoperiod and circulating T concentrations enhance new neuron survival, thus increasing total neuron number. However, most research investigating the effects of T on new neuron survival has been done in autumn. The present study investigated the effects of photoperiod and T treatment on SCR growth and new neuron survival in the HVC in photosensitive adult male House Finches, Carpodacus mexicanus, under simulated spring-like conditions. Birds were castrated, given T-filled or empty Silastic capsules and maintained on short days (SD; 8L:16D) or long days (LD; 16L:8D). To mark new cells, birds received bromodeoxyuridine injections 11 days after experimental manipulations began and were sacrificed 28 days later. Testosterone treatment increased the sizes of two SCRs, the HVC and Robust nucleus of the arcopallium (RA). Exposure to LD did not affect HVC volume, but did increase RA volume. Testosterone treatment increased the total number of HVC neurons, but did not affect the number of new HVC neurons. Thus, T initiates SCR growth and increases neuron survival, but effects of T on new neuron incorporation may be limited in photosensitive birds under spring-like conditions. These results provide new insight into the effects of photoperiod and T treatment on vernal SCR growth and new neuron incorporation and support current models explaining this growth.

Original languageEnglish (US)
Pages (from-to)827-837
Number of pages11
JournalDevelopmental Neurobiology
Volume67
Issue number6
DOIs
StatePublished - May 2007

Fingerprint

Finches
Music
Neurons
Growth
Photoperiod
Birds
Testosterone
Singing
Songbirds
Bromodeoxyuridine
Therapeutics
Capsules
Injections

Keywords

  • HVC
  • Neurogenesis
  • Photoperiod
  • Songbird
  • Testosterone

ASJC Scopus subject areas

  • Cellular and Molecular Neuroscience
  • Developmental Neuroscience
  • Neuroscience(all)

Cite this

@article{3ecad636d3c4443381a8255fd4b92da4,
title = "Hormonal and environmental control of song control region growth and new neuron addition in adult male house finches, Carpodacus mexicanus",
abstract = "In songbirds, testosterone (T) mediates seasonal changes in the sizes and neuroanatomical characteristics of brain regions that control singing (song control regions; SCRs). One model explaining the mechanisms of the growth of one SCR, the HVC, postulates that in the spring increasing photoperiod and circulating T concentrations enhance new neuron survival, thus increasing total neuron number. However, most research investigating the effects of T on new neuron survival has been done in autumn. The present study investigated the effects of photoperiod and T treatment on SCR growth and new neuron survival in the HVC in photosensitive adult male House Finches, Carpodacus mexicanus, under simulated spring-like conditions. Birds were castrated, given T-filled or empty Silastic capsules and maintained on short days (SD; 8L:16D) or long days (LD; 16L:8D). To mark new cells, birds received bromodeoxyuridine injections 11 days after experimental manipulations began and were sacrificed 28 days later. Testosterone treatment increased the sizes of two SCRs, the HVC and Robust nucleus of the arcopallium (RA). Exposure to LD did not affect HVC volume, but did increase RA volume. Testosterone treatment increased the total number of HVC neurons, but did not affect the number of new HVC neurons. Thus, T initiates SCR growth and increases neuron survival, but effects of T on new neuron incorporation may be limited in photosensitive birds under spring-like conditions. These results provide new insight into the effects of photoperiod and T treatment on vernal SCR growth and new neuron incorporation and support current models explaining this growth.",
keywords = "HVC, Neurogenesis, Photoperiod, Songbird, Testosterone",
author = "Strand, {Christine R.} and Pierre Deviche",
year = "2007",
month = "5",
doi = "10.1002/dneu.20400",
language = "English (US)",
volume = "67",
pages = "827--837",
journal = "Developmental Neurobiology",
issn = "1932-8451",
publisher = "John Wiley and Sons Inc.",
number = "6",

}

TY - JOUR

T1 - Hormonal and environmental control of song control region growth and new neuron addition in adult male house finches, Carpodacus mexicanus

AU - Strand, Christine R.

AU - Deviche, Pierre

PY - 2007/5

Y1 - 2007/5

N2 - In songbirds, testosterone (T) mediates seasonal changes in the sizes and neuroanatomical characteristics of brain regions that control singing (song control regions; SCRs). One model explaining the mechanisms of the growth of one SCR, the HVC, postulates that in the spring increasing photoperiod and circulating T concentrations enhance new neuron survival, thus increasing total neuron number. However, most research investigating the effects of T on new neuron survival has been done in autumn. The present study investigated the effects of photoperiod and T treatment on SCR growth and new neuron survival in the HVC in photosensitive adult male House Finches, Carpodacus mexicanus, under simulated spring-like conditions. Birds were castrated, given T-filled or empty Silastic capsules and maintained on short days (SD; 8L:16D) or long days (LD; 16L:8D). To mark new cells, birds received bromodeoxyuridine injections 11 days after experimental manipulations began and were sacrificed 28 days later. Testosterone treatment increased the sizes of two SCRs, the HVC and Robust nucleus of the arcopallium (RA). Exposure to LD did not affect HVC volume, but did increase RA volume. Testosterone treatment increased the total number of HVC neurons, but did not affect the number of new HVC neurons. Thus, T initiates SCR growth and increases neuron survival, but effects of T on new neuron incorporation may be limited in photosensitive birds under spring-like conditions. These results provide new insight into the effects of photoperiod and T treatment on vernal SCR growth and new neuron incorporation and support current models explaining this growth.

AB - In songbirds, testosterone (T) mediates seasonal changes in the sizes and neuroanatomical characteristics of brain regions that control singing (song control regions; SCRs). One model explaining the mechanisms of the growth of one SCR, the HVC, postulates that in the spring increasing photoperiod and circulating T concentrations enhance new neuron survival, thus increasing total neuron number. However, most research investigating the effects of T on new neuron survival has been done in autumn. The present study investigated the effects of photoperiod and T treatment on SCR growth and new neuron survival in the HVC in photosensitive adult male House Finches, Carpodacus mexicanus, under simulated spring-like conditions. Birds were castrated, given T-filled or empty Silastic capsules and maintained on short days (SD; 8L:16D) or long days (LD; 16L:8D). To mark new cells, birds received bromodeoxyuridine injections 11 days after experimental manipulations began and were sacrificed 28 days later. Testosterone treatment increased the sizes of two SCRs, the HVC and Robust nucleus of the arcopallium (RA). Exposure to LD did not affect HVC volume, but did increase RA volume. Testosterone treatment increased the total number of HVC neurons, but did not affect the number of new HVC neurons. Thus, T initiates SCR growth and increases neuron survival, but effects of T on new neuron incorporation may be limited in photosensitive birds under spring-like conditions. These results provide new insight into the effects of photoperiod and T treatment on vernal SCR growth and new neuron incorporation and support current models explaining this growth.

KW - HVC

KW - Neurogenesis

KW - Photoperiod

KW - Songbird

KW - Testosterone

UR - http://www.scopus.com/inward/record.url?scp=34250885687&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=34250885687&partnerID=8YFLogxK

U2 - 10.1002/dneu.20400

DO - 10.1002/dneu.20400

M3 - Article

C2 - 17443828

AN - SCOPUS:34250885687

VL - 67

SP - 827

EP - 837

JO - Developmental Neurobiology

JF - Developmental Neurobiology

SN - 1932-8451

IS - 6

ER -