TY - JOUR
T1 - Central prolactin binding site densities change seasonally in an adult male passerine bird (Junco hyemalis)
AU - Smiley, Kristina O.
AU - Buntin, John D.
AU - Corbitt, Cynthia
AU - Deviche, Pierre
N1 - Funding Information:
This work was supported by NIMH, United States of America grant 41447. Purified ovine prolactin was obtained from National Hormone and Pituitary Program NIDDK.
Funding Information:
This work was supported by NIMH, United States of America grant 41447 . Purified ovine prolactin was obtained from National Hormone and Pituitary Program NIDDK.
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/7
Y1 - 2020/7
N2 - Seasonal reproduction is common across temperate zone avian species. In these species, physiological and behavioral adaptations have evolved to change according to day length (i.e., seasonally) in order to maximize reproductive output. The hormone prolactin regulates many aspects of parental care, a critical component of reproductive success. It's secretion in birds has been shown to be under photoperiodic control, with the highest levels measured in the spring and summer months, when birds breed and show parental care. However, to date, no study has tested whether the densities of central prolactin binding sites vary seasonally, which may also account for prolactin's effect on parental care. To test this, we collected brains from free-ranging adult male dark-eyed juncos, Junco hyemalis, a biparental songbird, in the spring, summer, and fall, and used quantitative in vitro autoradiography to compare the densities of specific prolactin binding sites across 20 different brain regions. Prolactin binding sites were found in regions that regulate parental behavior in other avian species. During the summer, several hypothalamic regions that regulate parental care, including the preoptic area and tuberal nucleus, contained lower densities of prolactin binding sites, suggesting exposure to higher endogenous prolactin levels, than at other times. This observation is consistent with the fact that circulating prolactin is highest during summer, when males would be providing care to young. Overall, these data suggest that prolactin binding sites are relatively conserved in the avian brain and that central prolactin activity supports parental care efforts in juncos and other avian species.
AB - Seasonal reproduction is common across temperate zone avian species. In these species, physiological and behavioral adaptations have evolved to change according to day length (i.e., seasonally) in order to maximize reproductive output. The hormone prolactin regulates many aspects of parental care, a critical component of reproductive success. It's secretion in birds has been shown to be under photoperiodic control, with the highest levels measured in the spring and summer months, when birds breed and show parental care. However, to date, no study has tested whether the densities of central prolactin binding sites vary seasonally, which may also account for prolactin's effect on parental care. To test this, we collected brains from free-ranging adult male dark-eyed juncos, Junco hyemalis, a biparental songbird, in the spring, summer, and fall, and used quantitative in vitro autoradiography to compare the densities of specific prolactin binding sites across 20 different brain regions. Prolactin binding sites were found in regions that regulate parental behavior in other avian species. During the summer, several hypothalamic regions that regulate parental care, including the preoptic area and tuberal nucleus, contained lower densities of prolactin binding sites, suggesting exposure to higher endogenous prolactin levels, than at other times. This observation is consistent with the fact that circulating prolactin is highest during summer, when males would be providing care to young. Overall, these data suggest that prolactin binding sites are relatively conserved in the avian brain and that central prolactin activity supports parental care efforts in juncos and other avian species.
KW - Diencephalon
KW - Hypothalamus
KW - Junco
KW - Prolactin
KW - Prolactin receptor
KW - Reproduction
KW - Seasonality
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U2 - 10.1016/j.jchemneu.2020.101786
DO - 10.1016/j.jchemneu.2020.101786
M3 - Article
C2 - 32278635
AN - SCOPUS:85083497907
SN - 0891-0618
VL - 106
JO - Journal of Chemical Neuroanatomy
JF - Journal of Chemical Neuroanatomy
M1 - 101786
ER -