Dataset Information

Estrogenic regulation of dopaminergic neurons in the opportunistically breeding zebra finch.

ABSTRACT: Steroid-induced changes in dopaminergic activity underlie many correlations between gonadal hormones and social behaviors. However, the effects of steroid hormones on the various behaviorally relevant dopamine cell groups remain unclear, and ecologically relevant species differences remain virtually unexplored. We examined the effects of estradiol (E2) manipulations on dopamine (DA) neurons of male and female zebra finches (Taeniopygia guttata), focusing on numbers of tyrosine hydroxylase-immunoreactive (TH-ir) cells in the A8-A15 cell groups, and on TH colocalization with Fos, conducted in the early A.M., in order to quantify basal transcriptional activity. TH is the rate-limiting enzyme for catecholamine synthesis, and specifically DA in the A8-A15 cell groups. In contrast to other examined birds and mammals, reducing E2 levels with the aromatase-inhibitor Letrozole failed to alter TH-ir neuron numbers within the ventral tegmental area (VTA; A10), while increasing neuron numbers in the central gray (CG; A11) and caudal midbrain A8 populations. Consistent with findings in other birds, but not mammals, we also found no effects of E2 manipulations (Letrozole or Letrozole plus E2 replacement) on TH-Fos colocalization in any location. In accordance with previous observations in both mammals and birds, E2 treatment decreased the number of TH-ir neurons in the A12 population of the tuberal hypothalamus, a cell group that inhibits the release of prolactin. In general, males and females exhibited similar TH-ir neuron numbers, although males exhibited significantly more TH-ir neurons in the A11 CG population than did females. These results suggest partial variability in E2 regulation of DA across species.

SUBMITTER: Kabelik D

PROVIDER: S-EPMC3130106 | biostudies-literature | 2011 Aug

REPOSITORIES: biostudies-literature

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Estrogenic regulation of dopaminergic neurons in the opportunistically breeding zebra finch.

Kabelik David D Schrock Sara E SE Ayres Lauren C LC Goodson James L JL

General and comparative endocrinology 20110510 1

Steroid-induced changes in dopaminergic activity underlie many correlations between gonadal hormones and social behaviors. However, the effects of steroid hormones on the various behaviorally relevant dopamine cell groups remain unclear, and ecologically relevant species differences remain virtually unexplored. We examined the effects of estradiol (E2) manipulations on dopamine (DA) neurons of male and female zebra finches (Taeniopygia guttata), focusing on numbers of tyrosine hydroxylase-immuno ...[more]

PMID: 21600208

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Project description:Like human speech, birdsong is a complex vocal behavior that is acquired by sensorimotor learning based on coordination of auditory input and vocal output to mimic memorized tutor song. Here we investigate neural circuits for vocal learning and production in deafened songbirds to elucidate how sensory-input regulate genetic and epigenetic property of vocal development and its associated gene expression dynamics. Compared with audition-intact birds, in deafened zebra finches, the vocal development is delayed but song crystallization is observed at more than three times later, producing individually different but structured vocal patterns. In contrast to the distinct difference of vocal ontogeny between audition (+) and (-), unexpectedly, developmental regulation of gene expression dynamics is strictly conserved with age-locked trend in vocal motor circuit in both intact and deafened birds, indicating sensory-input independent robustness of developmental gene expression dynamics in the motor circuit for sensorimotor learning. This discrepancy between outward vocal phenotype and inward gene expression dynamics provides new insight into neural regulation at closing of the critical period for vocal learning by two different forms: auditory inputs-dependent M-bM-^@M-^XactiveM-bM-^@M-^Y crystallization and gene expression dynamics-mediated M-bM-^@M-^XpassiveM-bM-^@M-^Y crystallization. We collected brain samples from intact and early-deafened birds (deafened at day-post hatch 17-23) under silent and dark condition. Song nuclei in vocal motor circuit, HVC and RA tissue samples (juvenile; n = 3, young; n = 3, old; n = 3 of intact and early-deafened birds for HVC and RA) were laser-microdissected from total 24 birds (intact; n = 12, early-deafened; n = 12). Each sample was hybridized to a single array, totaling 36 arrays. Birds were selected per slide such that early-deafened birds were paired with intact birds. To minimize possible interslide bias or batch effects, intact and early-deafened bird samples matching with brain area and age conditions were hybridized side by side on same array glass.

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Dataset Information

Estrogenic regulation of dopaminergic neurons in the opportunistically breeding zebra finch.

Publications

Estrogenic regulation of dopaminergic neurons in the opportunistically breeding zebra finch.

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