Hormone-Induced Sexual Differentiation of Brain and Behavior in Zebra Finches

  title={Hormone-Induced Sexual Differentiation of Brain and Behavior in Zebra Finches},
  author={M. Gurney and M. Konishi},
  pages={1380 - 1383}
The male zebra finch sings, whereas the female does not. This behavioral dimorphism is correlated with the presence of morphological sex differences within the neural substrate that mediates this behavior, the song system. When a female chick is exposed to 17β-estradiol her song system is subsequently masculinized. Either testosterone or 5α-dihydrotestosterone may then induce such a female to sing when an adult. 
Behavioral correlates of sexual differentiation in the zebra finch song system
The capacity for song is masculinized in female zebra finches by exposure to 17 beta-estradiol at hatching, and requires continual exposure to androgen for its behavioral expression in the adult. TheExpand
The correlation between the degree of brain masculinization and song quality in estradiol treated female zebra finches
The anatomy of two song nuclei is compared with the birds' song quality and the capacity for song correlates with the volumes of the nucleus hyperstriatum, ventralis, pars caudalis, HVc and the nucleus robustus archistriatalis and with the size of RA neurons. Expand
Reanalyzing the role of estradiol in the developing zebra finch brain
In zebra finches, many features of the neural song system are more pronounced in males compared to females. The exact mechanism(s) responsible for these differences are not known, but potentiallyExpand
Estrogen establishes sex differences in androgen accumulation in zebra finch brain
It is suggested that early E2 exposure renders the female song system neuroanatomically and functionally responsive to androgens, and E2 establishes this responsiveness by regulating the number of androgen target neurons within MAN and HVc. Expand
Sexual differentiation of brain and behavior in quail and zebra finches: Studies with a new aromatase inhibitor, R76713
It was proposed that the male reproductive phenotype is "neutral" in birds and that endogenous estradiol secreted by the ovary of the female embryo is responsible for the physiological demasculinization of females and this model could be recently confirmed. Expand
Neither testicular androgens nor embryonic aromatase activity alters morphology of the neural song system in zebra finches.
It is found that treating embryonic female zebra finches with fadrozole, a potent aromatase inhibitor, can induce testicular tissue to develop in addition to normal ovarian tissue, and shows that it secretes androgens in adulthood, produces sperm, and causes the androgen-sensitive syrinx to enlarge. Expand
Sexual differentiation of behavior in the zebra finch: Effect of early gonadectomy or androgen treatment
Androgens appear to have less influence than estrogens on sexual differentiation of behavior in this species, and the combination of DHTP and EB demasculinized mounting in males. Expand
Zebra finch sexual differentiation: The aromatization hypothesis revisited
  • J. Wade
  • Biology, Medicine
  • Microscopy research and technique
  • 2001
The evidence relating to the role of gonadal steroids in the sexual differentiation of reproductive behaviors and the central and peripheral structures known to regulate them in zebra finches are reviewed, with a focus on estradiol, which has been most extensively studied in the masculinization of song system morphology and function. Expand
Testosterone Metabolism and Sexual Differentiation in Quail
In higher vertebrates, sexual dimorphism is a widespread phenomenon and males and females usually differ in their behaviour and endocrine physiology. Expand
Post-hatching inhibition of aromatase activity does not alter sexual differentiation of the zebra finch song system
The results argue against the importance of estrogen in masculinization of the song system in males after hatching. Expand


Sexual Difference in Pattern of Hormone Accumulation in the Brain of a Songbird
After adult zebra finches (Poephila guttata) received injections of tritiated testosterone, fewer hormone-concentrating cells were found in females than in males in two brain regions involved inExpand
Sexual dimorphism in vocal control areas of the songbird brain.
In canaries and zebra finches, three vocal control areas in the brain are strikingly larger in males than in females, believed to be the first report of such gross sexual dimorphism in a vertebrate brain. Expand
Sex differences in dendritic patterns in hamster preoptic area
Results suggest sex differences in the afferent inputs to neurons in the dorsomedial preoptic area which may be related to functional sexual dimorphism in physiology and behavior. Expand
Organizing action of prenatally administered testosterone propionate on the tissues mediating mating behavior in the female guinea pig.
The sexual behavior of male and female guinea pigs from mothers receiving testosterone propionate during most of pregnancy was studied after the attainment of adulthood and the capacity to display lordosis following administration of estrogen and progesterone was greatly reduced. Expand
Phylogenetic distribution of aromatase and other androgen-converting enzymes in the central nervous system.
Comparisons with previously reported comparative studies indicate that the ability to aromatize and otherwise transform androgen substrates is a primitive characteristic of the brain that has been widely conserved phylogenetically. Expand
Hormone concentrating cells in vocal control and other areas of the brain of the zebra finch (Poephila guttata)
Using the autoradiographic method in the zebra finch (Poephila guttata), areas of the brain were identified which contain cells which accumulate testosterone or its metabolites after intramuscularExpand
Electrophysiological evidence for sexual dimorphism and synaptic convergence in the preoptic and anterior hypothalamic areas of the rat
The sex dependent properties of two categories of neurone are related to endocrine status and not genetic sex, the male situation being induced by exposure of the brain to androgen during the critical perinatal period. Expand
Central control of song in the canary, Serinus canarius
Central nervous pathways controlling bird son in the canary are traced using a combination of behavioral and anatomical techniques and direct connections were found onto the cells of the motor nucleus innervating the syrinx, the organ of song production. Expand
Anovulation in adult female rats after neonatal intracerebral implantation of oestrogen.
The findings demonstrate that the delayed anovulatory syndrome can be induced in female rats by the neonatal intrahypothalamic implantation of a very low dose of OB, and that the corticomedial amygdala seems not to be a site of oestrogen action in this sterilizing effect. Expand
Sexual dimorphism in the neuropil of the preoptic area of the rat and its dependence on neonatal androgen.
In normal females the number of non-amygdaloid synapses on dendritic spines in the preoptic area is higher than in the male, and the suggestion that this difference could be related to the ability of the female to maintain a cyclic pattern of gonadotrophin release and/or behavioural oestrus is supported by published work implicating the pre optic area in the control of ovulation and mating behaviour. Expand