Indirect influences of gonadal hormones on sexual differentiation

1998 ◽  
Vol 21 (3) ◽  
pp. 337-338
Author(s):  
Lesley J. Rogers
Keyword(s):  
Sexual Differentiation ◽  
Gonadal Hormones ◽  
Hormonal Condition ◽  
The Way

Indirect routes by which gonadal hormones influence sexual differentiation are considered. In rats, differentiation may depend on the way in which the mother responds to the hormonal condition of her pups, and this has implications for the interpretation of the data for humans. Interaction between gonadal hormones and light experience in chicks is compared with the mammalian systems covered in Fitch & Denenberg's review.

The Death of Siblings

2018 ◽  
pp. 88-106
Author(s):  
Raphael A. Cadenhead
Keyword(s):  
Sexual Differentiation ◽  
Moral Life ◽  
The Other ◽  
Middle Phase ◽  
Male And Female ◽  
Genesis 1 ◽  
The Impact ◽  
The Way

Chapter 5 considers the impact of the death of two of Gregory’s siblings, Basil and Macrina, on his ascetical theology. It begins with an analysis of the much-disputed question of the restoration of human genitalia in Gregory’s account of the general resurrection. The author argues that there are two rival anthropologies at play (one based on Genesis 1:27a–b, the other on Genesis 2), which offer different perspectives on the eschatological finality of sexual differentiation. Looking at Gregory’s writings diachronically reveals why these two anthropologies came into contact with each other during the middle phase of his literary career and why they do not reach a point of resolution or synthesis in his theorization on the restoration of human genitalia. These discussions of embodied difference prepare the way for a consideration of their spiritual and moral associations. By drawing attention to the neglected figure of Naucratius, one of Gregory’s brothers, who “overcame” his “manhood” to make advancements in the moral life, the author argues that male virility, for Gregory, needs to be renounced in the moral life just as much as female passion. Both male and female characteristics, which are deeply embedded in the fallen state of humanity, need to be chastened and transformed through the bodily disciplines of the ascetic life.

Gonadal hormone effects on entrained and free-running circadian activity rhythms in the developing diurnal rodent Octodon degus

2007 ◽  
Vol 292 (1) ◽  
pp. R586-R597 ◽  
Author(s):  
Daniel L. Hummer ◽  
Tammy J. Jechura ◽  
Megan M. Mahoney ◽  
Theresa M. Lee
Keyword(s):  
Sex Differences ◽  
Sex Difference ◽  
Sexual Differentiation ◽  
Gonadal Hormones ◽  
Circadian System ◽  
System Structure ◽  
Octodon Degus ◽  
Activity Rhythms ◽  
Free Running ◽  
The Impact

The slowly maturing, long-lived rodent Octodon degus (degu) provides a unique opportunity to examine the development of the circadian system during adolescence. These studies characterize entrained and free-running activity rhythms in gonadally intact and prepubertally gonadectomized male and female degus across the first year of life to clarify the impact of sex and gonadal hormones on the circadian system during adolescence. Gonadally intact degus exhibited a delay in the phase angle of activity onset (Ψon) during puberty, which reversed as animals became reproductively competent. Gonadectomy before puberty prevented this phase delay. However, the effect of gonadal hormones during puberty on Ψon does not result from changes in the period of the underlying circadian pacemaker. A sex difference in Ψon and free-running period (τ) emerged several months after puberty; these developmental changes are not likely to be related, since the sex difference in Ψon emerged before the sex difference in τ. Changes in the levels of circulating hormones cannot explain the emergence of these sex differences, since there is a rather lengthy delay between the age at which degus reach sexual maturity and the age at which Ψon and τ become sexually dimorphic. However, postnatal exposure to gonadal hormones is required for sexual differentiation of Ψon and τ, since these sex differences were absent in prepubertally gonadectomized degus. These data suggest that gonadal hormones modulate the circadian system during adolescent development and provide a new model for postpubertal sexual differentiation of a central nervous system structure.

The 13th J. A. F. Stevenson Memorial Lecture Sexual differentiation of the brain: possible mechanisms and implications

1985 ◽  
Vol 63 (6) ◽  
pp. 577-594 ◽  
Author(s):  
Roger A. Gorski
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Sex Differences ◽  
Sexual Differentiation ◽  
Gonadal Hormones ◽  
Model Systems ◽  
Memorial Lecture ◽  
Actual Structure ◽  
The Central Nervous System ◽  
The Brain

The mammalian brain appears to be inherently feminine and the action of testicular hormones during development is necessary for the differentiation of the masculine brain both in terms of functional potential and actual structure. Experimental evidence for this statement is reviewed in this discussion. Recent discoveries of marked structural sex differences in the central nervous system, such as the sexually dimorphic nucleus of the preoptic area in the rat, offer model systems to investigate potential mechanisms by which gonadal hormones permanently modify neuronal differentiation. Although effects of these steroids on neurogenesis and neuronal migration and specification have not been conclusively eliminated, it is currently believed, but not proven, that the principle mechanism of steroid action is to maintain neuronal survival during a period of neuronal death. The structural models of the sexual differentiation of the central nervous system also provide the opportunity to identify sex differences in neurochemical distribution. Two examples in the rat brain are presented: the distribution of serotonin-immunoreactive fibers in the medial preoptic nucleus and of tyrosine hydroxylase-immunoreactive fibers and cells in the anteroventral periventricular nucleus. It is likely that sexual dimorphisms will be found to be characteristic of many neural and neurochemical systems. The final section of this review raises the possibility that the brain of the adult may, in response to steroid action, be morphologically plastic, and considers briefly the likelihood that the brain of the human species is also influenced during development by the hormonal environment.

Interaction of sex chromosome complement, gonadal hormones and neuronal steroid synthesis on the sexual differentiation of mammalian neurons

2017 ◽  
Vol 31 (4) ◽  
pp. 300-306 ◽  
Author(s):  
Maria Julia Cambiasso ◽  
Carla Daniela Cisternas ◽  
Isabel Ruiz-Palmero ◽  
Maria Julia Scerbo ◽  
Maria Angeles Arevalo ◽  
...  
Keyword(s):  
Sexual Differentiation ◽  
Sex Chromosome ◽  
Chromosome Complement ◽  
Gonadal Hormones ◽  
Steroid Synthesis

Sex-dependent endorphinergic and adrenergic control mechanisms of luteinizing hormone secretion in immature rats

1985 ◽  
Vol 109 (2) ◽  
pp. 198-203 ◽  
Author(s):  
Rüdiger Schulz ◽  
Annemarie Wilhelm ◽  
Karl Martin Pirke ◽  
Albert Herz
Keyword(s):  
Luteinizing Hormone ◽  
Sexual Differentiation ◽  
Post Partum ◽  
Hormone Secretion ◽  
Gonadal Hormones ◽  
Control Mechanisms ◽  
Male And Female ◽  
Immature Rats ◽  
Adrenergic Control ◽  
The Brain

Abstract. Previous studies in male and female immature rats have revealed striking sex differences as concerns endorphinergic and adrenergic control of luteinizing hormone (LH) secretion. The present study examines in 10 days old male and females rats whether these differences result from sexual differentiation of the brain, or acute effects of male and female gonadal hormones. The techniques employed to manipulate these mechanisms were gonadectomy immediately post-partum and androgenization. Androgenization on the 1st and 2nd day of life reduces the ability of naloxone to elevate serum LH levels in females, but failed to modify the LH-elevating effect of clonidine in males. Experiments with castrates showed that testosterone is critical for these sex-related differences. Treatment with testosterone on the 9th day of life of intact or gonadectomized rats revealed the ability of this hormone to modify LH-release acutely. We conclude that sexual differentiation of the brain may be of minor significance for the sex-related LH-control mechanisms in prepubertal rats. Of importance is the acute presence of testosterone, since in its absence male characteristics disappear.

Sry, more than testis determination?

2011 ◽  
Vol 301 (3) ◽  
pp. R561-R571 ◽  
Author(s):  
Monte E. Turner ◽  
Daniel Ely ◽  
Jeremy Prokop ◽  
Amy Milsted
Keyword(s):  
Nervous System ◽  
Sexual Differentiation ◽  
System Development ◽  
Quantitative Difference ◽  
Gonadal Hormones ◽  
Nervous System Development ◽  
Adult Males ◽  
Functional Consequences ◽  
Testis Determination ◽  
Developmental Switch

The Sry locus on the mammalian Y chromosome is the developmental switch responsible for testis determination. Inconsistent with this important function, the Sry locus is transcribed in adult males at times and in tissues not involved with testis determination. Sry is expressed in multiple tissues of the peripheral and central nervous system. Sry is derived from Sox3 and is similar to other SOXB family loci. The SOXB loci are responsible for nervous system development. Sry has been demonstrated to modulate the catecholamine pathway, so it should have functional consequences in the central and peripheral nervous system. The nervous system expression and potential function are consistent with Sry as a SOXB family member. In mammals, Sox3 is X-linked and undergoes dosage compensation in females. The expression of Sry in adult males allows for a type of sexual differentiation independent of circulating gonadal hormones. A quantitative difference in Sox3 plus Sry expression in males vs. females could drive changes in the transcriptome of these cells, differentiating male and female cells. Sry expression and its transcriptional effects should be considered when investigating sexual dimorphic phenotypes.

Sign in / Sign up

Export Citation Format

Share Document