Pubertal testosterone organizes regional volume and neuronal number within the medial amygdala of adult male Syrian hamsters

Lorme, Kayla C. De; Schulz, Kalynn M.; Salas-Ramirez, Kaliris Y.; Sisk, Cheryl L.

doi:10.1016/j.brainres.2012.04.035

Cited by 51 publications

(43 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The MeA undergoes prepubertal maturation and peripubertal refinement in response to gonadal hormones that parallels the refinement of these social behaviors (Cooke, 2006). There is enlargement of the MeApd during puberty (Romeo and Sisk, 2001;Chareyron et al, 2012;De Lorme et al, 2012) that is coupled with increased synaptophysin (Zehr et al, 2006), PSD-95, and vesicular glutamate transporter 2, consistent with increased number of excitatory synaptic inputs (Cooke, 2011). Disruption of synaptic refinement in MeApd may contribute to the effects of social isolation on social behaviors.…”

Section: Discussionmentioning

confidence: 99%

“…The MeA is still maturing during the postweaning period (Schulz et al, 2009;Cooke, 2011;De Lorme et al, 2012;Bergan et al, 2014). Social isolation can stunt the maturation of other brain regions (Sanchez et al, 1995;Helmeke et al, 2001;Lapiz et al, 2003;Gos et al, 2006;Agis-Balboa et al, 2007;Gilabert-Juan et al, 2012;Makinodan et al, 2012).…”

Section: Social Isolation Impairs Medial Amygdala T Adams and Ja Rosementioning

confidence: 99%

See 1 more Smart Citation

Social Isolation During Postweaning Development Causes Hypoactivity of Neurons in the Medial Nucleus of the Male Rat Amygdala

Adams

Rosenkranz

2015

Neuropsychopharmacol

View full text Add to dashboard Cite

Children exposed to neglect or social deprivation are at heightened risk for psychiatric disorders and abnormal social patterns as adults. There is also evidence that prepubertal neglect in children causes abnormal metabolic activity in several brain regions, including the amygdala area. The medial nucleus of the amygdala (MeA) is a key region for performance of social behaviors and still undergoes maturation during the periadolescent period. As such, the normal development of this region may be disrupted by social deprivation. In rodents, postweaning social isolation causes a range of deficits in sexual and agonistic behaviors that normally rely on the posterior MeA (MeAp). However, little is known about the effects of social isolation on the function of MeA neurons. In this study, we tested whether postweaning social isolation caused abnormal activity of MeA neurons. We found that postweaning social isolation caused a decrease of in vivo firing activity of MeAp neurons, and reduced drive from excitatory afferents. In vitro electrophysiological studies found that postweaning social isolation caused a presynaptic impairment of excitatory input to the dorsal MeAp, but a progressive postsynaptic reduction of membrane excitability in the ventral MeAp. These results demonstrate discrete, subnucleus-specific effects of social deprivation on the physiology of MeAp neurons. This pathophysiology may contribute to the disruption of social behavior after developmental social deprivation, and may be a novel target to facilitate the treatment of social disorders.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Social Isolation Impairs Medial Amygdala T Adams and Ja Rosementioning

confidence: 99%

Social Isolation During Postweaning Development Causes Hypoactivity of Neurons in the Medial Nucleus of the Male Rat Amygdala

Adams

Rosenkranz

2015

Neuropsychopharmacol

View full text Add to dashboard Cite

show abstract

“…The steroid hormone ecdysone regulates transitions between developmental stages and, via other ecdysone receptor isoforms, also triggers remodelling of neurons and nonneuronal tissues during metamorphosis (27). Analogously, in vertebrates, steroid hormones also act as important regulators of neuronal remodelling, for example during puberty in mammals (28,29), effecting seasonal changes in songbirds (30), or, at the cellular level, regulating the growth of sexually dimorphic muscles and their innervating motoneurons (11,31,32). In Drosophila, we find that when the ecdysone steroid signaling pathway is selectively inhibited in single motoneurons these cells fail to extend their dendritic arbors and they do not increase the number of synaptic connections as would normally occur during larval stages, despite being embedded in an otherwise normally developing and growing network.…”

mentioning

confidence: 99%

Dendritic growth gated by a steroid hormone receptor underlies increases in activity in the developing Drosophila locomotor system

Zwart

Randlett

Evers

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

As animals grow, their nervous systems also increase in size. How growth in the central nervous system is regulated and its functional consequences are incompletely understood. We explored these questions, using the larval Drosophila locomotor system as a model. In the periphery, at neuromuscular junctions, motoneurons are known to enlarge their presynaptic axon terminals in size and strength, thereby compensating for reductions in muscle excitability that are associated with increases in muscle size. Here, we studied how motoneurons change in the central nervous system during periods of animal growth. We find that within the central nervous system motoneurons also enlarge their postsynaptic dendritic arbors, by the net addition of branches, and that these scale with overall animal size. This dendritic growth is gated on a cell-by-cell basis by a specific isoform of the steroid hormone receptor ecdysone receptor-B2, for which functions have thus far remained elusive. The dendritic growth is accompanied by synaptic strengthening and results in increased neuronal activity. Electrical properties of these neurons, however, are independent of ecdysone receptor-B2 regulation. We propose that these structural dendritic changes in the central nervous system, which regulate neuronal activity, constitute an additional part of the adaptive response of the locomotor system to increases in body and muscle size as the animal grows.development | dendrite specification | dendritic complexity

show abstract

“…A similar difference was also observed between males and females analyzed as a reference. It is known that MeA undergoes structural changes during the pubertal period in a sex-specific manner that leads to sexually dimorphic adult phenotypes in various species (24,25,31,32). In gonadally intact rats, it is reported that a greater number of neuronal cells were proliferated in the MeA during the pubertal period in males compared with females and that these sexual differences were eliminated by prepubertal gonadectomy (24).…”

Section: Discussionmentioning

confidence: 99%

“…Studies using male Syrian hamsters have reported that deprivation of testosterone during this period leads to an irreversible alteration in male-type social behaviors, tested in adults with testosterone replacement (20)(21)(22)(23). Moreover, it is known that structural sexual dimorphism in the MeA reported in adult rats and hamsters is due to irreversible changes induced by testosterone during the pubertal period (24,25). However, it is not known whether ERα may be involved in the pubertal organizational action of…”

mentioning

confidence: 99%

Pubertal activation of estrogen receptor α in the medial amygdala is essential for the full expression of male social behavior in mice

Sato

Nakata

Musatov

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Testosterone plays a central role in the facilitation of male-type social behaviors, such as sexual and aggressive behaviors, and the development of their neural bases in male mice. The action of testosterone via estrogen receptor (ER) α, after being aromatized to estradiol, has been suggested to be crucial for the full expression of these behaviors. We previously reported that silencing of ERα in adult male mice with the use of a virally mediated RNAi method in the medial preoptic area (MPOA) greatly reduced sexual behaviors without affecting aggressive behaviors whereas that in the medial amygdala (MeA) had no effect on either behavior. It is well accepted that testosterone stimulation during the pubertal period is necessary for the full expression of male-type social behaviors. However, it is still not known whether, and in which brain region, ERα is involved in this developmental effect of testosterone. In this study, we knocked down ERα in the MeA or MPOA in gonadally intact male mice at the age of 21 d and examined its effects on the sexual and aggressive behaviors later in adulthood. We found that the prepubertal knockdown of ERα in the MeA reduced both sexual and aggressive behaviors whereas that in the MPOA reduced only sexual, but not aggressive, behavior. Furthermore, the number of MeA neurons was reduced by prepubertal knockdown of ERα. These results indicate that ERα activation in the MeA during the pubertal period is crucial for male mice to fully express their male-type social behaviors in adulthood.T estosterone plays a central role in the regulation of male-type social behaviors in many mammalian species. It is known that testosterone facilitates the expression of sexual and aggressive behaviors through two kinds of actions. During the developmental period, testosterone exerts its "organizational action" to irreversibly masculinize the sexually undifferentiated brain and build the male-type neural network. In adulthood, testosterone exerts "activational action" to regulate the function of the fully masculinized neural network. As well as acting through androgen receptors (ARs), testosterone also acts through estrogen receptor (ER) α or ERβ, after being aromatized to estradiol (E2). Because the expression of sexual and aggressive behaviors is greatly reduced in aromatase knockout (ArKO) and ERα knockout (αERKO) male mice, aromatization of testosterone and its action via ERα have been suggested to be crucial for the facilitation of male-type social behaviors in mice (1-8). However, the exact timing and brain site(s) of ERα activation crucial for the expression of sexual and aggressive behaviors remain undetermined.In our previous study, we demonstrated site-specific involvement of ERα in the activational action of testosterone by using a virally mediated RNAi method. In this study, knocking down of ERα in the medial preoptic area (MPOA) of gonadally intact adult male mice suppressed sexual behavior while in the ventromedial nucleus (VMN) of hypothalamus reduced both sexual and aggressive behaviors...

show abstract

Pubertal testosterone organizes regional volume and neuronal number within the medial amygdala of adult male Syrian hamsters

Cited by 51 publications

References 33 publications

Social Isolation During Postweaning Development Causes Hypoactivity of Neurons in the Medial Nucleus of the Male Rat Amygdala

Social Isolation During Postweaning Development Causes Hypoactivity of Neurons in the Medial Nucleus of the Male Rat Amygdala

Dendritic growth gated by a steroid hormone receptor underlies increases in activity in the developing Drosophila locomotor system

Pubertal activation of estrogen receptor α in the medial amygdala is essential for the full expression of male social behavior in mice

Contact Info

Product

Resources

About