Testosterone reactivity is associated with reduced neural response to reward in early adolescence

Raging Hormones: Why Age-Based Etiological Conceptualizations of the Development of Antisocial Behavior Are Insufficient

Developmental science, particularly developmental neuroscience, has substantially influenced the modern legal system. However, this science has typically failed to consider the role of puberty and pubertal hormones on development when considering antisocial behavior. This review describes major theoretical positions on the developmental neuroscience of antisocial behavior and highlights where basic developmental neuroscience suggests that the role of puberty and pubertal hormones should be considered. The implications of the current state of the science with respect to developmental neuroscience is considered, particularly what is known in light of development beyond puberty. This review shows that development continues to an older age for many youth than the legal system typically acknowledges. The plasticity of the brain that this continued development implies has implications for the outcome of interventions in the legal system in ways that have not been explored. Future directions for both developmental scientists and legal professions are recommended.

Testosterone and estradiol affect adolescent reinforcement learning

During adolescence, gonadal hormones influence brain maturation and behavior. The impact of 17β-estradiol and testosterone on reinforcement learning was previously investigated in adults, but studies with adolescents are rare. We tested 89 German male and female adolescents (mean age ± sd = 14.7 ± 1.9 years) to determine the extent 17β-estradiol and testosterone influenced reinforcement learning capacity in a response time adjustment task. Our data showed, that 17β-estradiol correlated with an enhanced ability to speed up responses for reward in both sexes, while the ability to wait for higher reward correlated with testosterone primary in males. This suggests that individual differences in reinforcement learning may be associated with variations in these hormones during adolescence, which may shift the balance between a more reward- and an avoidance-oriented learning style.

Appropriate supplementation of testosterone alleviates post-stroke damage via decreasing inflammation and oxidative stress in aged male C57BL/6 mice

Stroke injury is closely related to testosterone levels. Testosterone supplementation in elderly men is seen to protect the cardiovascular system and reduce the risk of stroke. But this medication method is controversial. This study aims to investigate the effect of long-term testosterone supplementation on brain injury after stroke in aged mice. 60 male C57BL/6 mice,12-months of age were divided into 3 groups: low-dose group, high-dose group, and control group, each group was injected subcutaneously with 100 μL of sesame oil or 5 mg/kg or 50 mg/kg of testosterone (in 100 μL of sesame oil) twice per week, respectively. One week after the injection, stroke was induced by light. After the stroke, the injection continued for 6 weeks. The motion ability was measured by rotating rod and tail suspension. The brain injury was observed by naked eyes and TTC staining. In addition, we measured the inflammation ( Tnf-α, Il-6, and Mcp-1) and oxidative stress (Malondialdehyde (MDA) and T-AOC) in the injured tissue 72 h post-stroke. Low-dose testosterone supplementation improved the motion ability and decreased brain injury. It also decreased the inflammatory factors ( Tnf-α, Il-6, and Mcp-1), decreased MDA product, and increased T-AOC. High-dose testosterone supplementation not only reduced the motion ability and aggravated stroke injury, but also increased the inflammation, MDA level and decreased T-AOC level. In summary, supplementation of testosterone at normal levels in elderly mice can alleviate post-stroke injury by reducing inflammation and oxidative stress; however, excessive supplementation may cause unexpected injuries. This study has important implications for the application of testosterone replacement therapy.

Psychobiological risk factors for suicidal thoughts and behaviors in adolescence: a consideration of the role of puberty

Suicide is the second leading cause of death among adolescents. While clinicians and researchers have begun to recognize the importance of considering multidimensional factors in understanding risk for suicidal thoughts and behaviors (STBs) during this developmental period, the role of puberty has been largely ignored. In this review, we contend that the hormonal events that occur during puberty have significant effects on the organization and development of brain systems implicated in the regulation of social stressors, including amygdala, hippocampus, striatum, medial prefrontal cortex, orbitofrontal cortex, and anterior cingulate cortex. Guided by previous experimental work in adults, we also propose that the influence of pubertal hormones and social stressors on neural systems related to risk for STBs is especially critical to consider in adolescents with a neurobiological sensitivity to hormonal changes. Furthermore, facets of the pubertal transition, such as pubertal timing, warrant deeper investigation and may help us gain a more comprehensive understanding of sex differences in the neurobiological and psychosocial mechanisms underlying adolescent STBs. Ultimately, advancing our understanding of the pubertal processes that contribute to suicide risk will improve early detection and facilitate the development of more effective, sex-specific, psychiatric interventions for adolescents.