Sensitive periods and brain plasticity
Sensitive periods are developmental phases in which the nervous system is most easily modified by experience. Using rodent models, our research is aimed at (1) identifying sensitive periods of enhanced neuroplasticity and modification by steroid hormones (2) determining the brain and behavioral impacts of steroid hormone exposure during sensitive periods, and (3) determining the neural mechanisms regulating the timing of sensitive periods for steroid-dependent brain and behavioral development.
PUBERTAL TIMING during adolescence
Pubertal timing varies widely between individuals, and whether individuals undergo pubertal development early or late relative to their peers increases risk for mental illness. In general, late maturing boys and early maturing girls are at greatest increased risk for psychopathologies such as depression, disordered eating, substance abuse, and disruptive behavioral disorder. Scientific explanations of the relationship between pubertal timing and mental illness have primarily focused on the social and emotional consequences of off-time pubertal development relative to one’s peers in boys and girls. However, pubertal gonadal steroid hormones also alter the trajectory of brain development during adolescence. Using rodent models, we are investigating whether the timing of exposure to gonadal steroid hormones during adolescence impacts social, cognitive and emotional behavioral outcomes in adulthood. In addition, we are investigating whether extracellular matrix structures termed perineuronal nets regulate the timing of adolescent sensitivity to gonadal steroid hormones.
developmental stress
The prenatal period and adolescence are two phases of development consistently linked with adult psychiatric illness. For example, when a woman experiences extreme stress during pregnancy, her offspring have an increased risk for psychiatric problems such as anxiety, depression, and schizophrenia. In contrast, adolescence is the time when many stress-related psychiatric illnesses tend to emerge. We are currently investigating the impacts of adolescent stress on cognitive and emotional development, and whether brain immune responses mediate the relationship between adolescent stress and impaired cognitive function.