Binge-Pattern Alcohol Exposure during Puberty Induces Long-Term Changes in HPA Axis Reactivity

Adolescence is a dynamic and important period of brain development however, little is known about the long-term neurobiological consequences of alcohol consumption during puberty. Our previous studies showed that binge-pattern ethanol (EtOH) treatment during pubertal development negatively dysregulated the responsiveness of the hypothalamo-pituitary-adrenal (HPA) axis, as manifested by alterations in corticotrophin-releasing hormone (CRH), arginine vasopressin (AVP), and corticosterone (CORT) during this time period. Thus, the primary goal of this study was to determine whether these observed changes in important central regulators of the stress response were permanent or transient. In this study, juvenile male Wistar rats were treated with a binge-pattern EtOH treatment paradigm or saline alone for 8 days. The animals were left undisturbed until adulthood when they received a second round of treatments consisting of saline alone, a single dose of EtOH, or a second binge-pattern treatment paradigm. The results showed that pubertal binge-pattern EtOH exposure induced striking long-lasting alterations of many HPA axis parameters. Overall, our data provide strong evidence that binge-pattern EtOH exposure during pubertal maturation has long-term detrimental effects for the healthy development of the HPA axis

The membrane actions of estrogens can potentiate their lordosis behavior-facilitating genomic actions

The membrane actions of estrogens can facilitate their genomic actions. To determine whether this facilitation bears on CNS mechanisms for estrogen-dependent behaviors, ovariectomized rats were subjected to a two-pulse treatment of estrogen directly in the hypothalamic ventromedial nucleus. Two days later, each rat was given progesterone and then tested for lordosis behavior, the induction of which requires the genomic actions of estrogen. When estrogen was given in both pulses (15 min to 2 h duration, and 5 h apart) lordosis was induced. Based on results from studies on neuroblastoma cells, we hypothesized that the membrane actions of estrogen in the first pulse would potentiate the genomic actions of estrogen in the second. This hypothesis was confirmed with the use of a membrane-impermeable estrogen. However, surprisingly, the order of the pulses could be reversed and still achieve lordosis behavior induction. Finally, activators of protein kinase A or PKC were effective substitutes for the membrane-limited pulse of estrogen. Thus, estrogen-induced membrane actions in the hypothalamus can potentiate its lordosis-inducing genomic actions on behavior and may be mediated by signaling pathways involving the activation of protein kinase A and PKC