Steroid hormones play a critical role in the initiation and maintenance of pregnancy. In particular, the important role that the
progesterone metabolite, and
neurosteroid,
allopregnanolone, may play in fetal and adolescent development is becoming increasingly evident. Unlike
steroid hormones,
neurosteroids act at nontraditional targets in the central and peripheral nervous systems, including
GABA(A) receptor complexes. This commentary discusses the three works in this issue that elucidate the important role of
allopregnanolone in the mechanisms that regulate stress hypo-sensitivity of rodents in late pregnancy,
neuroprotective effects in fetal sheep exposed to a hypoxic insult, and the continuing role that prefrontal cortex formation of
allopregnanolone may play on the cognitive development of gestationally stressed rat offspring, grown to adolescence. The narrative that these works comprise was facilitated by the 5(th) International Meeting on
Steroids and the Nervous System (Torino, Italy), which is organized to update our knowledge on the relationships between
steroid hormones synthesized in different organs and the nervous system. Topics covered in this most recent meeting included sex differences in, and hormonal influences on,
cannabinoid-regulated biology;
steroids and
pain; the importance of co-regulatory factors for
steroid receptor action in the brain; mechanism and role of
estrogen-induced nonclassical signaling in the brain;
vitamin D as the forgotten
neurosteroid;
neurosteroids and
GABA(A) receptors; and pathogenic mechanisms mediated by
glucocorticoid receptors in
psychiatric disorders. The 6(th) International Meeting on
Steroids and the Nervous System will be held in Torino, Italy in February 2011.