Seasonal Changes in the Synthesis of the Neurosteroid 7α‐Hydroxypregnenolone Stimulating Locomotor Activity in Newts

Abstract

We recently found that the newt brain actively produces 7alpha-hydroxypregnenolone, a novel amphibian neurosteroid stimulating locomotor activity. It is well known that locomotor activity of male newts increases during the breeding period. To understand the physiological role of 7alpha-hydroxypregnenolone, we investigated seasonal changes in 7alpha-hydroxypregnenolone synthesis in the brain of male newts. Interestingly, 7alpha-hydroxypregnenolone synthesis in the brain showed marked changes during the annual breeding cycle, with a maximal level in the breeding period when locomotor activity of male newts increases. These results suggest that 7alpha-hydroxypregnenolone induces seasonal locomotor changes in male newts.