We recently found that the newt brain actively produces 7α-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 7α-hydroxypregnenolone, we investigated seasonal changes in 7α-hydroxypregnenolone synthesis in the brain of male newts. Interestingly, 7α-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 7α-hydroxypregnenolone induces seasonal locomotor changes in male newts.