Seasonal Sex, Neurotransmitters, and the Turkey Brain

Okay, I couldn’t resist. Today is the Thanksgiving holiday in the United States so I decided to discuss a paper that deals with the turkey brain. Specifically, this is a recent paper is on seasonal sex, neurotransmitters, and the turkey brain.

What triggers female turkey seasonal sexuality? The brain-based mechanisms responsible for the timing and induction of female turkey seasonal sexuality have been unknown. A specific set of neurotransmitters in the brainstem and midbrain (serotonin, dopamine, norepinephrine, and epinephrine) are known important regulators of reproductive function in the female turkey. It’s also been shown that neurons in a particular part of the turkey brain, the premamillary nucleus, contain both dopamine and melatonin and are active while the turkey is exposed to light. The authors of a recent paper hypothesized that these brainstem neurons may interact with the premamillary nucleus to form a brain circuit for regulating seasonal sex in turkeys.

The paper “Serotonergic and Catecholaminergic Interactions with Co-Localised Dopamine-Melatonin Neurones in the Hypothalamus of the Female Turkey” was published January 2009 in the Journal of Neuroendocrinology.

The team’s finding suggest that indeed brainstem and midbrain modulatory neurotransmitters influence the dopamine and melatonin containing neurons in the turkey premamillary nucleus. These interactions affect how the system reacts to light (as the days get longer in the spring). This newly described brain circuitry opens a previously shut door on the mechanisms regulating seasonal sex in female turkeys.