Cyclic Regulation of Sensory Perception by a Female Hormone Alters Behavior

Area of Science:

• Neuroscience
• Sensory Biology
• Animal Behavior

Background:

• Female reproductive state influences behavior, mediated by hormones acting on the brain.
• The impact of the ovulation cycle on sensory processing, particularly pheromone detection, remains largely unexplored.

Purpose of the Study:

• To investigate whether incoming sensory activity in female mice differs across the ovulation cycle.
• To determine if the estrous cycle modulates the detection of male-emitted pheromones by vomeronasal sensory neurons (VSNs).

Main Methods:

• Electrophysiological recordings from VSNs in female mice across different stages of the estrous cycle.
• Pharmacological manipulation to assess the role of progesterone in VSN silencing.
• Identification of signaling pathways involved in progesterone-mediated VSN inactivation.

Main Results:

• VSNs in female mice are selectively "blind" to specific male pheromone ligands during diestrus but responsive during estrus.
• Progesterone, a key female sex steroid, mediates this temporary VSN silencing.
• VSNs detecting non-pheromone ligands, such as those from cats, remain active regardless of the estrous cycle stage.

Conclusions:

• Internal physiological states, specifically the estrous cycle, can dynamically modulate sensory input.
• Progesterone selectively targets and inactivates specific subsets of pheromone-responsive VSNs, demonstrating a direct link between physiology and sensory processing.
• This selective sensory gating allows for state-specific behavioral responses in female mice.