Reproductive state modulates utricular auditory sensitivity in a vocal fish.

Area of Science:

• Neuroscience
• Animal Behavior
• Sensory Biology

Background:

• Plainfin midshipman fish use acoustic communication for reproduction.
• The saccule enhances auditory sensitivity, but the utricle's role is debated.
• The utricle may aid in detecting important sounds.

Purpose of the Study:

• To investigate if reproductive state affects the utricle's auditory sensitivity in female midshipman.
• To test the hypothesis that the utricle plays an auditory role in mate detection.

Main Methods:

• Recorded auditory-evoked potentials from utricular hair cells in reproductive and nonreproductive female midshipman.
• Measured responses to underwater sound across various frequencies.

Main Results:

• Reproductive females showed a sixfold increase in utricular potential magnitude.
• Utricular thresholds were 7-10 dB lower in reproductive females for particle acceleration.
• Enhanced sensitivity occurred across frequencies relevant to male calls.

Conclusions:

• The utricle has a seasonally plastic auditory function modulated by reproductive state.
• Enhanced utricular sensitivity aids in detecting male advertisement calls.
• This auditory role is crucial for midshipman social and reproductive communication.