Acoustically evoked potentials in two cephalopods inferred using the auditory brainstem response (ABR) approach

Area of Science:

• Marine biology
• Bioacoustics
• Neuroscience

Background:

• The auditory capabilities of cephalopods, particularly at higher frequencies, remain largely unconfirmed.
• Previous research has not provided definitive physiological evidence for sound detection above 400 Hz in these marine invertebrates.

Purpose of the Study:

• To investigate and confirm the sound detection abilities of cephalopods at frequencies exceeding 400 Hz.
• To resolve the ongoing debate regarding high-frequency sound perception in species such as Sepiotheutis lessoniana and Octopus vulgaris.

Main Methods:

• The study employed the auditory brainstem response (ABR) technique, a validated physiological method for assessing auditory function.
• ABR was applied to Sepiotheutis lessoniana and Octopus vulgaris to measure neural responses to sound stimuli.

Main Results:

• Auditory evoked potentials were successfully recorded in Sepiotheutis lessoniana within the 400 to 1500 Hz range.
• Auditory evoked potentials were also obtained in Octopus vulgaris between 400 and 1000 Hz.
• Detection thresholds for Sepiotheutis lessoniana were generally lower compared to Octopus vulgaris.

Conclusions:

• This research provides the first physiological evidence that cephalopods can detect underwater sound frequencies above 400 Hz.
• The findings demonstrate frequency-specific auditory evoked potentials in both studied cephalopod species.
• The study confirms a higher auditory sensitivity in Sepiotheutis lessoniana compared to Octopus vulgaris within the tested frequency range.