How do mice perceive sounds? - briefly
Mice detect acoustic signals via a highly sensitive auditory system that includes a cochlea tuned to «ultrasonic frequencies» and specialized hair cells converting vibrations into neural impulses.
How do mice perceive sounds? - in detail
Mice detect acoustic signals through a peripheral system specialized for high‑frequency hearing. Sound waves enter the external auditory canal, vibrate the tympanic membrane, and are transmitted by the ossicular chain (malleus, incus, stapes) to the oval window of the cochlea. Within the cochlear duct, the basilar membrane exhibits a tonotopic arrangement: the basal region responds to frequencies above 30 kHz, while the apical region processes lower frequencies down to 1 kHz. Mechanical displacement of the basilar membrane deflects stereocilia on inner‑hair cells, converting mechanical energy into receptor potentials via mechanotransduction channels. Inner‑hair cells synapse onto afferent auditory nerve fibers, which encode stimulus intensity and temporal patterns through spike rate and phase locking.
Processing of auditory information proceeds through the brainstem nuclei:
- Cochlear nucleus (dorsal and ventral divisions) extracts spectral and temporal features.
- Superior olivary complex computes interaural time and level differences, supporting sound localization.
- Lateral lemniscus conveys processed signals to the inferior colliculus, where integration of frequency and spatial cues occurs.
- Auditory thalamus (medial geniculate body) relays information to the auditory cortex, enabling discrimination of complex sounds and learning of vocalizations.
Behavioral studies reveal that mice exhibit acute sensitivity to ultrasonic vocalizations (USVs) produced during social interactions. Detection thresholds reach 10 dB SPL for frequencies around 70 kHz. Conditioning paradigms (e.g., tone‑avoidance, startle reflex) demonstrate rapid learning of sound–stimulus associations, reflecting plasticity in cortical and subcortical circuits.
Electrophysiological techniques such as auditory brainstem responses (ABR) and in vivo calcium imaging provide quantitative measures of auditory thresholds, latency, and neural population dynamics. Genetic manipulation (knock‑out or over‑expression of ion channel genes) alters hair‑cell function and frequency tuning, confirming molecular contributors to auditory perception.
In summary, mouse auditory perception relies on a finely tuned peripheral apparatus, a hierarchical central processing network, and adaptive behavioral responses to high‑frequency acoustic cues.