MBExC Lecture

Francesco Gianoly, PhD, from the Hudspeth Laboratory of Sensory Neuroscience at the Rockefeller University and the Howard Hughes Medical Institute will held a talk about “Watts in My Ear? Local Critical Behavior as the Engine of Cochlear Amplification” during the MBExC Lecture on 11 December, 2025 at 12:00 p.m. at the lecture hall, MPI-NAT City Campus.

Abstract:
We are creatures of sensation, with hundreds of millions of photoreceptors, millions more for touch, smell, and taste. Yet, in each ear, only 16000 hair cells allow us to hear from a whisper to a thunderclap, operating at frequencies thousands of times those of vision. How do the ear’s sensory hair cells achieve this? They must be doing something different—and different by orders of magnitude.
Indeed, uniquely among our sensory organs, the ear expends energy to amplify the very stimuli that it detects. This so-called “active process” endows the cochlea with exceptional sensitivity, sharp frequency tuning, and broad dynamical range—yet its workings remain elusive. To date, the cochlea’s fragility and inaccessibility have confined studies in vivo, where global phenomena such as traveling waves confound the local cellular dynamics.
To overcome this hurdle, we developed a new bio-chamber that preserves the active process ex vivo in an isolated segment of the cochlea by recreating its physiological environment. With it, we showed: First, that the active process is not an emergent property of the entire organ, but it can manifest within a local patch of about 200 sensory receptors in the absence of traveling waves. Second, that the sensory tissue operates on the verge of a Hopf-type state of criticality, a regime at the edge of order and chaos where sensory responses are enhanced.
Comparable critical dynamics had been demonstrated in amphibians, birds, and insects, yet their presence in mammals remained disputed. By revealing the same regime in the mammalian cochlea, our work points to a conserved evolutionary solution to the problem of detecting and encoding signals with high sensitivity and selectivity, in which criticality functions as a unifying biophysical principle of sensory processing.

Host: Prof. Dr. Tobias Moser, UMG

Poster of the talk: