Ultrafast pulse shaping modulates perceived visual brightness in living animals

Area of Science:

• Biophysics
• Neuroscience
• Quantum Optics

Background:

• Current understanding assumes vision sensitivity to light intensity and spectrum, not spectral phase.
• Previous experiments indicated ultrafast photoisomerization in retinal proteins is controllable by laser pulse phase.
• A direct link to biological vision processes remained unproven.

Purpose of the Study:

• To investigate if electrophysiological signals in living mouse retinas are sensitive to femtosecond laser pulse spectral phase manipulation.
• To explore the role of coherent control in the initial steps of vision.

Main Methods:

• Stimulation of living mouse retinas with femtosecond multipulse and single-pulse light.
• Measurement of resulting electrophysiological signals.
• Utilized dynamics simulations to support experimental findings.

Main Results:

• Retinal electrophysiological signaling demonstrated sensitivity to femtosecond timescale light excitation manipulation.
• Evidence suggests mechanisms like pump-dump and pump-repump processes near conical intersections are involved.
• Experimental and simulation data support the proposed mechanism.

Conclusions:

• The initial photoisomerization step in vision is sensitive to the spectral phase of light.
• Coherent control of light-matter interactions plays a role in biological vision.
• This study bridges in vitro findings with in vivo retinal signaling.