Functional Assessment of Melanopsin-Driven Light Responses in the Mouse: Multielectrode Array Recordings

Area of Science:

• Neuroscience
• Vision Science
• Retinal Physiology

Background:

• Intrinsically photosensitive retinal ganglion cells (ipRGCs) utilize melanopsin for light detection, crucial for non-image-forming (NIF) visual functions.
• Studying ipRGCs is challenging due to their small proportion within retinal ganglion cells.
• Melanopsin-driven responses are vital for various physiological processes, including circadian rhythms and pupillary light reflex.

Purpose of the Study:

• To detail a multielectrode array (MEA) recording technique for studying melanopsin-driven light responses in mouse retinas.
• To provide a methodological framework for researchers investigating ipRGC function.
• To enable high-throughput functional assessments of ipRGCs and NIF vision.

Main Methods:

• Utilizing multielectrode array (MEA) recording for noninvasive, simultaneous monitoring of multiple ipRGCs.
• Silencing rod/cone photoreceptor synaptic input using glutamatergic blockers.
• Recording extracellular electrical signals from ipRGCs activated by melanopsin.

Main Results:

• Demonstrated the feasibility of MEA recording for capturing melanopsin-driven signals from ipRGCs.
• Established a standardized procedure for MEA recordings in adult mouse retinas.
• Provided a list of necessary instruments, tools, and reagents for successful MEA experiments.

Conclusions:

• MEA recording offers a powerful paradigm for functional assessment of ipRGCs.
• This technique facilitates the study of melanopsin-driven light responses and NIF vision.
• The described methodology can advance research in retinal physiology and visual neuroscience.