Multiphoton imaging and control of opsins in living neural systems by spectral-temporal modulation of a supercontinuum source

Melanopsin is a recently discovered photopigment with a myriad of interesting properties. Found primarily in intrinsically photosensitive ganglion cells (ipRGCs), melanopsin absorbs light to trigger a cascade of intercellular events to activate ipRGCs. These cells then signal to various parts of the brain to regulate diverse functions. Most compellingly, these cells project to the suprachiasmatic nucleus (SCN) of our brain, and facilitate the regulation of circadian rhythms by integrating ambient light input. Intriguingly, there have been multiple studies that document the functional bistability, and potential tristability of melanopsin activation. That is, this photopigment has different activation kinetics based on the wavelengths of light that it absorbs, which theoretically furthers its ability to regulate circadian and other rhythms through assimilation of chromatic inputs. Despite the rich amount of functionality built into melanopsin from visible light absorption, no studies have been established to determine the effects of nonlinear optical processes on melanopsin activation. More specifically, no investigations have determined if two-photon absorption can be used to also elicit photoactivation of the photopigment. Despite advances in optical engineering for neural imaging, optical engineering efforts capable of interrogating such multispectral dynamics are lacking. Moreover, the conditions needed to elicit this response in melanopsin have not been established. This thesis shows advances in optical engineering and pulse-shaping that realize these biophysical phenomena. The engineering efforts in this thesis facilitated successful two-photon activation of melanopsin. I also show that the multistable properties of melanopsin can be interrogated both through modification of the chromatic, as well as the phase-structure of the incident laser pulses. The work presented in this thesis establishes the precedent for two-photon investigations of melanopsin, and consequently opens the doors for new research directions to investigate melanopsin systems with nonlinear optical technologies.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Bioengineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2024

Author dc:creator

• Renteria, Carlos A.

Contributors dc:contributor

• Boppart, Stephen A
• Gruebele, Martin
• Zhao, Yang
• Vlasov, Yuri

• Nonlinear Optics
• Two-photon Microscopy
• Retina
• Iprgcs
• Melanopsin
• Coherent Control
• Imaging

Statement dc:rights

• Copyright 2024 Carlos A. Renteria

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/125772

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F125772