Adapting a Two-Photon Scanning Microscope for Simultaneous Single-Photon Imaging of an Infrared Dopamine Sensor
Year: 2026
Type: article
Abstract: ABSTRACT We describe a novel method for adapting a two-photon scanning microscope to enable simultaneous detection of two-photon generated visible fluorescence and single-photon generated near-infrared (nIR) fluorescence. In this configuration, nIR fluorescence is routed through a single-mode optical fiber before detection by a photomultiplier tube. This fiber coupling offers two advantages: first, the optical fiber functions as a pinhole aperture, allowing for improved optical sectioning of the nIR signal; second, it minimizes nIR background fluorescence. To validate the effectiveness of this design, we conducted two sets of experiments. First, we compare two fluorescence indicators of the neurotransmitter dopamine: the genetically encoded indicator GRAB DA and single walled carbon nanotube based optical nanosensors (nIRCats). Although nIRCats exhibit lower affinity for dopamine than GRAB DA , this property allows for identification of high concentration release sites in the striatum. Second, we simultaneously imaged depolarization-induced calcium changes and dopamine release in the retina. Together, these results demonstrate the utility of integrating confocal nIR detection into a two-photon platform for simultaneous functional imaging across complementary spectral channels.
Source: eNeuro
Authors: Matthew Tarchick, Franklin Caval-Holme, Ben Smith, Petra Mocellin, Markita Landry, Natsumi Komatsu, Marla B. Feller
Language: English
Subfield: Biophysics
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $2,925
Awards: G6671297155, CAREER: Nanoparticle-mediated genome engineering of plants and plastids, G9000010938, Development of direction selectivity in retina, Transformations of photic information in melanopsin pathways, UC Berkeley Vision Science CORE, The Function of Neural Activity in Developing Retina
OpenAlex ID: W7154734577