A compact, modular two-photon fiber-coupled microscope for in vivo all-optical electrophysiology

Good methods to interrogateand ideally perturbneural systems at the network level have been elusive until recentlyThe advent of biochemical breakthroughsnamely neuronally targeted genetically encoded calcium reporterssuch as GCaMPand light activated channelssuch as channelrhodopsinhave enabledall opticalelectrophysiology where experiments can be conducted that involve simultaneousor closely sequencedstimulation of multiple neurons and readout of an entire field of cortical or subcortical tissueIntelligent Imaging InnovationsIncihas developed computer generated holographyin conjunction with the laboratory of Dr Valentina Emiliani at Paris Descartes UniversitysinceThe collaboration has been a successi has since distributed overholography systems to research laboratories in North America and Europewhich have already produced multiple publicationswith more in preparation and reviewRecentlyi has also started working with the laboratories of Drs Emily Gibson and Diego Restrepo at the University of Colorado Anschutz Medical Campus to evaluate the feasibility of providing a commercial source for a novel two photon fiber coupled microscope that incorporates an electrowetting lens for remote focusingDrs Gibson and Restrepo are advancing the fundamental photonics researchpartially supported by the BRAIN UControlled neuronal firing in vivo using two photon spatially shaped optogeneticsDr Emilianiand her collaboratorDr Serge Picaudcontinue to advance computer generated holography with support from the BRAIN UThree Dimensional Holography for Parallel Multi target Optogenetic Circuit Manipulationand other fundingPreliminary resultsdescribed in this applicationsuggest thati can couple its multiphoton holography through the fiberscope in addition to performing scanning multiphoton microscopyallowing neuroscientists to stimulate individual neurons at multiple layers of cortex and monitor activity of a substantial field in freely moving animali proposes to assess the feasibility of developing a compactmodular turn key system for in vivo all optical electrophysiologyThe system would incorporate the necessary pulse compressionscanning pathwaydetection pathwaycomputer generated holographyand control softwareWe believe a commercial solution which incorporates the many collective years of expertise ofi and its collaborators in the fields of multiphoton imagingcomputer generated holographyand fiber coupled microscope design and assembly will enable many more laboratoriesparticularly those without extensive optical engineering resourcesto advance brain understanding faster and fulfill one of the BRAIN Initiative directiveswhich is to provide wide dissemination of the technologies developed under the initiativeIn order to provide such a solutionhoweveri must engage in further research and development to translate the benchtop results of Dr Gibson and Restrepo s laboratories into a candidate for commercialization Studies of animal models of normal and abnormal mental processes particularly those involving complex tasks are ideally performed with freely moving subjectsHoweveruntil recently technical impediments have prevented the recording and altering of the activity of many neuronswill cellular resolutionwithout physical restraint of the animal s headA two photon fiber coupled microscope that can transmit sculpted light to optogenetically targeted brain areasas well as record geneticallyencoded calcium indicator signals from the sameor even differentareaswill greatly increase the types of experiments that can be conducted where the animal is able to more fully interact with its environmentincluding social environments that include other animals similarly equipped