This is an application in response to RFA-NS-17-00 4 ?BRAIN Initiative: Optimization of Transformative Technologies for Large Scale Recording and Modulation in the Nervous System (U01)?. In a proof-of-concept publication we demonstrated a novel fiber-coupled miniature microscope that achieved 3D confocal imaging of fluorescently labeled neurons in brain tissue using electrowetting lens technology for axial focusing. This low weight instrument (<2 g) is suitable for surgical implantation to achieve all optical awake behaving recording with axial focusing deep in the mouse brain, a significant advance compared to commercially available devices. In this proposal we present a major breakthrough demonstrating successful imaging through the fiber coupled microscope using two-photon microscopy. Leveraging on this result we propose to optimize our proof of concept E-FCM (electrowetting-fiber coupled microscope) by making it compatible for two-photon excitation (2PE-FCM) suitable for recording and modulating neural activity in awake behaving mice. Our 2PE-FCM will incorporate holographic two-photon opsin stimulation with a spatial light modulator (SLM) for rapid 3D volumetric two-photon imaging and modulation of neuronal activity. Optimization of the 2PE-FCM will be achieved by regular interactions of beta users with a multidisciplinary group of physicists, engineers and neuroscientists in a parallel process of design implementation and testing the device. Testing of the 2PE-FCM will employ a step-by-step approach designed for effective generation of a device suitable for studying local circuits in different brain areas in different species. We propose a solid dissemination plan partnering with Intelligent Imaging Innovations Inc. to commercialize the device. Validation of the 2PE-FCM will be a major advance in all-optical interrogation of neural circuits creating a new venue for understanding the neural basis of behavior.
Aim 1. TECHNICAL APPROACH: Optogenetic activation and simultaneous readout of deep brain neurons using a novel fiber coupled microscope with a variable focus electrowetting lens using no moving parts.
Aim 2. MILESTONES AND TIMELINE: Validate and disseminate the 2PE-FCM device for studies of the neural basis of behavior in freely behaving animals.
A current challenge for understanding brain function is selective deep brain control of neuronal firing in freely moving animals. We will develop and disseminate a novel two-photon miniature fiber coupled microscope (2PE-FCM) to allow flexible all optical interrogation of neural circuits. We will optimize the 2PE-FCM device by interaction with select beta users interested in key neural functions such as processing of sensory input, decision making, social communication, myelination and vocal learning. Optimization of this innovative device will allow novel studies of brain activity in health and disease.
| Ozbay, Baris N; Futia, Gregory L; Ma, Ming et al. (2018) Three dimensional two-photon brain imaging in freely moving mice using a miniature fiber coupled microscope with active axial-scanning. Sci Rep 8:8108 |
