McNair Scholar 2017 - Nahom Mossazghi

Cranial Prostheses for Chronic, Pan-Cortical Two-Photon Imaging in Behaving Mice

Abstract: Chronic long term imagining of neurons has become increasingly important in recent years to understand and comprehend how information is encoded in the central nervous system at the single and population level.  There have been several technological strides made to help neuroscientist visualize spontaneous and stimulated neuron firing but have been limited to small regions of observation. To address the limitations current chronic cranial imaging window preparations, we have developed 3D printed morphologically realistic, transparent cranial prostheses that allow cellular resolution optical access to the entire dorsal cortex. We have validated the ability to implant these 3D printed cranial implants for long durations, and preliminary experiments indicate a capacity to perform 2P imaging in the chronically implanted Thy-GCaMP6f mouse and detect Ca2+ activity in individual neurons. Implanted mouse was trained in motorized disc treadmill, while simultaneously carrying out in vivo optical 2POI imaging. Future work includes extending 2POI to the whole dorsal cortex and histological analysis to assess the inflammatory response of chronic implantation. In addition, we plan to use this technology to study mesoscale and cellular scale activity of defined cell populations in an animal model. The tottering mice (tg/tg) are mouse model used to study Episodic Ataxia type 2, a disease caused by a mutation in the CACNA1A gene and exhibit several characteristics including transient motor ataxia which can be triggered by stress, caffeine, and alcohol.