Automated Multichannel Bidirectional Fiber Optic Rotary Device for Brain-Behavior Studies

The project proposed herein addresses an urgent need for approaches that allow minimally invasive long term optical recording deep in a mouse brain with high spatial and high temporal resolutionUnderstanding the causal relationship between brain neural activity and behavior is among the research priorities of NIAAA and one of the main objectives of the BRAIN initiativeA lot of progress has been made to optically perturb and monitor neural circuit dynamics during behaviorHoweverthe practical implementation is still largely limited to one location in the brain at a timeand there is still an urgent need for simultaneous minimally invasive long time optical recording deep in the brain at multiple sites with spatial and temporal resolutionSimultaneous recordings at multiple sites will allow neuroscientists to gain new insights by constructing a global view on the timing and synchrony of biochemical signals among neuronsprojectionsand different brain regionsThey shed light on neural mechanisms underlying normal behavior and behavior associated with alcohol addictiondrug addictionParkinson s diseaseand other neuromuscular and neuropsychiatric diseases in freely moving rodentsThe proposed project aims to design an automated multichannel bidirectional FORJ that will allow the simultaneous transfer of optical signals to and from multiple sites of the brain through a rotating interface and with minimal mechanical impact on the natural behavior in a freely moving mouseThe first aim is to build a two channel bidirectional FORJ prototype deviceThe design principlein a nutshellis to dynamically measureusing an angle encoderthe movement of a mouse and automatically release the torsion in the optical cable by engaging a brushless DC motor to unwind the twisted optical fiber by n number ofturnsTo optimize its efficiencythe unwinding process is activated automatically only when the angle encoder reaches an experimentally determined thresholdThe second aim is to perform tests to validate and quantitatively characterize overall light throughputtransmission variation over rotationstarting torqueand synchronization of the FORJ with data acquisitionFinallyon the basis of the two channel FORJa four channel FORJ will be built by extending the channel capacityThe project proposed in this application takes a unique approach by combining optical design and rotational sensing to reduce the optical design complexity and reduce the number of mechanical moving parts in order to improve signal to noise ratioThe multichannel bidirectional FORJ potentially offers the alcohol addiction research community expanded capability to investigate ethanol effects on learning and decision makingMore broadlyit offers the neuroscience community the possibilities to investigate the causal relationship between dynamic biochemical activity of neuronal circuits and behavior across spatial and temporal scales PROJECT NARRATIVE An automated multichannel bidirectional fiber optic rotary joint is a critical optical device that allows optical signals to be simultaneously transferred through a rotating interface to and from multiple sites deep in the brain of a rodentand with minimal mechanical impact on the natural behavior in a freely moving rodentIt makes it possible to investigate the biochemical signaling pathways in the brain that control normal behavior and behavior as related to alcohol or drug addiction and their effects on learning and decision makingFurthermorethe same device will find a broad range of applications in studies related to other neurological and neuropsychiatric diseases!