مطالعه روشهاي كدگذاري عصبي در قشر بشكه‌اي مغز موش با استفاده از روش تصويربرداري كلسيم

چكيده انگليسي :

Study of Neural Coding Methods in Mice sBarrel Brain Cortex Using Calcium Imaging Mohammad Reza Salehi mohammadreza salehi@ec iut ac ir May 11 2019 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisors Assoc Profs Rasoul Amirfattahi fattahi@cc iut ac ir Mohammad Reza Ahmadzadeh Ahmadzadeh@cc iut ac ir Abstract The simple tasks that a person performs throughout the day is controlled by the relationship between a large numberof neurons in different regions of the brain therefore a complete interpretation of the functioning mechanisms in the brainneed simultaneously records many activities of the brain with the cellular resolution However current electrophysiologicalmethods for recording electrical signals of neurons such as electrode arrays do not have this capability and can only includea small subset of neurons One challenge in neuroscience studies is the comprehensive measurement of neuronal activityin humans or animals One ways to overcome this problem is two photon calcium imaging technique that can capture alarge number of neurons with cellular resolution However the main drawbacks of this technique are the imaging framerate which is slower than of firing rate of the neuronal cells and low signal to noise ratio Because of its invasivenesstwo photon calcium imaging it does not use for humans so for studying with this method we used animals with thebrain like structure of a human brain for example mouse As recent advances in calcium sensing technologies facilitatesimultaneously imaging action potentials in neuronal populations complementary analytical tools must also be developed tomaximize the utility of this experimental paradigm therefore because of nonlinear relation between calcium imaging dataand spiking data providing a model for neural encoding seems necessary In this research we present a generative modelincluding nonlinear functions linear filter spiking model and calcium kinetics model as evolution function and a model fortransform the calcium kinetics to the fluorescence trace as observation function to encode calcium imaging data Also dueto the spike frequency adaptation that can cause neural coding failure we use Morris Lecar model with adaptation currentsfor spiking model In order to estimate the parameters of the generative model we use VB Laplace method Finally theencoding model used for encoding the angle and curvature of mouse whisker in the barrel cortex during a pole localizationtask that result 42 of barrel cortex neurons encoding mouse whisker data Because a large part of the brain s activityis thought to be internally generated and hence quantifying stimulus response relationships alone does not fully describebrain dynamics therefore in this research we use extended transfer entropy for extraction of neuronal connections We willtry to improve the presented neural encoding model by use the three neurons with more connection The results indicate abetter estimate of the spike rate of barrel cortex neurons in the calcium imaging data Key Words Calcium Imaging Generative Model Spike Frequency Adaptation Transfer Entropy

صالحي نجف ابادي‌، محمئرضا

مطالعه روشهاي كدگذاري عصبي در قشر بشكه‌اي مغز موش با استفاده از روش تصويربرداري كلسيم

تصويربرداري كلسيم , مدل مولد , وفق پذيري فركانسي , آنتروپي انتقالي