Calcium Imaging Of Mouse Cortex And Its Application In Lever Movement

To understand such a complex system as brain,effective observation technologies are indispensable.For decades,extracellular electrophysiology has been the main means of recording brain signals.However,due to its inherent limitations,new methods for brain observation have devoloped quickly.Calcium imaging methods have overcome many limitations of electrophysiology.For example,calcium imaging can simultaneously record a larger number of neurons and ensure that the same cells are recorded over a long period of time.Therefore,with its outstanding advantages,the calcium imaging method has gradually become an effective tool and successfully recorded neuron activities in many animals.The goal of this project is to successfully record calcium images in motor cortex of mice,and use the calcium imaging as the signal source for the neural decoding paradigm of mouse lever-movement,instead of previous electrical signal.We performed three kinds of surgeries in a total of 49 mice.Two types of surgeries were successfully performed on two and three mice respctively.We trained 4 mice to press the lever,and recorded calcium images and animals bahaviors simultaneously.Every mouse performed 3tasks,and each task lasted for 12-20 minutes.The signal extraction algorithm of single photon imaging was used to process the vidoes,which includes three modules,the neural signal enhancement module,the movement correction and the neuron signal extraction module.Finally,the calcium signals’ dimensions were reduced by PCA and t-SNE.Then,the low-dimension signal samples were used as the input of the support vector machine to discriminate whether the mouse was pressing the lever.The results showed that the calcium signal of each mouse could successfully discriminate the lever movements,and the accuracies were all above 99%.