Imaging Neural Circuits in Absence Epilepsy Using Miniaturized Microscopes

Epilepsy is the fourth most common neurological disorder that is caused by an abnormal and sudden rush of electrical activity in the brain. It is characterized by unpredictable seizures with different types and intensities, such as generalized seizures, which affect the entire brain, and focal seizures, which affect just one part of the brain. Such seizures arise due to complex interactions between different neural circuits throughout various regions in the brain. This research project aims to better understand the function of the thalamus in amplifying the excitatory stimulation that occurs during a seizure, which can prolong the duration of electrical activity within a region of the brain during a seizure. By using GCaMP, a green fluorescent protein that fluoresces brighter when neurons fire, a miniature fluorescence microscope (MiniScope) will be used to record neuronal activity in awake, freely moving mice. The MiniScope will be inserted above a mouse’s thalamus to observe neurons firing at different times and sites during a seizure. Using a living animal that will undergo epileptic seizures will enable the visualization of neurons firing within an intact brain, as opposed to viewing neurons in a brain slice from an animal that has been sacrificed, which does not allow for as much information about the thalamus’ role in seizures. By utilizing the MiniScope, this research allows for an in vivo method to record neuronal activity, leading to a better understanding of the thalamus’ importance in epileptic seizures.