Population-wide place cell remapping after single cell stimulation in CA1

Abstract

The hippocampus is regarded as an important center for spatial mapping, primarily due to the discovery of CA1 pyramidal neurons whose activity is modulated by the position of an animal in an environment. These ensembles of place cells produce a neural representation of position in space and rapidly change their position preferences upon entry to a new environment in a process called remapping. Place field development is preceded by dendritic plateau potentials produced by conjunctive input from CA3 and the medial entorhinal cortex. Artificial place field induction via direct current injection has been shown to modify the activity of CA1 neurons. In this study, I investigate the role of place field induction of a single CA1 neuron in remapping the activity of nearby neurons. By conducting induction experiments in the mouse CA1 using simultaneous two photon imaging and two photon photostimulation of neurons, I was able to record the activity of hundreds of neurons at a time and execute precise stimulations while an animal traversed a virtual reality environment for liquid reward. Ultimately, this study finds that place field induction in targeted cells causes nearby cells to exhibit significant changes in place coding, particularly near the stimulation zone. Additionally, reward zone representational drift is also found following stimulation, though the causes of reward zone place field loss are uncertain.