Characterization of hippocampal CA1 place cells.

Abstract

Hippocampal place cells play a role in learning and memory, and spatial navigation. Previous studies have shown the presence of place cells in the hippocampus and their characteristics. As part of a project of a PhD student, Mr. Mehdi Fallahnezhad, this research was conducted on rats’ hippocampus CA1 pyramidal cell layer and required the rats to carry out spatial explorations of both familiar and novel environments. A familiar environment was the arena the rat was first introduced to explore prior to surgery. Each exploration session was for ten minutes. Activity of neuronal cells was recorded using a microdrive, mounted with four tetrodes. Nine principal cells were visually identified, showing place cell-like characteristics, such as remapping when introduced into a novel environment, and stability of spatial-specific firing in a familiar environment after remapping has occurred due to exposure to a novel environment. This suggests the importance of the hippocampal place cells in the process of learning and converting the information to long-term memory. The result of this study could provide a basis or serve as a control for further studies.