Two-photon imaging of dendritic calcium dynamics in vivo

Abstract

Developments in microscopes and indicators over the past decade have paved the way for recording neural dynamics in vivo. Previously inaccessible small neuronal processes, such as dendrites and axons, can now be probed in vivo using two-photon microscopy, revealing their important role in information processing during behaviour. To perform such experiments, various tools, techniques and considerations are required. In this chapter, the procedures for recording dendritic calcium dynamics in vivo are detailed in a step-by-step manner. The various sources of calcium contributing to the recorded transients are discussed, and details are given on how to identify them from the characteristics of the recorded fluorescence transients. These procedural details and considerations regarding two-photon calcium imaging of dendritic activity are put in context of the importance of such recordings for understanding neural function during behaviour.