Fig. 1: Dendritic calcium signals are readily accessible from layer five neurons.
From: Dendritic calcium signals in rhesus macaque motor cortex drive an optical brain-computer interface
Two photon (2P) calcium imaging is currently capable of recording neural activity from the surface down to approximately 600 µm (green region), but photon scattering poses a challenge for imaging deeper. In this work, we demonstrate that it is possible to record neural activity of Layer 5 pyramidal neurons with cell bodies approximately 1500 µm below the surface (red arrows, inset) by imaging apical dendrites in superficial layers (purple), in addition to somatic signals from neurons located in layers 2/3 (blue cell bodies). Nissl stain image source: brainmaps.org.
