Optical recording with single cell resolution from monolayered slice cultures of rat hippocampus.

Voltage-sensitive dyes were used to optically record the membrane potentials from neurons in hippocampal slice cultures. Multi-channel recordings from these monolayered but otherwise 'organotypic' slice cultures had very good spatial as well as good temporal resolution (15 x 15 micron, 0.5 ms respectively). We show that in this preparation action potentials elicited by intracellular current pulses can be recorded optically and that single spikes are readily detectable without averaging. Furthermore, a new procedure which significantly reduces photodynamic damage is described. Our study demonstrates the feasibility of optical recording with single cell resolution in an organotypic mammalian CNS preparation.