A high-speed confocal laser-scanning microscope based on acousto-optic deflectors and a digital micromirror device

Neuronal dendrites are known to possess active computational properties. An ideal method of investigating these properties would be to monitor the complete electrical and chemical behavior of a single cell; however, currently available recording techniques force a tradeoff between spatial and temporal resolution. The objective of this project is to develop a confocal microscope that can make multisite optical recordings of single neuron function in a living brain slice at a frame rate sufficient to measure neuronal events that occur on a 1 ms timescale. Specifically, we would like to measure membrane potential and calcium concentration changes using voltage and ion-sensitive fluorescent indicators at user-selected sites-of-interest (SOIs). To accomplish this, we use acousto-optic deflectors (AODs) as random-access beam positioners in the illumination path, along with a digital micromirror device (DMD) as an addressable spatial filter in the detection path. We have demonstrated that our device is capable of optical sectioning and therefore capable of imaging in light-scattering preparations such as brain slices. Furthermore, our system is capable of an aggregate frame rate of up to 25 kHz.