Introduction

This system is a widely used tool to monitor the neuronal activity of behaving animals by recording the dynamic transient of weak fluorescence signals induced by type-specific neuron firing. The system adopts a bundle of multimode fiber to transmit excitation light and collect fluorescence signals. The average intensity of each fiber is calculated in real time to realize the simultaneous recording of multiple brain regions or animals.

Advantages

Three excitation channels: 470 nm and 560 nm can be used to excite two different fluorescent proteins, and 405 nm light is used as a reference channel to remove motion artifacts.

The number of channels depends on the number of fibers in the fiber bundle, making it easy to extend.

Four-port (up to eight-port) behavioral event acquisition, each port supports up to 1 kHz sampling rate.

Custom-designed acquisition program with options for short-term (continuous) or long-term (interval) recording.

System and Signal Example

Fig. (A) System picture. (B) An example of calcium signals.

Principle

The three excitation light sources are combined into one beam and coupled by the objective to the multimode fiber bundle. The multiple optical fibers then transmit the excitation light to different brain regions of the same mouse, or to different mice. The fluorescence signal is collected to the focal plane of the objective through the same multimode fiber and finally captured by the camera.

Parameters