Multi-Unit-Activity

The Multi-Unit-Activity Filter (MUA) is a single channel filter amplifier module with a built in high accuracy rectifier for selection of multiple unit activity of groups of neurons from broadband extracellular recording. It is designed as a plug-in unit for use with the 19′′ rackmountable cabinet, also manufactured by Thomas Recording. Up to 8 single channel modules can be mounted to one 19 rackmountable
cabinet.

The MUA-Filter includes a low-noise differential amplifier with adjustable amplification, a low-pass filter with adjustable cut-off frequency, a high-pass filter with adjustable cut-off frequency and a high accuracy rectifier with following internally adjustable low-pass-filter.

After amplification and band-pass-filtering, the signal is rectified and afterwards again low-pass-filtered in order to reveal an evelope signal proportional to the strength of the multi-unit-activity.