The use of macroelectrodes in recording cellular spiking activity

Microelectrode recording (MER) is an important navigational and investigational tool, specifically with regard to deep brain stimulation (DBS) surgery. MER is often utilized when targeting the subthalamic nucleus (STN) and other deep brain nuclei in the management of Parkinson's disease (PD), tremor, dystonia and other emerging applications. Microelectrodes are used to detect and measure cellular spiking activity while macroelectrodes are considered more suitable for measuring the collective sum of slow potentials from multiple cells near the electrode, the local field potential (LFP). Precisely how the characteristics of an electrode affect the data recorded is still unclear. Technical idiosyncrasies of some surgical cases allowed serendipitous data collection from a 250 to 6000 Hz bandpassed macroelectrode recording during DBS implantation for PD. Simultaneous recording from both a microelectrode and macroelectrode were compared along the same surgical trajectory. Audio, normalized root mean square of the recorded signal, and power spectrograms were used to analyze the data. The analyses demonstrate similar results in detecting cellular spiking activity when recording with macroelectrodes compared with microelectrodes. This has important implications for the standardization of recording electrophysiological data as well as for the development of next generation closed-loop deep brain stimulation systems.