Gray Matter Research

Type: Electrophysiology / Probes,

Keywords: Microdrive systems, Electrophysiology, Neural circuit activity, Non-human primate

Distributed recording systems for measuring neural circuit activity

Gray Matter Research designs and manufactures large-scale microdrive systems to enable semi-chronic recording of neural activity from large numbers of independently moveable microelectrodes to record neural circuit activity in behaving non-human primates. Recent innovations include a larger number of electrodes and longer travel distances, flexibility to curve electrode trajectories, ability to register the electrodes to post-op scans and improved reliability. Our microdrive systems are used in over 50 laboratories worldwide. We also developed a prosthetic instrument expanding the scope and reliability of a new generation of microdrives using multi-channel laminar probes. This class of instrumentation is under development and in use in multiple laboratories. These tools provide unprecedented capabilties for reseachers to measure the activity in distributed neural circuits in behaving non-human primate performing cognitive tasks.

* Gray Matter Research microdrives are modular, replaceable micromanipulator systems capable of independent bidirectional control of up to 256 individual microelectrodes.
* The systems are designed to be semi-chronically implanted with configurations that are tailored to the experimental questions.
* Electrode positions are independently controlled with high resolution and travel distances up to 42 mm.
* Electrical contact with the electrodes is achieved through a printed circuit board, which avoids the use of wires.
* The system can be implanted for months or years at a time to permit long-term recordings of neuronal activity with minimal daily setup time.

* The instruments can be used to measure the activity in neural circuits spanning the depth and breadth of the brain.

* Measuring the activity patterns within and among multiple cortical and subcortical areas during cognitive tasks.
* Enable microstimulation to assess the effects on behavior and neural circuit connectivity.
* Inclusion of instruments to manipulate neural circuit activity pharmacologically and optogenetically.

Non-human primates

* Significantly expand the scope, duration, and reliabiity of measuring neural circuit activity.
* Microdrives and associated components are fully assembled and sterilized before shipping and ready for implantation upon delivery.
* Enable the collection of vast quantities of data while improving the care of the animals and reducing the number of animals used for a given experiment.

* Localization of recording locations during an experiment is limited by the resolution of CT and MRI imaging.

* Designs are optimal when guided by pre-op MRI and CT scans.


Baldwin Goodell, Owner of Gray Matter Research


Gray Matter Research



Charles M. Gray



NIH U01NS090557
NIH R43NS102075