Custom setup & micro drive

The Challenge

To design and fabricate a setup which would permit studying the effects of body odors on social relationships between mice for a leading European research institute. The system was to allow recoding neuronal activity in the olfactive region, perform optogenetic stimulation, record the subjects’ activity in high quality video and frame rates and precisely synchronize all these activities.

Our Solution

The main challenge to the success of the whole project was the creation of a custom version of our maDrive which due to the particularly challenging recording location, needed to be modified to reduce weight, for use with tetrodes and with a different entry angle.

In order to develop this new design, we therefore initiated a rather delicate prototyping phaseduring which we created a detailed 3D model in SolidWorks. This allowed us to virtually evaluate different possible solutions, identify potential criticalities for each and progressively refine the design. Once a satisfactory concept was defined, we proceeded to create a physical PoC version of the drive using 3D printing to enable us to conduct a more realistic evaluation of key activities such as assembly and implantation. At each step in the process we reviewed the design with the researcher to ensure we were on the right track.

After a few iterations, during which we arrived at a model which satisfied both our own as well as the researcher’s requirements, we moved on to the development of the final design of the drive.

The result was an extremely light drive contoured in such a way as to easily reach the area of interest for recording, while maintaining the ability to adjust the height of electrodes after implantation.

In parallel, we developed the whole setup composed of the following items:

•  a mechanical structure, including contrast lit floor, supports for camera, optogenetics, distraction lighting and housing for data acquisition electronics boards with related cablingand connections
• an aoLED unit for optogenetic stimulation
• a distraction light for use in conjunction with optogenetics
• a neuronal recording system based on Open Ephys
• a customized version of the Open Ephys software which included control of optogenetic stimulation, distraction lighting, video recording and ability to record all information in a synchronized fashion
• a custom build controller board to enable the integration and control of all signals

 

The end result was a highly integrated and easy to use system in which all signals of interest are recorded in a synchronized manner.

At the time of writing, the setup has been operational for over two years without ever requiring maintenance or support, and over 50 maDrives have been delivered and successfully implanted.