Handling Penetrating Probes

Probe Handling

  • Some NeuroNexus probes can be quite delicate. We recommend extra caution when handling probes, and only handling them when necessary.
  • NeuroNexus penetrating probes may perform better with slower insertions than faster ones, due to tissue response. We recommend gradual probe advancement to the target region.

Basic Implantation Strategy

  1. Measure impedances to verify the sites are functional - a multichannel impedance system is useful for this purpose.
  2. For chronic experiments, sterilize the probe using Ethylene oxide (ETO). Soaking the probes in alcohol may also work.
  3. Prep the animal and open the craniotomy using your approved protocol. Remove dura.
  4. Using the stereotactic frame and the manipulator, slowly implant the probe and advance to the target region. If the probe buckles, DO NOT force insertion; wait 5-10 minutes. Typically the probe will slowly work its way into tissue.
  5. For chronic experiments, apply the first layer of barrier using agar. Build up a “dam” using gelfoam and completely fill and protect any unimplanted shank with silicone (such as Kwikseal from WPI). Close up the craniotomy using dental acrylic. Check impedance and compare with impedance data from step 1 to ensure that the probe was not damaged or broken during the implantation.

Care for your Penetrating Probes

  • Store probes in their shipping box. Keep the record that came with the probes. This will help you identify the probe designs in the future.
  • For Penetrating Probes/Packages, withdraw probe from tissue after the experiment and rinse with DI-water immediately. Soak probe (only the silicon shank and avoid the silicone coating) in a protein dissolving detergent/enzyme (such as contact lenses solution or diluted surgical instrument detergent). The process may take a few hours. Alcohol rinse is not recommended as it may dehydrate any residual tissue, causing protein to stick to the electrode site.
  • Use connector covers to protect the exposed connectors of the chronic packages.