Guidelines for Non-human Primate Neuroscience Studies

The IACUC has established the following guidelines for non-human primate neuroscience studies at the University of Washington.

1. The pertinent IACUC protocol must describe all surgeries¹ necessary to create the planned model. For example, a protocol might include a surgery, or surgeries, such as one craniotomy, implantation of a chamber/platform, implantation of an eyecoil, etc. If more than one surgery is required to create the model, the scientific or animal welfare justification must be included.
   
   
2. The IACUC recognizes that unanticipated events requiring surgery may occur. As such, the protocol should include provision for one or two surgical sessions in the event of the need for a repair or correction.
   
   
3. All additional potential surgeries require review and approval by the IACUC. Since additional surgeries would naturally be a result of unpredictable events, researchers may submit an application for additional surgeries immediately upon the need to conduct a surgery as described in item #2 above. Failure to obtain such approval will mean that an animal cannot have additional experimental surgery until IACUC approval can be obtained. Two surgical sessions for repair, or repairs, can be requested at one time. The application for approval must include the following:
   1. A justification of the scientific need for continuation of the specific animal in the study.
   2. A complete medical history of surgeries already conducted on the specific animal, including both experimental and clinical surgeries (including the surgery prompting the application even if it is scheduled but not yet conducted).
4. Owing to the seriousness of the decision to allow, or not to allow, an animal’s continuation in a study, decisions regarding additional surgeries as described above will be made in convened meetings of the IACUC.
   
   
5. Maintenance of cranial implants requires frequent cleaning as well as less frequent recording chamber debridement. Recording chamber debridement involves removing tissue in an existing craniotomy that impedes or obstructs the placement of transdural electrodes or guide tubes (which carry the electrodes to the brain parenchyma) under anesthesia.  The procedure is required at different intervals (weekly to monthly or even less frequently) for different animals, depending on the type of electrode and guide tube, the depth of the targeted neural structures and consideration of the superficial cortex in the chamber. Granulation tissue, scar tissue, mineralized fibrotic tissue and bone spurs from the edge of the craniotomy are removed.  The removal of scar tissue is often performed in layers under the guidance of a dissecting microscope.

   Cranial chamber debridement does not include extension of a craniotomy beyond its original margin.  It does not involve relocation of the recording cylinder.  It does not include a new craniotomy or an extension of an existing craniotomy past the confines of the original or placement of cranial bone screws to place a cylinder, and it does not include placement (or replacement) or cranial bone screws to re-anchor a recording cylinder over an existing craniotomy.

   Cranial chamber debridement is considered a necessary maintenance procedure and does not require specific IACUC approval for each debridement.

¹Surgery will be defined as a procedure performed using instruments on a living body that involves incision, excision, or suturing with the exception of cleaning and cranial chamber debridement as defined in #5.