This Intracerebral Guide Cannula targets an implant site and support a microdialysis probe during in vivo sampling experiments in the brain. Guides are used for studies in awake, freely moving animals.
The guide is as long as the probe cannula. When a probe is placed inside, only the dialysis membrane extends beyond the end of the guide cannula. When the guide is implanted, it is placed just above the tissue that will eventually be sampled by microdialysis. After the animal recovers from the surgery (3-5 days), the edema will subside and ruptured blood vessels will have been sealed. Any glial cell formation will be restricted to the tissue disrupted by insertion of the guide and not the target site. Damage caused by insertion of the probe will be restricted to a small path that is the length and diameter of the dialysis membrane. This is considerably less trauma for the brain than the damage caused by drilling a hole in the skull, puncturing the dura, and then inserting the longer and wider intracerebral guide. In many cases, levels of targeted analytes will achieve steady state within a few hours. After sampling, the probe can be removed and reinserted at a later time.
The Intracerebral Guide Cannula can be mounted directly onto the skull using stereotaxic surgical techniques. It can be held by the clamp assembly as shown on the drawing above (far left). The clamp assembly mounts on the clamp rod which is in turn mounted onto the micromanipulator of the stereotaxic frame.