A device for the implantation of multiple cellular deposits into a large volume of brain from a single cannula site

Current grafting techniques for the treatment of Parkinson's disease incompletely restore the dopaminergic innervation of the caudate/putamen and while, in successful cases, bradykinesia and rigidity are reduced, tremor is largely unaffected. Increasing the number of cellular deposits would allow grafted neurons to be dispersed more widely within the host brain. This might be expected to lead to a more complete reinnervation of the caudate/putamen and therefore a better clinical result. In order to increase the volume of brain accessible to reinnervation without increasing the number of needle passages through the cortex, we have designed a device which allows a Teflon tube to be extruded sideways from the end of a stainless steel cannula. Through this tube, cells can be implanted at some distance in any radial direction from the axis of the cannula. Using such a device we have made up to 12 deposits of lac-z-labeled cells via a single cannula entry into the rat brain, at distances of up to 5 mm from the axis of the cannula. We propose that a similar device could be used to graft embryonic neurons into the human brain.