Is it possible to use multiple GPU devices in a local area net within matlab?

I setup a local area network using 5 PC, each PC has a nvidia GPU card of GTX970. I tried to use Parallel Computing Toolbox of Matlab(2013a) to invoke the GPU resource in other PC within the network, but it failure. The matlab gave the error that no supported GPU device was found on this computer. However, it succeed to run gpuDevice on this computer. It seems that the cluster of GPU can be detected by parfor of spmd function. I hope someone can help me. Thanks!