In experiments where other elements are substituted on the Cu and Ba sites, evidence has shown that conduction occurs in the Cu(2)O planes while the Cu(1)O(1) chains act as charge reservoirs, which provide carriers to the CuO planes. However, this model fails to address superconductivity in the homologue Pr123 (praseodymium instead of yttrium). This (conduction in the copper planes) confines conductivity to the "a"-"b" planes and a large anisotropy in transport properties is observed. Along the "c" axis, normal conductivity is 10 times smaller than in the "a"-"b" plane. For other cuprates in the same general class, the anisotropy is even greater and inter-plane transport is highly restricted.