We compare the electronic structure of n-type and p-type dopable high-T, cuprates, namely the holedoped Ndl 4Ceo 2Sro 4Cu04 z (T*) system as well as the electron-doped Nd& "Ce"Cu04 z (T') and Sl 0 85Ndo»Cu02 z ("infinite-layer") systems. Investigations were done mainly by means of core-level and valence-band photoemission spectroscopy. Also we performed auxiliary measurements of Hall effect and magnetic susceptibility. From the investigations on the Cu-0 layers we propose that one criterion for electron dopability in high-T, cuprates is a comparatively high value of the Cu 3d Coulomb interaction Uzz. This is concluded from model calculations on core-level and valence-band spectra. Also the superconducting infinite-layer compound Sro 85Ndo»Cu02 q exhibits (besides a remarkably low Cu-0 hybridization) this enhanced value of Uqz. For the rare-earth layers of T' and T* we find small but characteristic differences in the electronic properties (Nd-0-hybridization and charge-transfer energy), which can be attributed to structural differences. Crystal-field splitting of Nd 4f levels and antiferromagnetic coupling of Nd'+ moments in Ndl 85Ceo»Cu04 z and Ndl 4Ce02Sr04Cu04 z have been investigated by evaluation of the magnetic susceptibility. The dopant ions cerium for T' and T* and neodymium for Sro 85Ndo»Cu02 z are found to be tetraand trivalent, respectively, which confirms again that the infinite-layer compound is an electron-doped cuprate.