  We present and compare the results of temperature-dependent electron
paramagnetic resonance (EPR) studies on Pr_1-x Ca_xMnO_3 for x = 0.64 which is
electron-doped with those on the hole doped x = 0.36 composition. The
temperature dependence of the various parameters obtained from the powder and
single crystal spectra show significant differences between the two manganites.
At room temperature the `g' parameter for the electron doped system is less
than the free electron `g' value `g_e', whereas for the hole-doped system it is
more than `g_e'. Further, the `g' value and the linewidth obtained from the
powder spectra as well as the single crystal spectra show different functional
dependences on temperature in the two systems. Quite strikingly, the peak
observed at T_{co} in the temperature dependence of the asymmetry parameter,
alpha, of the single crystal spectra in the hole-doped system is absent in the
electron-doped system. We understand this contrasting behaviour of the EPR
parameters in the two systems in terms of very different nature of microscopic
interactions in them.
