An effective two-dimensional dynamic interaction is developed which incorpo
rates screening of electrons by plasmas and by optical phonons to discuss t
he nature of the pairing mechanism leading to superconductivity in layered
electron doped cuprates. The system is treated as an ionic solid containing
layers of electrons as carriers and a model dielectric function is set up
which fulfils the appropriate sum rules on the electronic and ionic polariz
abilities. Estimate of the Coulomb pseudo-potential (mu* = 0.24), describin
g the screening effects on superconductivity is due to reduced electron den
sity and large value of the optical dielectric constant as well the effecti
ve mass of electrons. The electron-phonon coupling constant (lambda) is eva
luated as 1.5 which infers strong strength of coupling. Following strong co
upling theory, the superconductivity transition temperature of optimally do
ped Nd-Ce-CuO is estimated as 30 K and the energy gap ratio is larger than
the BCS value. The isotope exponent, coherence length and magnetic penetrat
ion depth are also estimated. The implications of the model and its analysi
s are discussed.