This paper is concerned with issues related to the coupling between low-ffrequency nuclear modes and electronic emission in the bacterial reaction center of Rhodobacter sphaeroides. We have investigated the temporal evolution of the stimulated emission spectra of the excited state of the special pair bacteriochlorophyll dimer by means of computer simulation. To this purpose, we have carried out molecular dynamics simulations on a hydrated reaction center with the special pair in its ground and excited states, P and P*, respectively. Calculations of the time-dependent stimulated emission spectra has revealed an oscillatory behavior which is consistent with experiments (Vos et al.; Nature 1993, 363, 320; Biochemistry 1994, 33, 6750). The time scales of these nuclear vibrations are similar to those found experimentally. To a good approximation, both the protein environment and the special pair dimer couple to the P* --> P transition with oscillations of similar frequencies. This finding offers an insight on the nature of the nuclear oscillations and might have important implications for their complete understanding.