Based on recent calcium imaging studies, Wilson and Callaway proposed to model an isolated dopaminergic cell using chains of coupled oscillators. Unlike in other models, they assume that dendritic as well as somatic compartments are capable of autonomous oscillations. All compartments are strongly electrically coupled. The variation of a cross section diameter along the cell yields the variation in natural frequencies of oscillators in the chain. The model was shown to reproduce many of the experimental observations. In particular, it captures well the basic features of the rhythmic single spiking, the most common firing pattern in vivo, and displays a spike frequency adaptation. Both experimental data and simulations show pronounced transient dynamics following a perturbation of steady state oscillations. Our analysis explains the mechanism of synchronous oscillations of the membrane potential and calcium concentrations in the somatic and all dendritic compartments. We also give a detailed analytical description of the transient dynamics. In particular, we show that the duration of transients is directly proportional to the strength of coupling. Our results are based on the geometric theory for singularly perturbed systems, asymptotic expansions, and the Lyapunov's method. It is the latter, that reveals the nature of transients and characterizes the steady state oscillations. This is joint work with N. Kopell.