We study the biochemical processes involved in scaffold-mediated crosstalk between the cAMP and the Raf-1/MEK/ERK pathways. We model the system by a continuous time Markov chain with levels and analyse properties using Continuous Stochastic Logic and the symbolic probabilistic model checker PRISM. We consider two kinds of properties of the model, causal events and pulsating behaviour, and, in order to formulate these properties, we enrich the model with trend formulas. The system is currently under wet-lab investigation and our approach was developed in collaboration with the experimentalists.