In a series of papers, we have proposed a dynamical model for gap junction-coupled networks of class I^* neurons, and investigated its dynamic characters. We found various dynamic states in a model neural network with diffusively coupled class I¤ neuron models, called μ-models. Among others, hierarchies of intermittent transitions attracted attention in relation with real brain dynamics. This paper is devoted to report a mechanism of the first transition appeared in the intermittenly transitory dynamics among an all-synchronized state, various metachronal waves and a weakly chaotic state. We clarify that this intermittent transition is described as an in-out intermittency
