The release of ink in Aplysia californica occurs selectively to long-lasting stimuli of ink gland motor cells.The firing pattern of the ink motor cells correlates well with the release behavior.With long-lasting and adequate strength depolarizing current, the neurons respond throughout the stimulus duration.For a weaker stimulus there can be a long latency before repetitive firing (Fig1).These firing features are captured in an HH-like biophysical model as developed by JH Byrne ([2], [3]).The model is based on the in vitro voltage-clamp experimental data obtained by Byrne.It accounts for the quantitative contribution which the ionic conductance mechanisms make to the firing patterns of the ink motor cells.For example, the long latency (Fig 1 B) reflects the time scale of the inactivation, BFK, of a transient A-type potassium current ([1]).