Impact of stimuli distribution on neural network responses

In this study we investigated the relationship between stimulus regularity and observed responses in a biological neural network of dissociated cortical rat neurons plated over Micro-Electrode Arrays (MEAs). In particular, the intervals between identical stimuli in our experiments followed a 1/f^β distribution, and regularity increased with the value of β (values tested were 0, 0.5, 1, 1.5, ∞). Comparisons occurred on the correlation between low-passed (rectangular window, 0.1s in length) stimulation trains and network-wide spike trains. Our results show that cultures are largely unable to synchronize network-wide responses with regular stimulation at the considered stimulation rate (0.5Hz), while this occurs to a much higher degree for irregular stimulations.