Activity-dependent enhancement in the reliability of correlated spike timings in cultured cortical neurons

To study the use-dependent modification of activity in neural networks, we investigated the spike timing by simultaneously recording activity at multi ple sites in a network of cultured cortical neurons. We used dynamical anal ysis to study the temporal structure of spike trains and the activity-depen dent changes in the reliability and reproducibility of spike patterns evoke d by a stimulus. We also used cross-correlation analysis to evaluate the in teractions of neuron pairs. Our main conclusions are that even when no obvi ous change in spike numbers can be seen, use-dependent modification occurs, either enhancing or reducing in the reliability and reproducibility of spi ke trains evoked by a stimulus, and the fine temporal structure of stimulus -evoked spike trains and interactions between neurons are also modified by tetanic stimulation.