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Spike, spike and burst, and burst but non-spike phase synchronizations of various oscillation patterns of intracellular calcium concentration were observed in a biological experiment on the cultured cardiac myocytes at 5-6 d of culture. The oscillations included periodic, nearly periodic, and non-periodic spiking or bursting patterns. In particular, a phase synchronization of chaotic oscillation was identified. As the coupling strength was decreased by application of heptanol, spike synchronization was changed into burst but non-spike synchronization. These experimental observations provide strong evidence for the existence of spike, burst, and chaos synchronization and transition from spike to burst synchronization in a real biological system.

Highlights Neuroimaging study of task-evoked state shift in schizophrenia. Salience signaling failure upon placing task demands in schizophrenic patients. Increased task-evoked insular output to the executive network. Increased task-evoked visual input to the insula. More severe negative symptoms were associated with stronger insula output.

As the value of a control parameter decreases, monostable bursting changes to monostable spiking via the coexistence of spiking and bursting in a Leech neuron model, and the attraction domain of the bursting decreases, while that of the coexisting spiking increases for coexisting behaviors. As the coupling strength increases, the two coupled Leech neurons with the coexisting spiking and bursting manifest transitions from non-synchronization to complete synchronization (CS) through a complex process, which is dependent of the values of the control parameter, cases of configurations (one neuron spiking and the other bursting, both bursting, and both spiking), and the initial values of the two neurons. The transition processes involve various spiking and bursting or chaos synchronization states for the first two cases given here, but contain only spiking patterns for the last case. Corresponding with the attraction domain, the probability of initial values that can lead to bursting patterns of CS decreases, but the probability of initial values that can induce spiking of CS increases for the former two cases, as the control parameter is decreased. This phenomenon can also be interpreted by the structure and volume of the attraction domain with which all initial values can only induce CS of spiking for case 3. The results may improve understanding of the synchronization dynamics of the coupled neurons with coexisting behaviors.