Development of spatially separated coculture system of the sympathetic neuron and the cardiomyocyte

Rat superior cervical ganglion (SCG) neurons and the ventricular myocytes (VMs) were cocultured in chambers made of polydimethylsiloxane. The chambers were placed on a microelectrode array (MEA) substrate and connected with a pathway. Twenty-four hours after dissemination of the VMs, neurites of the SCG neurons outgrew through the pathway and reached the VMs. Spontaneous electrical activities of the SCG neurons and the VMs were observed several days after the dissemination. Constant-voltage stimulation (1 V, 1 ms, biphasic square pulses) was applied to the SCG neurons at the frequency of 10 Hz using 32 electrodes. Contraction rate of the VMs increased by 153 ± 110% immediately after the stimulation to the SCG neurons was stopped. Then contraction rate gradually decreased and returned to almost the same rate as before the stimulation 5 min after the stimulation. Propranolol (β-adrenergic receptor antagonist) prevented contraction rate of the VMs from increasing after electrical stimulation to the SCG neurons. These results suggest that neuromuscular junctions were formed between the SCG neurons and the VMs and that this coculture system can be utilized in the research of cell–cell interactions between the sympathetic neurons and the cardiomyocytes. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.