Quantitative analysis of the sympathetic efferent activity to characterize the integrative function of the sympathetic ganglion.

Using the concept of the Markov dependency, we analyzed the spontaneous activity in the pre- and postganglionic nerve trunks of the feline superior cervical ganglion. The time structure (order and value of time dependency) of the sequence of compound action potentials was determined. The analysis revealed that the time dependency of the postganglionic activity is of higher order and is generally more consistent than that of the preganglionic one. The difference in orders and values between the pre- and postganglionic activities was found to be a measure of the integrative function of the ganglion. A transformation by the ganglion of some additional information, inaccessible in the time structure of the preganglionic activity, seems to underlie this difference.