Electrophysiological and morphological characterization of neurons in stellate ganglion of cats.

We have studied the general morphology of cat stellate ganglion cells in relation to the synaptic input that each neuron receives. Horseradish peroxidase (HRP) was injected intracellularly into single neurons of the isolated cat stellate ganglia. Neurons of the stellate ganglion receive synaptic information from central and peripheral nerves. Electrical stimulation of the preganglionic nerves (T3 ramus), and postganglionic stimulation of the ventral or dorsal ansa subclavia, evoked graded excitatory responses that led to the discharge of one or more action potentials. The neurons receiving synaptic input from preganglionic and postganglionic nerves have a complex dendritic morphology. These neurons were located close to the postganglionic nerves and had an axon emerging from these nerves. Other neurons located closer to the preganglionic nerves had no identifiable axons leaving the ganglion and could not be excited antidromically by electrical stimulation. These neurons appear to be interneurons. These results indicate that neurons of the cat stellate ganglion are organized in a complex fashion that could be important in the integrative properties of these neurons.