Inhibition of parasympathetic axonal sprouting in the cat submandibular gland by sympathetic axons

Summary The sprouting of parasympathetic axons into the submandibular sympathetic nerve trunk following sympathetic denervation has been investigated. It was found that a permanent sympathetic denervation was necessary in order for the sprouting to develop and be maintained: if reinnervation by adrenergic nerves was delayed, the sprouting developed but was reduced at longer survival times when the original innervation was reestablished. The evidence for suppression of the cholinergic sprouting by the adrenergic axons is discussed, as is the evidence that these sprouts arise from the submandibular gland.