The innervation of the mammalian adrenal gland.

TLDR

Early studies oversimplified adrenal innervation, but nerve‑fiber tracing introduced in the 1970s revealed its true complexity. The article reviews existing literature on medullary and cortical adrenal innervation. The authors review prior reports and then map adrenal medulla innervation in rodents and primates with retrograde fluorescent tracer techniques. The study found that adrenal medulla in rodents, primates, and a third species receives sympathetic, parasympathetic, and afferent innervation, and it briefly discusses how neural control may link cortical and medullary secretions.

Abstract

Early conflicting reports and the lack of sensitive anatomical methods have led to an oversimplified view of adrenal gland innervation. It was not until the introduction of nerve fibre tracing techniques in the mid-1970s that the true complexity of adrenal innervation began to emerge. The first part of this article comprises a brief review of these and other relevant reports dealing with both medullary and cortical innervation. In the second part a detailed account is given of the work undertaken in Rex Coupland's Department relating to the innervation of the rodent and primate adrenal medulla using a retrograde fluorescent tracer technique. It was concluded that, in all 3 species studied, the adrenal medulla receives a sympathetic and parasympathetic efferent and an afferent innervation. The possible interrelationship between neural control of cortical and medullar secretions is discussed briefly.