The Adrenergic Innervation of the Labyrinth

Abstract

Using the method of Falck and Hillarp for the histocliemical demonstration of catecholamines, an adrenergic innervation is selectively shown in fresh tissue preparations of various parts of the labyrinth. Two different groups of adrenergic fibres are found: (1) A rich perivascular plexus continuous with the plexus of the basilar artery. It is only found around the labyrinthine artery and its greater brandies. (2) An extensive adrenergic network in the lamina spiralis ossea and underneath the vestibular sensory epithelia independent of blood vessels. It forms a dense terminal plexus in the area of the habenula perforata. With selective transection of the vestibular, cochlear or entire VIII nerve it could be demonstrated that these adrenergic fibres originate in the central nervous system and reach the periphery with the cochlear nerve. A possible interpretation of their functional significance is presented.