The effect of the transplanted pineal gland on the sympathetic innervation of the rat sublingual gland

Abstract

We investigated the effect of the pineal on sympathetic neurons that normally innervate the sublingual gland of the rat. When the pineal gland was transplanted into the sublingual gland, it remained as a distinct mass that was innervated by sympathetic axons. Injection of the retrograde tracer, Fast Blue, into the sublingual gland labelled sympathetic neurons in the ipsilateral superior cervical ganglion (SCG). Thirty per cent of all neurons labelled retrogradely by Fast Blue injection into transplanted pineal glands were immunoreactive for both neuropeptide Y (NPY) and calbindin. This combination is characteristic of sympathetic neurons innervating the pineal gland in its normal location, b..