Innervation of the rat pineal gland by nerve fibres originating in the sphenopalatine, otic and trigeminal ganglia. A retrograde in vivo neuronal tracing study

Abstract

-The innervation of the rat pineal gland from the sphenopalatine, otic, superior cervical and trigeminal ganglia was investigated in animals by use of in vivo retrograde tracings. A solution of 2 % Fluorogold was iontophoretically injected into the superficial pineal gland in a series of Wistar rats. After a survival time of 4-10 days, the animals were fixed by perfusion and the brains, sphenopalatine, otic, superior cervical and trigeminal ganglia were investigated with a fluorescence microscope. Many retrogradely labelled perikarya were found in the superior cervical ganglia, but a smaller number of neurones were also labelled in the sphenopalatine, otic and trigeminal ganglia. Injections of the tracer into the subarachnoidal space were used as the control for unspecific uptake and transport of the tracer. The input to the pineal gland from the parasympathetic sphenopalatine and otic ganglia might be involved in the regulation of the annual rhythms of the pineal gland. The projections from the sensory trigeminal ganglion could be involved in the control of the blood flow of the gland.

Generation of the Melatonin Endocrine Message in Mammals: A Review of the Complex Regulation of Melatonin Synthesis by Norepinephrine, Peptides, and Other Pineal Transmitters

“…However, localization of pinealopetal fibers originating in the pterygopalatine and the otic ganglia (Shiotani et al, 1986;Møller and Liu, 1999) together with the demonstration of pineal cholinergic fibers in the rat (Eranko et al, 1970), ferret (David and Herbert, 1973), rabbit (Romijn, 1973), monkey (David and Kumar, 1978), and cow (Phansuwan-Pujito et al, 1990 have demonstrated the occurrence of a parasympathetic input to the pineal gland. Besides ACh, VIPergic fibers originating from parasympathetic ganglia have also been observed in the rodent pineal gland (Shiotani et al, 1986;Møller and Liu, 1999). In addition, demonstration of receptors and biochemical effects of cholinergic and VIPergic ligands in the pineal gland (see Sections VI.A.…”

“…Retrograde tracing studies have demonstrated that the trigeminal ganglia project directly to the rodent pineal gland (Shiotani et al, 1986;Reuss et al, 1992a;Møller and Liu, 1999;Reuss, 1999). These fibers contain sP, CGRP, and PACAP.…”

The Melatonergic System in Mood and Anxiety Disorders and the Role of Agomelatine: Implications for Clinical Practice

“…Indeed, early studies demonstrated that, besides SCN innervation, the pineal gland receives projections from sphenopalatine, otic and trigeminal ganglia [60], which have been reported to secrete substance P [61]. Recent works demonstrated that pinealocytes are enriched with substance P receptors [62] and that substance P may inhibit norepinephrine-induced AANAT activation and melatonin secretion, though it does not impair basal levels of AANAT functioning [63].…”

Macro- and Microstructure of the Superior Cervical Ganglion in Dogs, Cats and Horses during Maturation

“…The SCG, which is a paravertebral ganglion, provides sympathetic input to the head and neck as well as to the mandible, submandibular glands, pineal and eyes (second and third order control) in laboratory animals [Luebke and Wright, 1992;Hubbard et al, 1999;Moller and Liu, 1999;Hayakawa et al, 2000;Ladizesky et al, 2000]. In rats, the SCG is an attractive model because it is easily located and is used as a model to investigate neurobiological disorders.…”