Serotonin (5-hydroxytryptamine, 5-HT), a precursor for melatonin production, is produced abundantly in the pineal gland of all vertebrate animals. The synthesis of 5-HT in the pineal gland is rate limited by tryptophan hydroxylase 1 (TPH1) whose activity displays a twofold increase at night. Earlier studies from our laboratory demonstrate that pineal 5-HT secretion exhibits dynamic circadian rh...

The blind cavefish Astyanax mexicanus undergoes bilateral eye degeneration during embryonic development. Despite the absence of light in the cave environment, cavefish have retained a structurally intact pineal eye. We show here that contrary to visual degeneration in the bilateral eyes, the cavefish pineal eye has conserved the ability to detect light. Larvae of two different Astyanax cavefish...

Pineal parenchymal tumors are rare. Of the three types of pineal parenchymal tumors, pineocytomas are the least aggressive and are not known to diffusely disseminate. In this paper, we report the successful treatment of a case of pineocytoma with diffuse leptomeningeal relapse following initial stereotactic radiotherapy. A 39-year-old female presented with headaches, balance impairment, urinary...

1. The action of N-2'-chloroethyl-N-ethyl-2-methyl benzylamine (xylamine) on rat pineal gland sympathetic innervation was examined. 2. This alkylating agent caused a concentration-dependent increase in pineal gland N-acetyltransferase (NAT) activity in neurologically intact pineal glands that was suppressed in glands previously subjected to bilateral superior cervical ganglionectomy. 3. Xylamin...

In the present work, coexpression of vimentin (VIM) and glial fibrillary acidic protein (GFAP) is demonstrated in the glial cells of the adult rat pineal gland. Serial consecutive Epon semithin sections (0.5 microns thick) were alternately immunostained for VIM and GFAP. GFAP positive cells and processes were found in the proximal region of the pineal gland, near the pineal stalk. Most of these...

Exposure to light reduces the ability of the rat pineal gland to synthesize melatonin and decreases the weight of the gland. When the sympathetic nerves to the pineal gland are cut, light no longer has an effect on melatonin synthesis or pineal weight. The response of the gland does not require that the gonads or the pituitary gland be present.

There has been relatively little research conducted on pineal melatonin production in laboratory mice, in part, due to the lack of appropriate assays. We studied the pineal and plasma rhythm, response to light, adrenergic stimulation, and metabolism of melatonin in CBA mice. With the use of a sensitive and specific melatonin RIA, melatonin was detected in the pineal glands at all times of the d...

Failure of isoproterenol (ISO) injections to raise pineal melatonin content has generated doubt about beta-adrenergic control of the melatonin rhythm in Syrian hamsters. However, the effect of ISO injected at night after light-induced reduction of pineal melatonin has not been reported. In this study, light exposure began at 6 1/4 h into one (normally 10-h) dark phase. The hamsters were injecte...

PURPOSE To use MR imaging in the analysis of the size of the normal pineal gland in infants, children, and adolescents. METHODS We retrospectively analyzed the size of the pineal gland in 249 patients (129 male and 120 female) aged 2 weeks to 20 years old. The maximum length (L), height (H), and width (W) of the gland were determined from a combination of sagittal, coronal, and axial MR image...