Innervation of the pineal gland in the mongolian gerbil (Meriones unguiculatus). A fluorescence microscopical study

• Published in: Cell and tissue research Vol. 187; no. 2; p. 235
• Main Authors: Nielsen, J T, Møller, M
• Format: Journal Article
• Language: English
• Published: Germany 24.02.1978
• Subjects: Animals; Catecholamines - analysis; Connective Tissue Cells; Female; Gerbillinae - anatomy & histology; Male; Microscopy, Fluorescence; Nerve Fibers; Pineal Gland - cytology; Pineal Gland - physiology; Serotonin - analysis
• ISSN: 0302-766X
• DOI: 10.1007/BF00224367

The innervation of the pineal gland in the Mongolian gerbil, Meriones unguiculatus, was investigated light microscopically by the Falck-Hillarp fluorescence technique and by conventional light microscopy. The pineal gland displayed a superficial portion just beneath the confluens sinuum and a deep part (lamina intercalaris) connected by a slender pineal stalk, which contained pinealocytes. The superficial part of the pineal gland consisted of dark-stained pinealocytes arranged in lobules, and separated by interstitial cells and connective tissue spaces. Many larger chromophobe cells were scattered throughout this region. A heavy catecholaminergic innervation of the superficial portion of the pineal organ, probably via the conarian nerve, with green fluorescent nerve fibres showing excitation/emission maxima of 415/475 nm was observed. Green fluorescent nerve fibres were also observed in the pineal stalk, from where some fibres turned rostrally indicating a nervous connection between the brain and the pineal organ. The pinealocytes showed a yellow fluorescence displaying a broad excitation curve with a maximum of 380-430 nm and an emission maximum at 505 nm. This indicates the presence of both serotonin and a catecholamine in the pinealocytes. Yellow fluorescence of the cells in the lamina intercalaris was also observed.