Innervation of the pineal gland in the mongolian gerbil (Meriones unguiculatus). A fluorescence microscopical study.
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.
D000818:Animals; D002395:Catecholamines / Q000032:analysis; D003239:Connective Tissue Cells; D005260:Female; D005849:Gerbillinae / Q000033:anatomy & histology*; D008297:Male; D008856:Microscopy, Fluorescence; D009412:Nerve Fibers; D010870:Pineal Gland / Q000166:cytology / Q000502:physiology; D012701:Serotonin / Q000032:analysis
D002395:Catecholamines; D012701:Serotonin