Microglia in the pineal gland of the neonatal rat: Characterization and effects on pinealocyte neurite length and serotonin content

✍ Scribed by Shih-Yen Tsai; J.A. McNulty

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 396 KB
• Volume: 20
• Category: Article
• ISSN: 0894-1491
• DOI: 10.1002/(sici)1098-1136(199707)20:3<243::aid-glia8>3.0.co;2-8

✦ Synopsis

Microglia in the pineal gland of 1-day-old Sprague-Dawley rats were examined by OX-42 immunocytochemistry and DiI-acetylated-LDL uptake in pineal cell suspension and were found to comprise 3-5% of the total cells in the pineal gland of the neonates. In order to investigate the effects of microglia on pinealocyte structure and function, microglia-depleted and microglia-enriched pineal cell cultures were generated from 1-day-old neonate by fluorescence activated cell sorting (FACS). After 7 days of culture, tissues were processed for either immunocytochemistry for pinealocyte Santigen and serotonin or high performance liquid chromatography to measure serotonin. Morphometric analysis of immunoreacted cells revealed that pinealocyte neurite length was enhanced in microglia-depleted cultures and was inhibited in a microglia-enriched environment (ANOVA, P , 0.001). Serotonin content of pineal cultures decreased in microglia-depleted cultures and was elevated in microglia-enriched cultures (ANOVA, P , 0.001) without any significant change in pinealocyte numbers. These findings are consistent with a working hypothesis that microglia function to mediate neuroendocrineimmune interactions of the gland.