Optimization of the isolation of neuromelanin granules and morphological analysis of the neuromelanin isolated of substantia nigra

• Grant number: 11/07946-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2011
• End date: December 31, 2011
• Field of knowledge: Health Sciences - Medicine - Pathological Anatomy and Clinical Pathology
• Principal Investigator: Renata Elaine Paraizo Leite
• Grantee: Mariana Molina
• Host Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Currently, many basic questions remain to be answered about neuromelanin (NM) in the brain. It is unclear why only some human dopamine neurons produce NM within their cytoplasm. Little is also known about the structure of NM, and the understanding of its genesis and function within the cell remains speculative. In this way, this work aims to optimize the protocol for isolation of NM granules of the substantia nigra of the brain of cognitively normal individuals using the protocol established by Tribl et al. (2005) with modifications and analyze the morphological characteristics and quality of the NM granules. The frozen material to be used will be provided by the Brain Bank of the Aging BrainStudy Group of the Sao Paulo. The granules will be isolated from the substantia nigra of five people aged 50 years or more at time of death. The granules will be isolated using subcellular fractionation. The quality of isolated granules, the preservation and the ultrastructural characteristics of the granules will be monitored by electron microscopy. The protocol to be used includes several modular steps that can be easily adjusted to any other organelle and the may work for different types of material. Furthermore, a closer look at the cellular organelles can contribute to understand the structure and development of the NM.