Progression of lipofuscin in neurons of human cortex of patients with mesial temporal lobe epilepsy: synaptic modifications and protein linked to neurodegenerative diseases along aging

• Grant number: 11/10958-1
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): August 01, 2011
• Effective date (End): January 31, 2013
• Field of knowledge: Biological Sciences - Morphology - Cytology and Cell Biology
• Principal researcher: Jorge Eduardo Moreira
• Grantee: Ana Beatriz Souza Nakayama
• Home Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Morphological and functional changes of neurons occur along aging, with increased incidence of neurodegenerative diseases. Following the evolution of the lipofuscin granules along three periods of life (20 to 28; 37 to 41; and 50 to 55 years old) of patients with mesial temporal lobe epilepsy, the present work investigated synaptic changes, as well as proteins associated with neurodegenerative diseases (alpha-synuclein and, tau), and the ubiquitin-proteossoma system in samples of cortex of these patients taken during surgeries for temporal lobe epilepsy. The proteins were chosen since ubiquitin is linked to the degradation of several intracellular proteins, while tau is associated with microtubles, and alpha-synuclein has a role in axonal transport and synaptic transmission. Electron microscopy, imunohistochemistry for light microscopy and western blot techniques will be used as procedures. The data obtained on lipofuscin so far in relation to the lipofuscin granules demonstrated that they seem to grow in volume, but not in number, with significant increase of the electron lucid fraction (lipidic). There is no difference in synaptic densities, alpha-synuclein, and ubiquitin expressions between the experimental groups. In addition, larger sampling for analysis by Western blot should give us more consistent results. Studies analyzing the progression of these factors during the aging of the cortex in patients with mesial temporal epilepsy are rare.