Veratridine increases the survival of retinal ganglion cells in vitro

Neuronal cell death is an important phenomenon involving many biochemical pathways. This degenerative event has been studied to understand how the cells activate the mechanisms that lead to self-destruction. Target cells and afferent cells play a relevant role in the regulation of natural cell death. We studied the effect of veratridine (1.5, 3.0, 4.5 and 6.0 µM) on the survival of neonatal rat retinal ganglion cells in vitro. Veratridine (3.0 µM), a well-known depolarizing agent that opens the Na+ channel, promoted a two-fold increase in the survival of retinal ganglion cells kept in culture for 48 h. This effect was dose-dependent and was blocked by 1.0 µM tetrodotoxin (a classical voltage-dependent Na+ channel blocker) and 30.0 µM flunarizine (a Na+ and Ca2+ channel blocker). These results indicate that electrical activity is also important for the maintenance of retinal ganglion cell survival in vitr

Demência semântica: avaliação clínica e de neuroimagem. Relato de caso Semantic dementia: clinical and neuroimaging evaluation. Case report

A demência semântica é uma síndrome clínica que faz parte do grupo das degenerações lobares frontotemporais. Relatamos o caso de um homem de 63 anos que aos 57 anos inicia comprometimento da memória semântica tanto para material visual quanto principalmente verbal. Alterações leves de comportamento estavam presentes e relacionadas com reações exageradas a estímulos dolorosos e comportamentos repetitivos. Os exames de neuroimagem estrutural e funcional evidenciaram comprometimento bitemporal assimétrico, predominando à esquerda. Diagnóstico diferencial deve ser feito com a doença de Alzheimer, outros representantes do grupo das degenerações lobares frontotemporais e qualquer síndrome que se apresente com uma afasia fluente progressiva.<br>Semantic dementia is a clinical syndrome in the spectrum of frontotemporal lobar degeneration group. We report on a 63 years old man who presented with memory disorder of semantic nature for visual and mainly verbal material when he was 57 years old. Mild behavior impairment was present and related to exaggerated responses to algic stimuli and repetitive behavior. Structural and functional neuroimaging methods disclosed asymmetric bitemporal damage, mainly on the left. Differential diagnosis should be considered with Alzheimer's disease, another subtypes of the frontotemporal lobar degeneration group and any other syndrome that presents with a fluent aphasic progressive disorder