Chapters authored
Alzheimer-Like Cell Alterations after Vanadium Pentoxide Inhalation
Vanadium (V), a widely distributed transition metal, has been considered toxic, which depends on the valence of the compound. V pentoxide (V2O5) is considered the most harmful. Its long-term exposure produces neurotoxicity. Mice exposed to inhaled V2O5 displayed less tubulin+ in testicular cells and dendritic spines loss, cell death, and CA1 neuropil modifications, considered as the result of V interaction with the cytoskeleton, which made us suppose that V2O5 inhalation could initiate CA1 cell alterations comparable to what happen in the brains of Alzheimer disease (AD) patients. This study intends to demonstrate pyramidal CA1 cytoskeletal changes in rats which inhaled V2O5. Twenty rats were exposed to V2O5 0.02 M one hour, three times a week for several months. Our findings showed that V2O5-exposed rats had cell death that reached 56,57% after six months; we also observed collapsed strong argyrophilic nuclei and characteristic flame-shaped somas in all V2O5-exposed animals hippocampus CA1 compared to controls. We also found somatodendritic deformations. Neurite’s cytoskeleton exhibited visible thickening and nodosities and prominent dendritic spine loss. Our results demonstrate that V2O5 induces AD-like cell death with evident cytoskeletal and synaptic alterations.
Part of the book: Neurotoxicity
Melatonin Pretreatment Effect in a Parkinson Disease Experimental Model Induced by the Inhalation of Manganese in Mice
Parkinson disease (PD) is characterized by dopaminergic neuron loss of the substantia nigra compacta (SNc) and motor alterations. Here, we used the experimental model of inhalation of the mixture of manganese chloride (MnCl2) and manganese acetate Mn (OAc)3 for inducing PD. This model causes bilateral and progressive degeneration of the SNc dopaminergic neurons. Melatonin has antioxidant properties and it has been suggested that it contributes to the protective effect in neurodegenerative diseases. Therefore, we aimed to determine whether melatonin pretreatment protects against the Mn-induced alterations. Before Mn inhalation, three groups were trained for motor performance (1. control group, 2. Mn mixture exposed without pretreatment, and 3. melatonin-pretreated/Mn-exposed groups) for motor tests. The motor coordination was evaluated through the single-pellet reaching task and the beam-walking test. After five months, all the animals were sacrificed. Dendritic spines were counted in the striatum medium-sized spiny neurons and the number of TH-immunoreactive neurons in the SNc. Our findings show that the melatonin-pretreated animals had better motor coordination and less dendritic spines and TH immunoreactive neuron loss than the Mn-inhalation-only group. Therefore, melatonin pretreatment has a neuroprotective effect and could be considered an alternative treatment before the more severe PD symptoms appear.
Part of the book: Melatonin