Background: The 6-OHDA nigro-striatal lesion model has already been related to disorders in the excitability and synchronicity of neural networks and variation in the expression of transmembrane proteins that control intra and extracellular ionic concentrations, such as cation-chloride cotransporters (NKCC1 and KCC2) and Na+/K+-ATPase and, also, to the glial proliferation after injury. All these non-synaptic mechanisms have already been related to neuronal injury and hyper-synchronism processes.
Objective: The main objective of this study is to verify whether mechanisms not directly related to synaptic neurotransmission could be involved in the modulation of nigrostriatal pathways.
Objective: Amygdala has been demonstrated as one of the brain sites involved in the control of cardiorespiratory functioning. The structural and physiological alterations induced by epileptic activity are also present in the amygdala and reflect functional changes that may be directly associated with a sudden unexpected death. Seizures are always associated with neuronal damage and changes in the expression of cation-chloride cotransporters and Na/K pumps.
View Article and Find Full Text PDFThere are no clinical interventions to prevent post-injury epilepsy, a common and devastating outcome after brain insults. Epileptogenic events that run from brain injury to epilepsy are poorly understood. Previous studies in our laboratory suggested Proechimys, an exotic Amazonian rodent, as resistant to acquired epilepsy development in post-status epilepticus models.
View Article and Find Full Text PDFExternal electric fields (E) induce a spatially heterogeneous variation in the membrane potential (ΔV) of cardiomyocytes that, if sufficiently large, results in an action potential and contraction. Insights into the phenomenon of ΔV induction by E have been classically gained with electromagnetic models due to the lack of adequate experimental approaches. However, it is not clear yet how reliable these models are.
View Article and Find Full Text PDFCommonly used methods to visualize the biological structure of brain tissues at subcellular resolution are confocal microscopy and two-photon microscopy. Both require slicing the sample into sections of a few tens of micrometers. The recent developments in X-ray microtomography enable three-dimensional imaging at sub-micrometer and isotropic resolution with larger biological samples.
View Article and Find Full Text PDFNeurogenesis impairment is associated with the chronic phase of the epilepsy in humans and also observed in animal models. Recent studies with animal models have shown that physical exercise is capable of improving neurogenesis in adult subjects, alleviating cognitive impairment and depression. Here, we show that there is a reduction in the generation of newborn granule cells in the dentate gyrus of adult rats subjected to a chronic model of epilepsy during the period of brain development.
View Article and Find Full Text PDFNonsynaptic mechanism changes, particularly the enhancement of NKCC1 expression in the dentate gyrus (DG) after 4weeks of ethanol consumption, motivate the present work, in which rats were submitted to a period of chronic consumption (12weeks). Four groups of six animals (6-week-old male Wistar rats) were formed, including the control (C), ethanol 1 (E1), ethanol 2 (E2) and ethanol 3 (E3) groups. The rats in the E1, E2 and E3 groups were treated daily with a 30% v/v solution of ethanol, administered via oral gavage (1.
View Article and Find Full Text PDFThe excitability of neuronal networks is strongly modulated by changes in pH. The origin of these changes, however, is still under debate. The high complexity of neural systems justifies the use of computational simulation to investigate mechanisms that are possibly involved.
View Article and Find Full Text PDFNon-synaptic mechanisms are being considered the common factor of brain damage in status epilepticus and alcohol intoxication. The present work reports the influence of the chronic use of ethanol on epileptic processes sustained by non-synaptic mechanisms. Adult male Wistar rats administered with ethanol (1, 2 e 3 g/kg/d) during 28 days were compared with Control.
View Article and Find Full Text PDFThe important role of cation-chloride co-transporters in epilepsy is being supported by an increasing number of investigations. However, enormous complexity is involved since the action of these co-transporters has effects on the ionic homeostasis influencing directly the neuronal excitability and the tissue propensity to sustain seizure. To unravel the complex mechanisms involving the co-transporters action during seizure, this paper shows simulations of non-synaptic epileptiform activity and the effect of the blockage of the two different types of cation-chloride co-transporters present in the brain: Na, K and 2Cl co-transporter (NKCC) and K and Cl co-transporter (KCC).
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