How does the hippocampal formation contribute to the development of epilepsy?5 answersThe hippocampal formation plays a crucial role in the development of epilepsy by being involved in the generation of epileptic seizures through various mechanisms. Abnormalities in the structure and function of the hippocampus, such as impaired neurogenesis, abnormal dendritic integration, and mossy fiber sprouting, contribute to the onset of epilepsy. These alterations lead to an imbalance in excitatory and inhibitory mechanisms in the neocortex, making the hippocampus more susceptible to factors like hypoxia and oxidative stress, which can trigger epileptic activity. Additionally, studies have shown that hippocampal cells cultured in physiological conditions can spontaneously exhibit epileptiform patterns, resembling those observed in epilepsy models, highlighting the hippocampus's significance in epileptogenesis.
What role does the cortex play in the development of neural networks?5 answersThe cortex plays a crucial role in the development of neural networks by providing a unique architecture that enables complex cognitive tasks. It is essential for animals to perform tasks that involve processing different types of inputs simultaneously, akin to how the cerebral cortex in the brain handles various tasks within the same learning system. Additionally, the cortex's interplay of chaotic and stable oscillatory neurodynamics influences information processing and structural development. Early sensory experiences, mediated by subplate neurons, shape and sculpt the neural connections in the cerebral cortex, particularly in sensory areas, highlighting the long-lasting effects of early interactions on cortical development. Furthermore, the development of structured network activity in the human neocortex follows stable genetic programming, showcasing the importance of intrinsic factors in shaping functional network activity.
What's cortical thinning?4 answersCortical thinning refers to the reduction in the thickness of the cerebral cortex, which is the outer layer of the brain that plays a crucial role in cognitive functions. Studies have shown that cortical thinning is a normal part of aging, but accelerated thinning in specific regions may be indicative of neurodegenerative diseases such as Alzheimer's disease and dementia with Lewy bodies. In preschool-onset depression, maladaptive guilt has been associated with structural alterations in the anterior insula and dorsomedial prefrontal cortex. Additionally, high-grade carotid artery stenosis has been found to be associated with cortical thinning in the hemisphere ipsilateral to the stenosis. Furthermore, epilepsy patients with postictal generalized electroencephalographic suppression (PGES) have shown reduced cortical thickness in specific brain regions. These findings suggest that cortical thinning can be a biomarker for various neurological conditions and may provide insights into the underlying pathophysiology of these disorders.
Patients with corticodependency more likely to develop myelotoxicity?5 answersPatients with corticodependency may be more likely to develop myelotoxicity.
How does cortical electrical activity arises?5 answersCortical electrical activity arises through the interaction of various factors. The development of cortical EEG activity, membrane and action potentials, and surface steady potentials occurs from the early postnatal days in rats, with resting cellular membrane potentials and surface steady potentials present from the first day on. Action potentials from cortical neurons are detectable from the fourth day and are preceded by rhythmical oscillations in membrane potential resembling excitatory postsynaptic potentials. In addition, a continuum model of the electrical activity of the cerebral cortex predicts the occurrence of a resonance in the gamma range near 40 Hz, which emerges due to refinements in the model, including the modulation of synaptic strength and parameters that match physiological measurements. The coordination of neuronal activity in an isolated cortical slab during the onset of seizure spikes is also observed, with convulsive shifts in membrane potential corresponding to electrocorticograms of convulsive activity waves. These findings suggest that cortical electrical activity arises from the interplay of synaptic connections, membrane potentials, and coordinated neuronal activity.
What causes neurons to grow?8 answers