A computational study of the interdependencies between neuronal impulse pattern, noise effects and synchronization

A Framework for Quantitative Modeling of Neural Circuits Involved in Sleep-to-Wake Transition

“…The analysis herein is tailored toward the effect of optogenetics on populations of neurons, and does not speculate on the synaptic strengths within the neural circuits. Works such as (40, 94) have addressed the integration of sleep homeostasis and Hodgkin–Huxley models for Hcrt neurons. The unification of a large-scale corticothalamic model, which merges sleep homeostasis and synaptic scaling with our notions of hierarchy, feedback, and redundancy, is beyond the scope of the current paper but an exciting future avenue.…”

“…Similarly, the limit cycle reciprocal interaction model (LCRIM) has considered dynamic system modeling and the consideration of feedback in the circadian modulation of the REM sleep (38, 39). The framework, and corresponding notion of feedback, presented herein is geared more so toward sleep-to-wake transition [rather than sleep homeostasis as conducted by Postnova et al (40), Fulcher et al (41)] and will consider the Hcrt system as well as the incorporation of optogenetics. The primary focus of our effort is to elucidate the complex interactions between the neural circuits involved in the sleep and arousal states.…”

Models of experimental epilepsy

“…5 Farklı beyin yapılarında veya yapıları arasında meydana gelen senkronizasyon veya osilatör aktivite anormalliklerinin; epilepsi, parkinson, şizofre-ni gibi birkaç nörolojik hastalıklar ile ilişkisi olabileceği bildirilmiştir. 6,7 Đlk olarak 1960'larda uluslararası epilepsi uzmanlarının bir araya gelmeleriyle epileptik nöbet-lerin sınıflandırılmasının temelleri atılmıştır. Klinik bilgiler ve elektroensefalografi (EEG) değişik-liklerine göre epilepsiler basitçe; jeneralize nöbet-ler (tonik klonik, miyoklonik, absans gibi), parsiyel nöbetler (basit parsiyel, kompleks parsiyel gibi) ve sınıflandırılamayan nöbetler (uykuda oluşan bazı tonik klonik nöbetler gibi) olarak ayrılırlar.…”

Computer Simulation of Noise Effects of the Neighborhood of Stimulus Threshold for a Mathematical Model of Homeostatic Regulation of Sleep-Wake Cycles

“…Neural noise is a general term that designates random influences on the transmembrane voltage of single neurons and by extension of the firing activity of neural networks. This noise can influence the transmission and integration of signals from other neurons and alter the firing activity of neurons in isolation [2][3][4], and there are some significant effects near bifurcation points [5,6], the weak neural noise, that seem to be less relevant when the neurons operate in spike generating regime for a suprathreshold; however, the situation is completely different in the neighborhood of threshold where noise can induce significant changes in the impulse patterns; furthermore, in the central neural system, the neurons often work in the neighborhood of threshold, but neurons are heterogeneous and noise is inevitable [7]. Sleep is essential for the maintenance of the brain and the body, yet many features of sleep are poorly understood and mathematical models are an important tool for probing proposed biological mechanisms; in addition, noise is an inevitable factor in real neuronal systems, which plays an important role in spatiotemporal dynamics of neuronal networks, for nearly a century of study; some regulation nonlinear sleep models about circadian [8], diversity-induced resonance [9], temporal dynamics [10], physiological substrates [11,12], and more have been proposed to investigate the neural regulatory mechanism for sleep-wake cycle; however, sleep and its underlying processes still hold many mysteries; it remains unclear how identified brain regions interact to bring about the different stages of sleep and wakefulness, how the timing of sleep depends on the length of time spent awake and work load, and how pathologies associated with sleep, such as narcolepsy, arise [13].…”