Prelude. Cycle 1. Introduction. Cycle 2. Structure defines function. Cycle 3. Diversity of cortical functions is provided by inhibition. Cycle 4. Windows on the brain. Cycle 5. A system of rhythms: from simple to complex dynamics. Cycle 6. Synchronization by oscillation. Cycle 7. The brain's default state: self-organized oscillations in rest and sleep. Cycle 8. Perturbation of the default patterns by experience. Cycle 9. The gamma buzz: gluing by oscillations in the waking brain. Cycle 10. Perceptions and actions are brain state-dependent. Cycle 11. Oscillations in the "other cortex:" navigation in real and memory space. Cycle 12. Coupling of systems by oscillations. Cycle 13. The tough problem. References.

Rhythms of the brain

This book explains the relationship of electrophysiology, nonlinear dynamics, and the computational properties of neurons, with each concept presented in terms of both neuroscience and mathematics and illustrated using geometrical intuition In order to model neuronal behavior or to interpret the results of modeling studies, neuroscientists must call upon methods of nonlinear dynamics This book offers an introduction to nonlinear dynamical systems theory for researchers and graduate students in neuroscience It also provides an overview of neuroscience for mathematicians who want to learn the basic facts of electrophysiology "Dynamical Systems in Neuroscience" presents a systematic study of the relationship of electrophysiology, nonlinear dynamics, and computational properties of neurons It emphasizes that information processing in the brain depends not only on the electrophysiological properties of neurons but also on their dynamical properties The book introduces dynamical systems starting with one- and two-dimensional Hodgkin-Huxley-type models and continuing to a description of bursting systems Each chapter proceeds from the simple to the complex, and provides sample problems at the end The book explains all necessary mathematical concepts using geometrical intuition; it includes many figures and few equations, making it especially suitable for non-mathematicians Each concept is presented in terms of both neuroscience and mathematics, providing a link between the two disciplines Nonlinear dynamical systems theory is at the core of computational neuroscience research, but it is not a standard part of the graduate neuroscience curriculum - or taught by math or physics department in a way that is suitable for students of biology This book offers neuroscience students and researchers a comprehensive account of concepts and methods increasingly used in computational neuroscience

/pdf/dynamical-systems-in-neuroscience-51dkewn57v.pdf

Dynamical Systems in Neuroscience

Neuronal activity in the brain gives rise to transmembrane currents that can be measured in the extracellular medium. Although the major contributor of the extracellular signal is the synaptic transmembrane current, other sources — including Na+ and Ca2+ spikes, ionic fluxes through voltage- and ligand-gated channels, and intrinsic membrane oscillations — can substantially shape the extracellular field. High-density recordings of field activity in animals and subdural grid recordings in humans, combined with recently developed data processing tools and computational modelling, can provide insight into the cooperative behaviour of neurons, their average synaptic input and their spiking output, and can increase our understanding of how these processes contribute to the extracellular signal.

/pdf/the-origin-of-extracellular-fields-and-currents-eeg-ecog-lfp-2e79zygxj0.pdf

The origin of extracellular fields and currents — EEG, ECoG, LFP and spikes

Interneurons of the hippocampus

EEG alpha oscillations: The inhibition–timing hypothesis

In this study, we have demonstrated the stand-off detection of sulfur hexafluoride by the Radar resonance multi-photon ionization process. In order to obtain a well defined spectral signature, the sulfur hexafluoride molecules are fi rst dissociated by a focused pulsed Nd:YAG laser to sulfur difluoride molecules, which are then ionized by a pulsed, frequency tunable, narrow linewidth laser emitting in the ult raviolet. At the wavelength 269.5 nm, a concentration of 10 % of sulfur hexafluoride has be en detected and the spectral signature shows some overlap with a carbon dioxide resonant spectral line. At 322.45 nm, we achieve better spectral definition. Based on successes usin g a similar approach for trace nitric oxide detection, we expect to be able to extend this appr oach to the detection of trace levels of SF 6 in the atmosphere for greenhouse gas monitoring.

Sulfur hexafluoride detection by Radar Resonance Enhanced Multiphoton Ionization

Adjoint optimization methods have proven successful for the control of turbulence and boundary layers and in the design of airfoils and aircraft. In this paper, the adjoint equations are extended to the problem of controlling steady, inviscid, supersonic flow with volumetric source terms in the Euler equations, that is, mass, momentum, and energy addition. The adjoint solutions are shown to indicate both the optimal location for the source placement and cost gradient. In the particular case of drag reduction by energy deposition, the gradient is proportional to energy efficiency and becomes a key factor in optimization. The general form of the problem makes these results applicable to all forms of volumetric control with the goals of drag reduction, lift enhancement, and the generation of pitching moments.

Adjoint Optimization of Volumetric Sources in Steady, Supersonic Flow: Energy Addition

Modeling of shock propagation in non-uniform gases and plasmas

In weakly ionized plasmas such as those associated with hypersonic flows, Thomson scattering (TS) measurements often suffer from background interference from Rotational Raman scattering (RRS) and plasma luminosity. To overcome this background interference, we propose a new concept, Filtered low-angle Thomson scattering (FLATS), the principle of which is based on the frequency narrowing of the Thomson scattering collected in the forward direction in contrast to the collection angle independent Rotational Raman scattering and plasma luminosity. In this work, we explain the principles of FLATS and present experimental observations of TS and RRS at multiple collecting angles, which confirm the narrowing TS and the frozen RRS at such angles. Additionally, successful spectral separation of TS from background scattering at a low-angle of 22 deg observation, which leads to improved measurement accuracy, is demonstrated. Combined with an atomic vapor prism that can serve as a dispersion-based spectrometer, this technique is expected to enable Thomson measurement in low-temperature, partially ionized plasmas in air/hypersonic environments. 

Demonstration of low angle Thomson scattering for background interference suppression

/pdf/numerical-analysis-and-prediction-of-aero-optical-effects-3hxl8rjowp.pdf

Richard B. Miles

Papers

Sulfur hexafluoride detection by Radar Resonance Enhanced Multiphoton Ionization

Adjoint Optimization of Volumetric Sources in Steady, Supersonic Flow: Energy Addition

Modeling of shock propagation in non-uniform gases and plasmas

Demonstration of low angle Thomson scattering for background interference suppression

Numerical analysis and prediction of Aero-optical effects