Local Cortical Circuits: An Electrophysiological Study

ISBN-13: 9783642817106 / Angielski / Miękka / 2011 / 104 str.

Moshe Abeles

Opis

Neurophysiologists are often accused by colleagues in the physical sci ences of designing experiments without any underlying hypothesis. This impression is attributable to the ease of getting lost in the ever-increasing sea of professional publications which do not state explicitly the ultimate goal of the research. On the other hand, many of the explicit models for brain function in the past were so far removed from experimental reality that they had very little impact on further research. It seems that one needs much intimate experience with the real nerv-. ous system before a reasonable model can be suggested. It would have been impossible for Copernicus to suggest his model of the solar system without the detailed observations and tabulations of star and planet motion accu mulated by the preceeding generations. This need for intimate experience with the nervous system before daring to put forward some hypothesis about its mechanism of action is especially apparent when theorizing about cerebral cortex function. There is widespread agreement that processing of information in the cor tex is associated with complex spatio-temporal patterns of activity. Yet the vast majority of experimental work is based on single neuron recordings or on recordings made with gross electrodes to which tens of thousands of neurons contribute in an unknown fashion. Although these experiments have taught us a great deal about the organization and function of the cor tex, they have not enabled us to examine the spatio-temporal organization of neuronal activity in any detail."

Spis treści

1 Introduction.- 2 Techniques.- 2.1 Single-Unit Recording.- 2.2 Multi-Unit Analysis.- 2.3 Limitations of Our Recordings Technique.- 2.4 Analysis of Spike Trains by Renewal Density.- 3 The Spontaneous Firing of Cortical Neurons.- 3.1 Patterns of Firing.- 3.2 Neural Mechanisms.- 3.3 Membrane Potential, Threshold, and Excitability.- 3.4 Sources of Excitatory Inputs.- 4 Interactions Between Pairs of Cells.- 4.1 Cross-Renewal Density.- 4.2 Types of Cross Renewal Densities.- 4.3 Synaptic Relations Between Adjacent Neurons.- 4.4 Sources of Excitation Within Groups of Neurons.- 4.5 Is the Cortical Network Randomly Connected?.- 5 Responses to Sound.- 5.1 Stating the Problem.- 5.2 Responses of Groups of Neurons to Sound.- 5.3 Stability of the Cortical Network.- 5.4 Is the Auditory Cortex a Purely Sensory Station?.- 6 Spatio-Temporal Patterns of Activity.- 6.1 Compound Renewal Densities.- 6.2 How Three Cells Interact.- 7 Transmission of Information by Coincidence.- 7.1 The Single Neuron as a Coincidence Detector.- 7.2 Existence of Chains of Neuronal Sets with Appropriate Connections.- 7.3 Some Properties of Synfire Chains.- 8 Organization of Generators of the ECoG.- 8.1 The Generation of the ECoG.- 8.2 Population Statistics and ECoG.- 8.3 Experimental Results.- 9 Information Codes for Higher Brain Function.- 9.1 Hypotheses.- 9.2 Experimental Evidence.- 10 Conclusion.- References.