Cortex: Statistics and Geometry of Neuronal Connectivity

1 Introduction.- 2 Where is the Cortex?.- 3 Analysis of the Neuropil: Preliminary Remarks.- 4 Density of Neurons.- 5 Density of Synapses.- 6 Comparison Between Synaptic and Neuronal Density.- 7 Density of Axons.- 8 Comparison Between the Densities of Neurons, Synapses and Axons.- 9 Microscopic Evidence of the Spacing of Synapses on Axons.- 10 Statistics of the Synapses Along the Axons.- 11 Density of Dendrites.- 12 Different Kinds of Synapses.- 13 Interim Discussion.- 14 Morphology of Neurons: Golgi Pictures.- 15 Classification of Cortical Neurons.- 16 Quantitative Aspects of the Three Types of Neurons. Methods.- 17 Length of the Axonal Ramification of Individual Neurons.- 18 Length of the Dendritic Trees.- 19 Relative Density of Axons and Dendrites.- 20 The Likelihood of a Synapse Between Two Pyramidal Cells.- 21 Peters’ Rule and White’s Exceptions.- 22 Dendritic Spines.- 23 Synapses on Spineless Dendrites.- 24 In Search of Engrams.- 25 Postnatal Changes, Possibly Due to Learning, in the Guinea Pig Cortex.- 26 Cortico-Cortical Connections.- 27 Cortical Architectonics.- 28 Layers.- 29 Cyto- and Myeloarchitectonics: Two Aspects of the Same Reality.- 30 Special Areas.- 31 Map of the Cortex.- 32 How Cortex-Like Is the Hippocampus?.- 33 Summary of Statistical Anatomy and Conclusions Thereof.- 34 Comparative Aspects: Statistical Measures in Larger Brains.- 35 Global Activity, Cell Assemblies and Synfire Chains.- 36 Feature Detectors and Orientation Columns.- 37 Human Language: The Ultimate Challenge for a Theory of the Cortex. An Essay.- References.