For example, recent work has established quantitative morphological distinctions across different cell types, focusing on quantities such as mean dendritic length, total dendritic length, and number of branching points 4, 5.Īs vast as the structural diversity is, there is an even greater diversity of functional properties 1. Modern techniques and devices have allowed for more precise quantitative measurements at the single-cell level. For instance, Santiago Ramón y Cajal’s “Histology of the Nervous System of Man and Vertebrates” is considered to be the founding document of neurobiology 2, consisting of detailed drawings and comparative descriptive analysis of neuron morphology across different cell types and species 3. Seminal studies in neuroscience characterized morphological differences across cell types. Different types of cells exhibit diverse morphological forms-some neurons have no axons or dendrites, while some have long axon processes that extend over meters, and others have vast dendritic trees that branch extensively to fill two- or three-dimensional space, corresponding to the mathematical and modeling concept known as space-filling 1. The processes form synaptic connections with one another in complex patterns. These dendrites generally conduct signals from the synapse to the cell body. Axons generally conduct signals from the cell body to the synapses, where they connect with the dendrites of other neurons. These processes transfer information between cells in the form of electrical and chemical signals. They are made up of a centralized cell body, called the soma, and two types of extending processes, axons and dendrites. Neurons are fundamental structural units of information processing and communication in animals. Our model also predicts a quarter-power scaling relationship between conduction time delay and body size. Notably, our findings reveal that the branching of axons and peripheral nervous system neurons is mainly determined by time minimization, while dendritic branching is determined by power minimization. We test our predictions for radius scale factors against those extracted from neuronal images, measured for species that range from insects to whales, including data from light and electron microscopy studies. Here, by constructing biophysical theory and testing against empirical measures of branching structure, we develop a general model that establishes a correspondence between neuron structure and function as mediated by principles such as time or power minimization for information processing as well as spatial constraints for forming connections. Classifying neurons according to differences in structure or function is a fundamental part of neuroscience. Neurons are connected by complex branching processes-axons and dendrites-that process information for organisms to respond to their environment.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |