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Explore the intricate world of neurons and their transmission in this informative article. Discover the historical perspective, different types of neurons, and the electro-chemical processes behind neuronal communication.
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The Neuron is the Fundamental “working unit” of the nervous system
But is different in that it can produce electrical impulses near its cell body region
That move down the axon and lead to the release of specialized neurochemicals (neurotransmitter substances) at the Synapse
Synaptic release of Neurotransmitter substances may in turn affect “postsynaptic” neurons; mostly in the dendritic regions
Historical perspective:The “Reticular Theory • The nervous system was thought to be a continuous network of fibers…no individual cells
There are many types of neurons:Some common types of neurons
The Neuron is also different in that the axon is typically myelinated by “glial cells”
There are many types of glial cells: all are thought to primarily provide support functions
The Neuronal communication process can be thought of as an “electro-chemical” event • How is the electric signal produced? • How is the Chemical event produced?
Ions are responsible for the charge of a neuron Cations + Anions-
At Rest, ionic substances have different concentrations inside vs. outside the neural membrane
Hyperpolarization and Depolarization • Hyperpolarization- makes the RMP more negative • Depolarization-makes the RMP more positive
If ion channels are open; diffusion across concentration and electrostatic gradients will occur
Triggering the release of RMP energy • How does threshold depolarization trigger a dynamic response? • Changes membrane permeability • Activating/opening ion channels • -”Voltage-gated” Na+ ion channels • Open only when a critical level of depol occurs • Other ion channels then become involved