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Virtual Science Fair

Group Information | Project Abstract
Nervous System | Neurons | Ion Channels | Action Potentials | Synapses
Purpose | Hypothesis
Results | Conclusion
Results | Conclusion
Results | Video 1 | Video 2 |Conclusion
Discussion | Credits

Ion Channels

The nerve cell has a overall negative charge, when different chemicals; particularly ions move through the membrane; the polarity changes. The cell's resting potential is about -70 mV. The diagram below illustrates the various relative concentrations (in mols) of ions within the cellular environment. Ion channels within the cellular membrane allow for the passage of ions in and out of the cell. As chemicals move around, the charge of the cell changes.

For example, an decrease in potassium ion concentration within the cell, will result in depolarization of the cell, that is; the charge of the cell increases from -70, to a more positive state. A decrease in sodium ion concentration within the cell will result in the hyperpolarization of a cell, meaning that the charge of the cell decreases (this is usually only initiated after a depolarization; as will be seen in action potentials). These changes in cell polarity are crucial for the development and occurrence of action potentials; which are the core of synapses.