Have you ever wondered how cells communicate with other cells? How can one cell tell the entire organism what to do next?
Cell signals and produced from a sending cell. In order for a cell to detect a signal, a surrounding cell must have a receptor on the cell's surface to respond to the signal. Once a signal molecule, called a ligand, binds to the cell's receptor, the molecule is able to alter either the shape or activity of the receptor, thus altering the cell. The ligand carries a message to its intended cell. Once the ligand attaches to the receptor, there is a relay of chemical reactions within the cells, called intracellular reactions.
There are a variety of cell signaling reactions. Synaptic signaling is where nerve cells send signals to other nerve cells. Firstly, an electric impulse travels down the axon of the neuron, causing the membrane to depolarize and allow calcium ions to flow inside. The neuron sending the signal or the presynaptic neuron releases neurotransmitters into synapse. The neurotransmitters then bind to the receptors of the postsynaptic cell. Synaptic signaling is vital to the nervous system and more specifically cognitive processing.
Some reactions are not as easy as just sending a signal to the surrounding cells (Paracrine signaling).
Endocrine signaling is where cells transmit signals over long distances; the opposite of Paracrine signaling. Signals, produced by cells, are sent into the bloodstream, which then carries them away to their target cells. Hormones are signals that are created in one part of the body and are transported through the bloodstream to varying locations.
From sending signals to far away cells to sending them to neighbors, cell signaling is a fascinating biological process that is unfortunately too often overlooked. These processes of cell signaling are vital for organisms to maintain healthy states and adapt to their surroundings.
Works Cited:
Introduction to cell signaling (article) | Khan Academy. (n.d.). Khan Academy. https://www.khanacademy.org/science/ap-biology/cell-communication-and-cell-cycle/cell-communication/a/introduction-to-cell-signaling#:~:text=Cells%20typically%20communicate%20using%20chemical,bottle%20%E2%80%93%20over%20to%20neighboring%20cells.
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