Читать книгу Neurobiology For Dummies - Frank Amthor - Страница 93

The things neurons do — such as receiving, processing, and transmitting information — all require membrane channels that form the following:

 Ion-selective channels: Membrane channels typically allow only certain ions, or groups of ions, to pass through the membrane. These channels may lack gates and, therefore, run continuously, or have gates dependent on the membrane potential or neurotransmitter binding.

 Secretory mechanisms: Membrane structures that use energy or concentration gradients to release substances outside the cell, such as neurotransmitters being released into the space between the pre- and postsynaptic neurons (the synaptic cleft) in a manner similar to how hormones are released into the bloodstream.

 Membrane receptors: Membrane channels called ionotropic receptors can bind neurotransmitters (called ligands) that allow the flow of ions through the membrane. Some receptors, called metabotropic receptors (discussed in more detail in Chapter 4) have the reception and channel functions located in separate protein complexes in the membrane.