Читать книгу Neurobiology For Dummies - Frank Amthor - Страница 73

All of the cells in your body have the same lipid bilayer structure for their plasma membrane, but all cells are not the same. What makes a kidney cell or neuron or skin cell all different from each other? Two major differences apply to all the hundreds of distinct cell types in your body:

 Different biochemical reaction sequences: These sequences are particular to specific cell types controlled by selective expression of a subset of the total genes in each cell (although each cell has identical DNA).

 Different protein structures in the plasma membranes: These structures control the flow of ions and other substances through the cell’s membrane.

These two differences are not entirely separate from each other. One of the major functions of the different biochemical reactions going on inside cells is generating and maintaining protein complexes for the cell membrane. All cells, of course, generate the phospholipids to maintain their plasma membranes.

Neurons differ from other cells in your body because they have a large number of specific types of ion channels made of protein complexes specified by a subset of the genes from the DNA in the cell nucleus. Not only do neurons have many more types of these channels than other cells, but many differences exist among neurons because of the hundreds of channel types they express, and the relative numbers of each.