As a subject matter expert in cellular biology, I can explain the concept of cell polarization. Cell polarization is a process where cells develop distinct regions or compartments with specific functions. This is a crucial aspect of cell differentiation and is particularly important in multicellular organisms where cells often need to communicate with each other or perform specialized tasks. In the context of cell biology, "polarized" cells have a non-uniform distribution of proteins, lipids, and other molecules across their plasma membrane. This asymmetry allows the cell to orient its functions and interactions with its environment. For example, in epithelial cells, which line the surfaces of internal organs and external body surfaces, one side of the cell is in contact with the external environment, while the other side is in contact with the internal environment. This polarity allows the cells to perform different functions on each side, such as absorbing nutrients on one side and secreting waste on the other. read more >>

The cell membrane separates the inside of a cell (all cells, not just neurons) from the outside, and all chemicals that get into and out of the cell must go thorough it. As in all cells, the cell membrane of a neuron is polarized. This means that there is an electrical difference across the cell membrane.read more >>