Ion channels are complex proteins that span the cell membrane and form pores through which ions can pass. They can be classified by the type of ion they transport, such as sodium, potassium, calcium, or chloride channels. The structure of these channels includes a pore-forming region and various regulatory domains that control their opening and closing. Histological techniques, such as immunohistochemistry and electron microscopy, are often used to study the distribution and structure of these ion channels within tissues.
