Windows 10: What is the $WINDOWS.~BT folder used for? This folder is used by the Windows 10 Updater, it contains update logs and files downloaded by the Windows update process. How to delete the $WINDOWS.~BT folder? The folder can be deleted e.g. when an upgrade from windows 7 / 8 to Windows 10 failed and you want to free up space on the hard disk.
Two Types of Receptors. There are two types of acetylcholine receptors (AChR) that bind acetylcholine and transmit its signal: muscarinic AChRs and nicotinic AChRs, which are named after the agonists muscarine and nicotine, respectively.
Nicotinic acetylcholine receptors are ligand-gated ion channels permeable to sodium, potassium, and calcium ions. In other words, they are ion channels embedded in cell membranes, capable of switching from a closed to open state when acetylcholine binds to them; in the open state they allow ions to pass through.