How is the brain informed that a receptor is adapting to a stimulus?

When the receiver is adapting to a stimulus, the receiver decreases its polarization. This causes a decrease in frequencies that travel to the brain, informing the brain that the receptor is in the process of adapting.

Explanation:

Each neurotransmitter is programmed to respond to certain stimuli. To do so, they are endowed with receptors that recognize signaling molecules and send rapid responses to the brain. These molecules can be proteins, amino acids, hormones and various other substances. The moment it receives a stimulus, the receptors undergo a rapid adaptation period, at which point the receptor decreases its depolarization. This causes the frequency of signals that this receptor sends to the brain to be decreased, signaling to the brain that adaptation is taking place.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.