Search results
Results from the WOW.Com Content Network
The CTZ has many different types of receptors, which are specific to different types of toxins or drugs that might be present in the bloodstream and thus that can affect the CTZ. Types of CTZ receptors include dopamine, serotonin, histamine, substance P, opioid, and acetylcholine receptors.
Many synthetic and semisynthetic drugs are structural modifications of the alkaloids, which were designed to enhance or change the primary effect of the drug and reduce unwanted side-effects. [208] For example, naloxone , an opioid receptor antagonist , is a derivative of thebaine that is present in opium .
An adrenergic agonist is a drug that stimulates a response from the adrenergic receptors.The five main categories of adrenergic receptors are: α 1, α 2, β 1, β 2, and β 3, although there are more subtypes, and agonists vary in specificity between these receptors, and may be classified respectively.
The hypothesis states that a possible cause of AD is the reduced synthesis of acetylcholine, a neurotransmitter involved in both memory and learning, two important components of AD. Many current drug therapies for AD are centered on the cholinergic hypothesis, although not all have been effective.
Cannabinoid receptor type 1 (CB 1) receptors are thought to be one of the most widely expressed G αi protein-coupled receptors in the brain. One mechanism through which they function is endocannabinoid-mediated depolarization-induced suppression of inhibition , a very common form of retrograde signaling , in which the depolarization of a ...
The binding of a ligand to the receptor causes a conformation change in the receptor. This conformation change can affect the activity of the receptor and result in the production of active second messengers. [citation needed] In the case of G protein-coupled receptors, the conformation change exposes a binding site for a G-protein.
α4β2 nAChRs contain two α4 subunits and three β2 subunits, therefore it has two binding sites for ACh and other agonists. α4β2 nAChRs account for approximately 90% of the nAChRs in the human brain and when chronically exposed to nicotine or other nicotine agonists leads to increase in density of α4β2 receptors which is the opposite of ...
They stimulate cell elongation, breaking and budding, and seedless fruits. Gibberellins cause also seed germination by breaking the seed's dormancy and acting as a chemical messenger. Its hormone binds to a receptor, and calcium activates the protein calmodulin, and the complex binds to DNA, producing an enzyme to stimulate growth in the embryo.