Which one of the following does not act as a neurotransmitter?

Cortisone a steroid, a drug that lowers inflammation is a corticosteroid is a pro-hormone that must be reduced to cortisol in order to bind to and activate the glucocorticoid receptor. It promotes the synthesis and storage of glucose and is important in the normal response to stress, suppresses inflammation and regulates deposition of fat in the body. Acetylcholine, epinephrine and norepinephrine are neurotransmitters. Related Theory Neurotransmitters are often referred to as the body's chemical messengers. They are the molecules used by the nervous system to transmit messages between neurons, or from neurons to muscles. Communication between two neurons happens in the synaptic cleft. Here, electrical signals that have travelled along the axon are briefly converted into chemical ones through the release of neurotransmitters, causing a specific response in the receiving neuron.