What are the chemical messengers in the brain that can either excite or inhibit receptors called?

Neurotransmitters are the chemical messengers in the brain responsible for transmitting signals across synapses between neurons. They play a crucial role in regulating a wide range of functions, including mood, sleep, cognition, and pain perception. When released by a neuron, neurotransmitters bind to specific receptors on the surface of adjacent neurons, which can result in either an excitatory or inhibitory effect on the receiving cell.

Excitatory neurotransmitters, such as glutamate, promote the firing of neurons, enhancing communication, while inhibitory neurotransmitters, like gamma-aminobutyric acid (GABA), dampen neuronal activity, reducing the likelihood of a firing response. This complex balance between excitation and inhibition is essential for maintaining normal brain function and is a key element in neurochemical signaling.

Hormones, while also important chemical messengers, primarily function within the endocrine system rather than directly affecting neuronal communication in the brain. Neurons are the cells that transmit signals but are not classified as chemical messengers themselves. Proteins serve various functions within the body, including helping with cellular structure and function, but they are not directly involved in signaling as neurotransmitters are. Thus, the specific role of neurotransmitters as the mediators of communication