A neurochemical is a small organic molecule or peptide that participates in neural activity. The science of neurochemistry studies the functions of neurochemicals.
Glutamate is the most common neurotransmitter. Most neurons secrete with glutamate or GABA. Glutamate is excitatory, meaning that the release of glutamate by one cell usually causes adjacent cells to fire an action potential. (Note: Glutamate is chemically identical to the MSG commonly used to flavor food.)
GABA is an example of an inhibitory neurotransmitter.
Dopamine is a monoamine neurotransmitter. It plays a key role in the functioning of the limbic system, which is involved in emotional function and control. It also is involved in cognitive processes associated with movement, arousal, executive function, body temperature regulation, and pleasure and reward, and other processes.
Norepinephrine, also known as noradrenaline, is a monoamine neurotransmitter that is involved in arousal, pain perception, executive function, body temperature regulation, and other processes.
Serotonin is a monoamine neurotransmitter that plays a regulatory role in mood, sleep, appetite, body temperature regulation, and other processes.
Histamine is a monoamine neurotransmitter that is involved in arousal, pain, body temperature regulation, and appetite.
Trace amines act as neuromodulators in monoamine neurons via binding to TAAR1.
Acetylcholine assists motor function and is involved in memory.
Nitric oxide functions as a neurotransmitter, despite being a gas. It is not grouped with the other neurotransmitters because it is not released in the same way.
Endocannabinoids act in the endocannabinoid system to control neurotransmitter release in a host of neuronal tissues, including the hippocampus, amygdala, basal ganglia, and cerebellum.
Eicosanoids act as neuromodulators via the Arachidonic acid cascade.[1]
Neuropeptides
Orexins (-A and -B) are involved in a number of cognitive processes, including appetite, arousal, and reward, among many others.
^Piomelli, Daniele (2000). "Arachidonic Acid". Neuropsychopharmacology: The Fifth Generation of Progress. Retrieved 2006-03-03.
^"Neurotrophic factors". Nature Publishing Group. Retrieved 31 May 2016. Neurotrophic factors are molecules that enhance the growth and survival potential of neurons. They play important roles in both development, where they can act as guidance cues for developing neurons, and in the mature nervous system, where they are involved in neuronal survival, synaptic plasticity and the formation of long-lasting memories.
^Malenka RC, Nestler EJ, Hyman SE (2009). "Chapter 8: Atypical Neurotransmitters". In Sydor A, Brown RY (eds.). Molecular Neuropharmacology: A Foundation for Clinical Neuroscience (2nd ed.). New York: McGraw-Hill Medical. pp. 199, 215. ISBN9780071481274. Neurotrophic factors are polypeptides or small proteins that support the growth, differentiation, and survival of neurons. They produce their effects by activation of tyrosine kinases.
^Zigmond MJ, Cameron JL, Hoffer BJ, Smeyne RJ (2012). "Neurorestoration by physical exercise: moving forward". Parkinsonism Relat. Disord. 18 Suppl 1: S147–50. doi:10.1016/S1353-8020(11)70046-3. PMID22166417. As will be discussed below, exercise stimulates the expression of several neurotrophic factors (NTFs).