Galanin is a neuropeptide present in humans and other mammals. It is a peptide consisting of a chain of 29 amino acids (or 30 amino acids in humans).

Galanin is formed by the cleavage of a prepropeptide encoded by a gene known as GAL. It is involved in a number of physiological processes such as regulation of food intake, metabolism and reproduction, regulation of neurotransmitter and hormone release, nociception, intestinal contraction and secretion, and more recently in nervous system development and response to injury. This wide diversity of action is mediated by several galanin receptor subtypes.

Galanin is predominantly an inhibitory, hyperpolarizing neuropeptide and as such inhibits neurotransmitter release. Galanin is often co-localized with classical neurotransmitters such as acetylcholine, serotonin and norepinephrine and also with other neuromodulators such as Neuropeptide Y, Substance P and Vasoactive intestinal peptide.

Clinical implications

Galanin and its receptor are over expressed in limbic region of the brain in patients suffering from Alzheimer's disease. However it is not clear whether galanin exacerbates or is a protective response to the disease.

References

Further reading

See also

• galanin receptor

External links