Galanin is a neuropeptide synthesised and released by the brainstem locus coeruleus (LC). Galanin is expressed in most LC neurons in rodents and humans. Galanin has been shown to inhibit LC activity by hyperpolarising LC neurons, suppressing their spontaneous firing rate, and enhancing α2-adrenergic receptor-mediated negative feedback. Galanin is also a potent trophic and neuroprotective factor throughout the nervous system.

Galanin is widely distributed in the central nervous, peripheral, and endocrine systems. Galanin’s overarching function is as an inhibitory, hyper-polarizing neuromodulator for classical neurotransmitters like acetylcholine and serotonin. Galanin interacts with 3 receptor subtypes, GalR1-3 G protein-coupled receptors inserted into the plasma membrane. GalR1 is believed to activate a Gβγ pathway to regulate MAPK activation. GalR2 can also activate the MAPK pathway, but unlike GalR1, there is detectable inositol phosphate production. GalR3 is associated with the Gαi/o pathway. Activation of the receptor leads to a cellular influx of K+. Each receptor has been associated with neurological diseases such as GalR3 and epilepsy.

Galanin protects against various physiological insults in vitro, including excitotoxicity and β-amyloid toxicity. Changes in galanin have been widely studied concerning Alzheimer’s disease, and galaninergic neurons are spared in late-stage Alzheimer’s relative to non-galaninergic neurones.

Galanin is provided here with an N-terminal 5-TAMRA, a widely used red fluorescent reagent ideal for peptide labelling and detection. The excitation/emission for this reagent is 555 nm/580 nm. Cambridge Research Biochemicals is a custom peptide provider. If you desire an alternate dye, please contact us to request a custom synthesis.