Original Article

NeuroMolecular Medicine

, Volume 7, Issue 1, pp 157-180

First online:

Galanin and its receptors in neurological disorders

  • Linda LundströmAffiliated withDepartment of Neurochemistry and Neurotoxicology, Stockholm University
  • , Anna ElmquistAffiliated withDepartment of Neurochemistry and Neurotoxicology, Stockholm University
  • , Tamas BartfaiAffiliated withDepartment of Neuropharmacology, The Scripps Research Institute
  • , Ülo LangelAffiliated withDepartment of Neurochemistry and Neurotoxicology, Stockholm University Email author 

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access


Galanin is a highly inducible neuropeptide, showing distinct up-regulation after pathological disturbance within the nervous system. Significant increase in galanin expression is observed after peripheral nerve injury, in the basal forebrain in Alzheimer’s disease (AD), during neuronal development, and after stimulation with estrogen, while seizure activity deplete galanin in the hippocampus. A wide distribution of galanin and its receptors is seen in the nervous system, often in co-localization with classical neurotransmitters and other neuromodulators. Galanin acts predominantly as an inhibitory, hyperpolarizing neuromodulator on neurotransmitter and glucose-induced insulin release and stimulates growth hormone and prolactin secretion. Galanin has been implicated in several higher order physiological functions including cognition, feeding, nociception, mood regulation, and neuroendocrine modulation. The effects of galanin are mediated via three G protein-coupled receptors with different functional coupling. Moderate to low pharmacological effects are seen by galanin under physiological conditions, in contrast to its dramatic effects on the nervous system after neuronal disturbance. This pathophysiological heavy function of the galaninergic system renders it an interest for disorders such as AD, depression, and epilepsy in terms of side effects. Some properties of the galaninergic system are of particular importance in the context of neurodegeneration. Galanin is highly inducible, 10- to 100-fold, upon nerve injury, whereas most neuropeptides are induced 1.5- to 2-fold. Galanin is strongly neurotrophic during development as well as subsequent to injury. Whereas other neurotrophic neuropeptides like VIP and PACAP activate cAMP synthesis, galanin suppresses its synthesis, yet it is a strong neurotrophic as well as neuroprotective agent. As we delineate which galanin receptor subtype mediates neuroprotective and neurotrophic effects and which mediates synaptic inhibition, pharmacological use of receptor-selective galaninergic ligands for treatment in neurodegenerative diseases are coming closer.

Index Entries

Galanin galanin receptors neurodegeneration depression epilepsy Alzheimer’s disease (AD) nerve injury inflammation neurotransmitter neurotrophic factor