Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.


Logo for

PNAS 102 (48): 17489-17494

Copyright © 2005 by the National Academy of Sciences.

From The Cover


Anxiolytic- and antidepressant-like profiles of the galanin-3 receptor (Gal3) antagonists SNAP 37889 and SNAP 398299

Chad J. Swanson *, {dagger}, Thomas P. Blackburn * {ddagger}, Xuexiang Zhang *, Kang Zheng §, Zhi-Qing David Xu §, Tomas Hökfelt §, ¶, Toni D. Wolinsky *, Michael J. Konkel *, Heidi Chen *, Huailing Zhong *, Mary W. Walker *, Douglas A. Craig *, Christophe P. G. Gerald *, and Theresa A. Branchek *

*Lundbeck Research USA, Inc., Paramus, NJ 07652-1431; and §Department of Clinical Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden

Contributed by Tomas Hökfelt, October 13, 2005

Abstract: The neuropeptide galanin mediates its effects through the receptor subtypes Gal1, Gal2, and Gal3 and has been implicated in anxiety- and depression-related behaviors. Nevertheless, the receptor subtypes relevant to these behaviors are not known because of the lack of available galanin-selective ligands. In this article, we use behavioral, neurochemical, and electrophysiological approaches to investigate the anxiolytic- and antidepressant-like effects of two potent small-molecule, Gal3-selective antagonists, SNAP 37889 and the more soluble analog SNAP 398299. Acute administration of SNAP 37889 or SNAP 398299 enhanced rat social interaction. Furthermore, acute SNAP 37889 was also shown to reduce guinea pig vocalizations after maternal separation, to attenuate stress-induced hyperthermia in mice, to increase punished drinking in rats, and to decrease immobility and increase swimming time during forced swim tests with rats. Moreover, SNAP 37889 increased the social interaction time after 14 days of treatment and maintained its antidepressant effects during forced swim tests with rats after 21 days of treatment. In microdialysis studies, SNAP 37889 partially antagonized the galanin-evoked reduction in hippocampal serotonin (5-hydroxytryptamine, 5-HT), as did the 5-HT1A receptor antagonist WAY100635. Their combination produced a complete reversal of the effect of galanin. SNAP 398299 partially reversed the galanin-evoked inhibition of dorsal raphe cell firing and galanin-evoked hyperpolarizing currents. These results indicate that Gal3-selective antagonists produce anxiolytic- and antidepressant-like effects, possibly by attenuating the inhibitory influence of galanin on 5-HT transmission at the level of the dorsal raphe nucleus.

Key Words: anxiety • depression • galanin • neuropeptide • dorsal raphe

Conflict of interest statement: No conflicts declared.

Freely available online through the PNAS open access option.

Abbreviations: DRN, dorsal raphe nucleus; SSRI, selective serotonin reuptake inhibitor; CDP, chlordiazepoxide; 5-HT, serotonin (5-hydroxytryptamine); FST, forced swim test; vHip, ventral hippocampus; p.o., oral(ly) (per os); i.c.v., intracerebroventricular(ly).

{ddagger} Present address: Helicon Therapeutics, Inc., Farmingdale, NY 11735.

{dagger} To whom correspondence may be addressed at: Target Discovery and Assessment, Department of Mechanistic Studies, Lundbeck Research USA, Inc., 215 College Road, Paramus, NJ 07652. E-mail: chjs{at}

To whom correspondence may be addressed. E-mail: tomas.hokfelt{at}

© 2005 by The National Academy of Sciences of the USA

Distinct features of neurotransmitter systems in the human brain with focus on the galanin system in locus coeruleus and dorsal raphe.
E. Le Maitre, S. S. Barde, M. Palkovits, R. Diaz-Heijtz, and T. G. M. Hokfelt (2013)
PNAS 110, E536-E545
   Abstract »    Full Text »    PDF »
Involvement of galanin receptors 1 and 2 in the modulation of mouse vagal afferent mechanosensitivity.
A. J. Page, J. A. Slattery, S. M. Brierley, A. S. Jacoby, and L. A. Blackshaw (2007)
J. Physiol. 583, 675-684
   Abstract »    Full Text »    PDF »

To Advertise     Find Products

Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882