The Journal of Neuroscience, November 15, 2002, 22(22):10046-10052
Diminished Anxiety- and Depression-Related Behaviors in Mice with
Selective Deletion of the Tac1 Gene
Andras
Bilkei-Gorzo,
Ildiko
Racz,
Kerstin
Michel, and
Andreas
Zimmer
Laboratory of Molecular Neurobiology, Department of Psychiatry,
University of Bonn, 53105 Bonn, Germany
The tachykinin neuropeptide substance P and its receptor
neurokinin 1 have been implicated in the regulation of many
physiological and pathological processes, including the control of
emotional behaviors. The present study examines mice with a targeted
deletion of the Tac1 gene, which encodes the
neuropeptides substance P and neurokinin A, in animal models relevant
to depressive illness and anxiety. In depression-related paradigms,
Tac1-deficient mice were more active in the Porsolt's
forced-swimming test and the tail-suspension test, and they did not
become hyperactive after bulbectomy. Tac1 mutant mice
were also less fearful in several animal models of anxiety. They were
more active and less affected by the light conditions in the central
area of the open-field arena; they showed more social interactions in
an aversive environment, they were more active in the open areas of an
elevated zero-maze, and they had a reduced latency to feed in the
Thatcher-Britton conflict paradigm. These results demonstrate that
tachykinins are powerful mediators of depression-like or
anxiety-related behaviors in mice. The tachykinin system therefore may
play an important role in the regulation of emotional states and the
development of anxiety disorders and depression.
Key words:
anxiety; depression; tachykinin; mice; knock-out; stress
Copyright © 2002 Society for Neuroscience 0270-6474/02/222210046-07$05.00/0