Corticotropin-releasing factor (CRF)-induced behaviors are modulated by intravenous administration of teneurin C-terminal associated peptide-1 (TCAP-1).
The teneurin C-terminal associated peptides (TCAP) are a recently discovered family of bioactive peptides that can attenuate aspects of the behavioral stress responses of rats. Because TCAP has some structural similarity to the corticotropin-releasing factor (CRF) family of peptides, and modulates elements of the stress response, TCAP may act to modulate CRF actions in vivo. This hypothesis was tested by investigating anxiety-related behaviors in male rats following repeated intravenous (IV) TCAP-1 administration with either an acute intracerebroventricular (ICV) or IV CRF challenge. TCAP-1 alone did not affect behavioral responses significantly, however did significantly affect CRF-regulated behaviors depending on CRF's mode of injection. In both the elevated plus-maze and the open field tests, TCAP-1 had an anxiolytic effect on ICV CRF responses as indicated by decreased stretched-attend postures in the elevated plus maze (p<0.05), and increased center time and center entries in the open field (p<0.05). However, prior TCAP-1 treatment has an anxiogenic effect on the IV CRF-induced behaviors (decreased center entries and total distance in the open field (p<0.05)). TCAP-1's actions are not mediated through acute changes in glucocorticoid levels and may occur via a central action in the brain. A fluorescently (FITC)-labeled TCAP-1 analog was IV-administered to investigate whether IV TCAP-1 has the potential to regulate central mechanisms by crossing the blood-brain barrier. FITC-TCAP-1 was detected in blood vessels and fibers in the brain indicating that uptake into the brain is a possible route for its interaction with CRF and its receptors. Thus, TCAP may modulate CRF-associated behaviors by a direct action in the CNS.
Al Chawaf
Arij
A
Department of Cell and Systems Biology, University of Toronto, Toronto, Canada. arij.alchawaf@utoronto.ca
Xu
Karen
K
Tan
Laura
L
Vaccarino
Franco J
FJ
Lovejoy
David A
DA
Rotzinger
Susan
S
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001921:Brain / Q000378:metabolism; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology*; D016650:Fluorescein-5-isothiocyanate / Q000378:metabolism; D007276:Injections, Intraventricular; D008297:Male; D018782:Maze Learning; D009419:Nerve Tissue Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D009419:Nerve Tissue Proteins; C500186:TCAP-1 protein, mouse; D003346:Corticotropin-Releasing Hormone; D016650:Fluorescein-5-isothiocyanate