Central effects of corticotropin releasing factor (CRF): evidence for similar interactions with environmental novelty and with caffeine
- 52 Downloads
Centrally administered rat/human corticotropin-releasing factor (rCRF) increases low levels of locomotor activity by rats tested in a familiar environment but suppresses the higher levels of activity associated with exposure of the animals to a novel environment. These opposing responses do not appear to be manifestations of a simple rate-dependent effect, since ICV-administered rCRF did not lower the higher levels of locomotor activity associated with the dark (active) phase of the animal's activity cycle. Caffeine, which has anxiogenic effects in man, produces effects in rats which are similar to those of rCRF. That is, both compounds elevate activity in a familiar environment but lower activity in a novel environment. Furthermore, caffeine appears to substitute for novelty in determining the direction of the locomotor effect of rCRF. Animals made hyperactive by caffeine show decreased activity when co-administered rCRF. These findings are consistent with the view that CRF acts through pathways which also subserve the responsiveness to novelty and to the anxiogenic compound caffeine.
Key wordsCRF Locomotor activity Caffeine Stress Animal models of anxiety
Unable to display preview. Download preview PDF.
- Nemeroff CB, Widerlov E, Bissette G, Walleus H, Karlsson I, Eklund K, Kilts CD, Loosen PT, Vale W (1984) Elevated concentrations of corticotropin-releasing factor-like immunoreactivity in depressed patients. Science 226:1342–1344Google Scholar
- Swerdlow NR, Koob GF (1985) Separate neural substrates of the locomotor activating properties of amphetamine, heroin, caffeine and corticotropin releasing factor (CRF) in the rat. Pharmacol Biochem Behav 23:303–307Google Scholar