Abstract
Our previous studies (NeuroReport 12 (2001) 2717) showed that PVG hooded and not Sprague-Dawley (SD) rats exhibit remarkable freezing behavior on exposure to a cat in the cat freezing test apparatus. In the present study, we further examined the differences between these two strains of rats in response to repeated daily exposure to a cat in the cat freezing test apparatus. Freezing behavior habituation was observed in both PVG hooded (days 5-7) and SD rats (days 3-7). A selective CCK 2 agonist (BC264, 0.3 μg/kg, i.p.) on day 8 reversed habituated freezing behavior and locomotor activity in PVG hooded rats, but not in SD rats. These results suggest that CCK 2 receptors mediate habituation to an anxiety-inducing stimulus in PVG hooded rats and further suggest that differential expression of these CCK 2 receptors underlies this strain difference.
Original language | English |
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Pages (from-to) | 205-208 |
Number of pages | 4 |
Journal | Neuroscience Letters |
Volume | 355 |
Issue number | 3 |
DOIs | |
Publication status | Published - 30 Jan 2004 |
Externally published | Yes |
Keywords
- Behavior
- Freezing
- Habituation
- PVG hooded and Sprague-Dawley
- Rats