The effect of systemically administrated cholecystokinin analog, caerulein, on monoaminergic neurons was examined in discrete regions of rat brain. A single injection of caerulein (400 μg/kg, i.p.) significantly elevated 5-hydroxyindoleacetic acid (5HIAA) levels in the prefrontal cortex lateral field, nucleus accumbens, tuberculum olfactorium and striatum after 2 hours, together with a significant increase in striatal serotonin (5HT). Moreover, the time-course study showed that the caerulein-induced increase in both 5HIAA and 5HT levels lasted even for 24 hours, and their levels tended to recover to the control values gradually. This time-dependent change was not found in the other monoamines and their metabolites. These results suggest a long-lasting action of caerulein on 5HT neurons in specific regions of rat brain.
All Science Journal Classification (ASJC) codes
- Endocrine and Autonomic Systems
- Cellular and Molecular Neuroscience