Facilitatory effect of substance P on learning and memory in the inhibitory avoidance test for goldfish.

The aim of this study was to investigate if substance P (SP) can improve learning and memory processes in goldfish, using an inhibitory avoidance test. A two-compartment aquarium with a central sliding door was used. The animals were placed in the white compartment, and after 20 s the door was opened. As they entered the dark compartment, a weight was dropped in front of them. This procedure was repeated three times. After training, the animals were injected intraperitoneally with SP or vehicle. Twenty-four hours after training, the animals were tested and their latency was recorded. The group injected with SP showed an increase in the latency on the test day as compared with the vehicle group. These results suggest SP can facilitate memory in goldfish in an inhibitory avoidance test.