engleski

Spatial learning and memory in Wistar-Zagreb 5HT rat

Introduction. The serotonin (5-hydroxytryptamine, 5HT) system has been implicated in various aspects of cognitive functions and central 5HT dysregulation contributes to deficits in learning and memory. By use of selective breeding, we have previously developed a rodent model, Wistar-Zagreb 5HT rat, with two sublines constitutionally differing in peripheral (platelet) serotonin level and activity of 5HT transporter. We have further shown that besides in periphery, 5HT homeostasis is also changed in brains of 5HT sublines. In this study, we examined the relationship between altered brain 5HT functioning and cognitive performance in Wistar-Zagreb 5HT rat sublines. Materials & Methods. Males and females from both sublines were tested for spatial learning and memory using Morris water maze task. The device consists of large circular pool with hidden escape platform, just below the water surface. During four days, animals are trained to find the platform using visual cues painted on the walls of the test room. Training consists of two sessions per day (intersession time 90 min), each including three 60 sec trials (intertrial time 15 sec). The time to find the platform is recorded and represents the measure of learning. On the test day (fifth day) the platform is removed from the water and the distance travelled and time spent in the quadrant where the platform was during learning, is recorded by computerized tracking system and represents the measure of memory. Results. In total of eight learning sessions, animals from the high-5HT subline find the platform faster than those from the low-5HT subline. In the memory test, animals from both sublines spent equal time in the quadrant where the platform was previously. Conclusion. This preliminary result shows possible differences in spatial learning abilities between sublines of WZ-5HT rat, confirming the implication of serotonin in formation of spatial, hippocampus-dependent, memory.

spatial learning; Morris water maze; Wistar-Zagreb 5HT-rat

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