Increasing the number of 5-HT(1A)-receptors in cortex and hippocampus does not induce mnemonic deficits in mice.
Even though the role of the serotonin1A (5-HT(1A))-receptor for cognitive processes is undisputed, the exact involvement of pre- and postsynaptic sites remains unexplained. Recently, we introduced a mouse line overexpressing the 5-HT(1A)-receptor in the hippocampus and cortex. In this study we investigated in comparison to wild-type mice their cognitive abilities using the Morris water-maze task and inhibitory avoidance test. Acute effects of pre- and posttraining administered 8-OH-DPAT (0.03-0.3 mg/kg i.p.) were examined in the inhibitory avoidance test. Additionally, habituation learning was studied in the hole-board test. Transgenic mice showed no overall learning deficit. Spatial learning and memory revealed in the Morris water-maze task was comparable to wild-type mice, and both genotypes habituated to the hole-board arena in a similar manner. Comparing the performance of both genotypes in the inhibitory avoidance test, cognitive functions of transgenic mice seemed to be slightly impaired. When 8-OH-DPAT was administered pretraining an amnesic effect was produced only in transgenic mice and only at the highest dose (0.3 mg/kg). Posttraining administered 0.3 mg/kg 8-OH-DPAT did not affect the performance of both genotypes. Overall, the cortical and hippocampal overexpression of the 5-HT(1A)-receptor had no major effect on cognitive functions in mice, suggesting that changes in the 5-HT(1A)-receptor density are not necessarily accompanied with alterations of learning and memory processes.
Bert
Bettina
B
Institute of Pharmacology and Toxicology, Freie Universität Berlin, Koserstrasse 20, 14195 Berlin, Germany. bert.bettina@vetmed.fu-berlin.de
Voigt
Jörg-Peter
JP
Kusserow
Heike
H
Theuring
Franz
F
Rex
André
A
Fink
Heidrun
H
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D002540:Cerebral Cortex / Q000187:drug effects* / Q000378:metabolism*; D003463:Cues; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008568:Memory / Q000187:drug effects; D008569:Memory Disorders / Q000139:chemically induced* / Q000523:psychology*; D051379:Mice; D008822:Mice, Transgenic; D058825:Serotonin 5-HT1 Receptor Agonists; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D013028:Space Perception / Q000187:drug effects
D058825:Serotonin 5-HT1 Receptor Agonists; D017366:Serotonin Receptor Agonists; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin