An mRNA expression analysis of stimulation and blockade of 5-HT7 receptors during memory consolidation.
Despite the compelling support for 5-hydroxytryptamine (5-HT) receptors participation in learning and memory in mammal species, the molecular basis had been largely absent from any discussion of its mechanistic underpinnings. Here, we report that reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed that there was a higher level of expression of the investigated 5-HT receptor mRNAs in autoshaping-trained relative to untrained groups. Actually, pharmacological naïve untrained and autoshaping-trained rats showed significant differences, the latter groups expressing, in decreasing order, 5-HT1A < 5-HT6 < 5-HT4 < or = 5-HT7 receptors mRNA in prefrontal cortex and hippocampus. In order to determine more precisely mRNA expression and memory consolidation, we combined selective 5-HT7 receptors stimulation or blockade in the same animals, and brain areas individually analyzed. 5-HT7 receptors were strongly expressed in all the three brain areas of vehicle-trained rats relative to untrained group. The potential selective 5-HT7 receptor agonist AS 19 enhanced memory consolidation, attenuated mRNA receptors expression, and the facilitatory memory effect was reversed by SB-269970. Finally, pharmacological stimulation of 5-HT7 receptors reversed scopolamine- or dizocilpine-induced amnesia and receptor down-regulation.
Depto. de Farmacobiología, CINVESTAV, Mexico City, Mexico.
Georgina
G
Pérez-García
Claudia
C
Gonzalez-Espinosa
Alfredo
A
Meneses
D000818:Animals; D001245:Association Learning / Q000187:drug effects / Q000502:physiology; D003214:Conditioning, Classical / Q000187:drug effects / Q000502:physiology*; D005786:Gene Expression Regulation; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008568:Memory / Q000187:drug effects / Q000502:physiology; D017397:Prefrontal Cortex / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D011903:Raphe Nuclei / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018490:Serotonin Agents / Q000494:pharmacology
D012333:RNA, Messenger; D011985:Receptors, Serotonin; D018490:Serotonin Agents; C104425:serotonin 7 receptor