Enriched Expression of Serotonin 1B and 2A Receptor Genes in Macaque Visual Cortex and their Bidirectional Modulatory Effects on Neuronal Responses
To study the molecular mechanism how cortical areas are specialized in adult primates, we searched for area-specific genes in macaque monkeys and found striking enrichment of serotonin (5-hydroxytryptamine, 5-HT) 1B receptor mRNA, and to a lesser extent, of 5-HT2A receptor mRNA, in the primary visua...
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Published in | Cerebral cortex (New York, N.Y. 1991) Vol. 19; no. 8; pp. 1915 - 1928 |
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Main Authors | , , , , , , , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
Oxford University Press
01.08.2009
Oxford Publishing Limited (England) |
Subjects | |
Online Access | Get full text |
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Summary: | To study the molecular mechanism how cortical areas are specialized in adult primates, we searched for area-specific genes in macaque monkeys and found striking enrichment of serotonin (5-hydroxytryptamine, 5-HT) 1B receptor mRNA, and to a lesser extent, of 5-HT2A receptor mRNA, in the primary visual area (V1). In situ hybridization analyses revealed that both mRNA species were highly concentrated in the geniculorecipient layers IVA and IVC, where they were coexpressed in the same neurons. Monocular inactivation by tetrodotoxin injection resulted in a strong and rapid (<3 h) downregulation of these mRNAs, suggesting the retinal activity dependency of their expression. Consistent with the high expression level in V1, clear modulatory effects of 5-HT1B and 5-HT2A receptor agonists on the responses of V1 neurons were observed in in vivo electrophysiological experiments. The modulatory effect of the 5-HT1B agonist was dependent on the firing rate of the recorded neurons: The effect tended to be facilitative for neurons with a high firing rate, and suppressive for those with a low firing rate. The 5-HT2A agonist showed opposite effects. These results suggest that this serotonergic system controls the visual response in V1 for optimization of information processing toward the incoming visual inputs. |
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Bibliography: | istex:8E0C31930B43A3A129DDA57CDBEF4913F211EAA2 ark:/67375/HXZ-R45F654R-G Current address: Anatomy and Developmental Neurobiology, Institute of Health Biosciences, University of Tokushima Graduate School, 3-18-15 Kuramotochou, Tokushima 770-8503, Japan. ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Akiya Watakabe, Yusuke Komatsu, and Osamu Sadakane contributed equally to this work. |
ISSN: | 1047-3211 1460-2199 |
DOI: | 10.1093/cercor/bhn219 |