Plasticity of 5-hydroxytryptamine sub(1B) receptors during postnatal development in the rat visual cortex

• Published in: International journal of developmental neuroscience Vol. 17; no. 4; pp. 305 - 315
• Main Authors: Ruiz, G, Bancila, M, Valenzuela, M, Daval, G, Kia, KH, Verge, D
• Format: Journal Article
• Language: English
• Published: 01-07-1999
• ISSN: 0736-5748
• DOI: 10.1016/S0736-5748(99)00039-8

The distribution of 5-hydroxytryptamine sub(1A) and 5-hydroxytryptamine sub(1B) receptors in the visual cortex was studied by quantitative autoradiography during postnatal development. Overall, receptor densities increased throughout development, but exhibited regional rearrangements, particularly in the case of 5-hydroxytryptamine sub(1B) receptors. Neonatal treatment with 5,7-dihydroxytryptamine, which causes selective degeneration of serotoninergic neurons, had no effect on the density of 5-hydroxytryptamine sub(1A) receptors in the visual cortex. However, a transient increase in 5-hydroxytryptamine sub(1B) at postnatal days 10-12 was observed after this treatment, suggesting a regulation of postsynaptic receptors. Neonatal enucleation resulted in a marked increase in 5-hydroxytryptamine sub(1B) binding sites in all layers of the visual cortex by P16, whereas it had no effect upon 5-hydroxytryptamine sub(1A) binding sites. These results show that both receptor subtypes do not exhibit striking transient features in the visual cortex during postnatal development, but rather undergo discrete reorganizations. 5-Hydroxytryptamine sub(1B) receptors show changes in density after either neonatal degeneration of serotoninergic neurons or enucleation, indicating that the serotoninergic system involving this receptor subtype can exhibit some postnatal plasticity in the visual cortex.