Patterning of the neocortical projections from the raphe nuclei in perinatal rats: investigation of potential organizational mechanisms.

摘要: Serotoninergic (5-HT), fibers in the cerebral cortex of perinatal rats have a pattern that coincides with boundaries primary sensory areas and within somatosensorycortex form rattunculus. This patterned immunoreactivity (IR) appears about 60 hours after birth disappears between postnatal days (P-) 12 15. Three experiments were carried out to evaluate mechanisms might underlie precise patterning 5-HT-IR. Retrograde labelling fluorescent tracers revealed only coarse rostrocaudal ography raphe-cortical projection existence raphe cells projecting multiple cortical locations. Thus, point-to-point, does not 5-HT-IR. Ablation thalamus prior age at which 5-HT-IR could be seen developing caused complete loss immunoreactivity. suggests 5-HT may require presence thalamocortical axons achieve observed normal animals. Serotoninergic neurons transplanted cortices newborn exhiwited extensive axonal outgrowth, but did somatotopic pattern. result also specific spatiotemporal interactions growing necessary for former fibers. © 1994 Wiley-Liss, Inc.