The postnatal development of geniculocortical axon arbors in owl monkeys
| Autor: | S. L. Florence, Marcie W. Pospichal, Jon H. Kaas |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Aging
animal structures Physiology Central nervous system Axonal Transport Slice preparation Parvocellular cell biology.animal medicine Animals Visual Pathways Primate Axon Horseradish Peroxidase Visual Cortex Brain Mapping Developmental stage biology fungi Geniculate Bodies Anatomy Axons Sensory Systems Visual cortex medicine.anatomical_structure nervous system Aotidae Striate cortex Neuroscience Cell Division |
| Zdroj: | Visual Neuroscience. 11:71-90 |
| ISSN: | 1469-8714 0952-5238 |
| DOI: | 10.1017/s0952523800011123 |
| Popis: | To characterize the postnatal development of geniculocortical axon arbor morphology in owl monkeys at a series of ages from birth to adulthood, individual arbors were bulk-filled with HRP in brain slice preparations and were reconstructed from serial sections. At all ages, cortical layers and sublayers were obvious. Presumed M or magnocellular arbors were largely confined to layer IVα, but they also extended into layer IIIc (IVB of Brodmann, 1909); presumed P or parvocellular arbors were almost exclusively confined to layer IVβ. Other axons that may reflect feedback projections from MT terminated in layer IIIc. Overall, M axon arbors increased in size and complexity from birth to adulthood with mean surface-view arbor areas ranging from 0.08 ± 0.01 mm2 in newborns to 0.24 ± 0.02 mm2 in adults. The developing P arbor areas were, on average, as large or larger than adult (newborn = 0.07 ± 0.01 mm2, adult = 0.047 ± 0.01 mm2; n.s.) but the arbors were somewhat less complex. Since the brain and area 17 increase in size postnatally, the proportion of area 17 subserved by each P arbor would decrease in postnatal development. Terminal boutons with immature features were evident in both M and P populations at all developmental ages. The results indicate that, while both LGN axon types in monkeys undergo morphological changes postnatally, M arbors appear to mature by increasing arbor size and terminal branching complexity, whereas P arbors increase in complexity but not in size. These distinct programs of axon arbor development suggest that the periods of susceptibility of geniculocortical axon arbors to postnatal influences of the environment, and the types of plastic responses they potentially exhibit, are class-specific. |
| Databáze: | OpenAIRE |
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