Plasticity in primary somatosensory cortex resulting from environmentally enriched stimulation and sensory discrimination training

• ELIANA GUIC ^[1] ; XIMENA CARRASCO ^[2] ; EUGENIO RODRÍGUEZ ^[1] ; IGNACIO ROBLES ^[3] ; MICHAEL M MERZENICH ^[4]
  1. [1] Pontificia Universidad Católica de Chile

     Pontificia Universidad Católica de Chile

     Santiago, Chile

     
  2. [2] Universidad de Chile

     Universidad de Chile

     Santiago, Chile

     
  3. [3] Universidad de Chile School of Medicine Department of Surgery Hospital del Salvador
  4. [4] UCSF Keck Center for Integrative Neurosciences

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• Localización: Biological Research, ISSN-e 0717-6287, ISSN 0716-9760, Vol. 41, Nº. 4, 2008, págs. 425-437
• Idioma: inglés
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• Resumen

  • We studied primary-somatosensory cortical plasticity due to selective stimulation of the sensory periphery by two procedures of active exploration in adult rats. Subjects, left with only three adjacent whiskers, were trained in a roughness discrimination task or maintained in a tactile enriched environment. Either training or enrichment produced 3-fold increases in the barrel cortex áreas of behaviorally-engaged whisker representations, in their zones of overlap. While the overall áreas of representation expanded dramatically, the domains of exclusive principal whisker responses were virtually identical in enriched vs normal rats and were significantly smaller than either group in roughness discrimination-trained rats. When animáis were trained or exposed to enriched environments with the three whiskers arrayed in an are or row, very equivalent overlaps in representations were recorded across their greatly-enlarged whisker representation zones. This equivalence in distortion in these behavioral preparations is in contradistinction to the normal rat, where overlap is strongly biased only along rows, probably reflecting the establishment of different relations with the neighboring cortical columns. Overall, plasticity phenomena are argued to be consistent with the predictions of competitive Hebbian network plasticity.