Developmental Learning in a Pain-Related System: Evidence for a Cross-Modality Mechanism

摘要: The nociceptive spinal reflex system performs highly precise sensorimotor transformations that require functionally specified synaptic strengths. specification is gradually attained during early development and appears to be learning dependent. Here we determine the time course of this for heat-nociceptive tail withdrawal reflexes analyze which types primary afferents are important by applying various forms noninvasive sensory deprivations. percentage erroneous (i.e., movements directed toward stimulation) decreased from 64.1 +/- 2.5% (mean SEM) <10% postnatal days 10-21. This improvement was completely blocked anesthetizing adaptation period, confirming an experience-dependent mechanism involved in However, results show occurs a significant extent despite local analgesia protection noxious input, provided tactile sensitivity preserved. Therefore, it input not necessary adaptation, receptors can used guide organization development. Sensory deprivation adult rat failed affect system, indicating has "critical period" These findings provide key puzzle how pain-related systems adapted through experience rare occurrence life.