Deprivation-related and use-dependent plasticity go hand in hand

Abstract

Arm-amputation involves two powerful drivers for brain plasticity—sensory deprivation and altered use. However, research has largely focused on sensory deprivation and maladaptive change. Here we show that adaptive patterns of limb usage after amputation drive cortical plasticity. We report that individuals with congenital or acquired limb-absence vary in whether they preferentially use their intact hand or residual arm in daily activities. Using fMRI, we show that the deprived sensorimotor cortex is employed by whichever limb individuals are over-using. Individuals from either group that rely more on their intact hands (and report less frequent residual arm usage) showed increased intact hand representation in the deprived cortex, and increased white matter fractional anisotropy underlying the deprived cortex, irrespective of the age at which deprivation occurred. Our results demonstrate how experience-driven plasticity in the human brain can transcend boundaries that have been thought to limit reorganisation after sensory deprivation in adults.DOI: http://dx.doi.org/10.7554/eLife.01273.001

Representation of Multiple Body Parts in the Missing-Hand Territory of Congenital One-Handers

“…The putative missing-hand ROI was defined by mirror-flipping the intact/dominant-hand ROI on the x axis [1, 2] (see Supplemental Experimental Procedures for validation of this ROI). ROIs of the arm and lip (in the deprived/nondominant hemisphere) and foot (bilaterally) were defined using a similar procedure.…”

Neuroimaging mechanisms in pain: from discovery to translation

“…However, the underlying principle behind this theory and the efficacy of behavioral therapies targeting this reorganisation have been revisited in a series of recent studies using different paradigms and performed by our group and others. [76][77][78][79] Rather than loss of sensory input being characterized by structural and functional degeneration in the deprived sensorimotor cortex, we found that the experience of persistent pain was associated with preserved structure and functional organization in the former hand area if the patients are asked to "move their missing limb" rather than imagine movement-good news for the patient and suggesting that despite often decades of missing input, the cortical region is functionally normal and capable of activity. However, consistent with the isolated nature of phantom experience, phantom pain is associated with reduced interregional functional connectivity in the primary sensorimotor cortex.…”

Remodeling of cortical activity for motor control following upper limb loss

“…Research has shown that use of the amputated limb in daily living correlates to plasticity in the “deprived cortex” (Makin et al, 2013). Thus, if the amputated limb is not used regularly in daily living, this could affect plasticity.…”