Characterization of neural network reorganized by peripheral deafferentation in SI cortex and VPL thalamus of anesthetized rats

Abstract

Partial blocking of a sensorγ transmission from the periphery to the central nervous system by amputation. cold block and local anesthesia induces immediate somatotopical reorganization at multiple levels of the somatosensorγ system of adult mammals. The emergence of new receptive field (RF) or expansion of RF to RF boundary (RFB) after temporary deafferentation (TD) by local anesthesia has been suggested to be mediated with synaptic correlation among neurons. In this study, we characterized the alteration of neural network among neurons in each area during TD. TD induced the suppression of excitatorγ postsynaptic activities triggered by RF center (RFC) neurons，while those by RFB and RF outside (RFO) neurons in both SI cortex and VPL thalamus increased during TD. The quantification of neuronal activities changed during TD strongly suggests that the reorganization in SI cortex is more conspicuous than that in VPL thalamus. This means that TD-induced suppression of RFC activities may primarily lead the facilitation of RFB and RFO neurons, functionally disinhibiting the lateral inhibition among neurons.