Summary Our previous studies have revealed a complex organization of receptive fields (RFs) of neurons in primary somatosensory cortex of monkeys (area 3b). The neurons have small excitatory centers that create the somatotopic map of the hand, a suppressive surround that includes all of the rest of the glabrous hand, and a weaker suppressive surround that includes all of the skin on the other hand (the “extra hand” surround). We propose to determine if neurons in different layers have similar or different surrounds, what surround features are relayed from the thalamus to area 3b neurons, and the connections that mediate different parts of the surround by inactivating cortical areas that directly or indirectly provide feedback to area 3b hand neurons. In addition, we will determine how a major loss of sensory inputs from the hand, due to selective spinal cord lesions, alters the center-surround relationships of neurons in the deprived and non-deprived 3b hand cortex, even after extensive post lesion recovery of 3b reactivation and hand use. The expected results will greatly expand our understanding of how tactile information from the hands is processed in the somatosensory system, and how processing is impaired and recovered following sensory loss. These results will have a clear impact on therapeutic intervention following spinal cord injury.