title: Somatosensory cortex of the neonatal pig: II. Topographic organization of the secondary somatosensory cortex (SII).
abstract: Multiunit microelectrode recording techniques were used to delineate the somatotopic organization of the secondary somatosensory cortex (SII) of the neonatal pig. Barbiturate anesthetized piglets ranging in age from 7 days preterm to 2 months postpartum were used. The SII area, located lateral to the rostral and middle suprasylvian sulci, was found to contain a complete somatotopic representation of the contralateral body surface with a significant proportion of bilateral input for all body regions except the forehoof and forelimb. The SII forelimb and hindlimb representations were found to possess a "striplike" orientation in a rostral to caudal sequence, and the trunk representation was located posterolateral to the hindlimb representation, giving SII an inverted appearance. Two apparently separate face representations were delineated; one posterolateral to the projection from the trunk and the other anterior to the forehoof region. Unlike SI, which possesses a disproportionately large representation of the rostrum, SII has no specialized representation of the rostrum. The overall organization of SII supports the contention that this cortical region provides a more generalized representation of the entire body surface than does SI.
authors.affiliation: Department of Physiology, East Carolina University, Greenville, North Carolina 27858-4354.
authors.forename: S L
authors.initials: SL
authors.lastname: Craner
authors.forename: R H
authors.initials: RH
authors.lastname: Ray
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001931:Brain Mapping; D005145:Face / Q000502:physiology; D005552:Forelimb / Q000502:physiology; D006614:Hindlimb / Q000502:physiology; D008839:Microelectrodes; D009434:Neural Pathways / Q000502:physiology; D013003:Somatosensory Cortex / Q000033:anatomy & histology* / Q000502:physiology; D013909:Thorax / Q000502:physiology