Functionally Independent Columns of Rat Somatosensory Barrel Cortex Revealed with Voltage-Sensitive Dye Imaging

摘要: Whisker movement is somatotopically represented in rodent neocortex by electrical activity clearly defined barrels, which can be visualized living brain slices. The functional architecture of this part the cortex thus mapped vitro with respect to its physiological input and compared anatomical architecture. spatial extent excitation was measured at high temporal resolution imaging optical signals from voltage-sensitive dye evoked stimulation individual barrels layer 4. correlated closely subthreshold EPSPs recorded simultaneously excitatory neurons 4 2/3, respectively. Excitation initially ( 3 msec) spread a columnar manner into 2/3 then subsided both layers after approximately 50 msec. lateral response limited cortical column structurally barrel Two experimental interventions increased excitation. First, blocking GABA(A) receptor-mediated synaptic inhibition caused laterally throughout wide regions 5 but not neighboring suggesting that local connections within are restricted single inhibitory control supragranular infragranular layers. Second, NMDA receptor-dependent increase induced pairing repetitive coincident column. Such plasticity could underlie changes map structure alterations sensory experience.