Processing of vibrissa sensory information within the rat neocortex.

摘要: Neuronal response properties were compared among different layers of the urethan-anesthetized rat vibrissa cortex. Measurements made receptive-field (RF) size, degree directional selectivity, latency driving, velocity threshold, and tuning-curve slope. The RF size was defined by number whiskers that, when deflected individually, activated a neurons. For center whisker (usually C3), to deflection in most preferred direction with that opposite classify neuron as either strongly directional, weakly or nondirectional. whisker, minimum required drive unit driven standard supramaximal measured, finally, using exponential ramp-and-hold deflection, threshold amplitude determined at values time constant construct Cortical layer IV neurons, whole, have lowest velocity. Layer Vb neurons stand on extreme having highest mean value. Although this difference is consistent generally held view "barrels" represent input stage cortical information processing, lack laminar differences support idea other also receive direct thalamocortical inputs. population thus appears quite homogeneous across far results examination short-pulsed stimulation are concerned. Correlation pairs parameters (RF, directionality, latency) tested two (layer Vb). highly correlated within both layers. Also, correlation coefficients corresponding similar. However, use revealed slope between (also II-III); show flatter slopes (more oriented for detection component deflection) than II-III, which more detection. During hold phase tend sustained discharges, whereas II-III) mainly exhibit transient responses.(ABSTRACT TRUNCATED AT 400 WORDS)