after microelectrode recordings identified the locations of the representations of the fingertips along the border of area 3b with area 3a and along the border of area 1 with area 2 , one tracer , tritiated n-acetyl wheatgerm agglutinin ( [ 3h ] wga ) , was injected into the rostral representation at the 3a-3b border , and another , wheatgerm agglutinin conjugated to horseradish peroxidase ( wga : hrp ) , was injected into the caudal representation at the 1-2 border .
C0019941
horseradish peroxidase
C0078473
wga : hrp