Fig. 2. A typical example of a change of receptive field (RF) size in response to halothane is shown. The RF was mapped on the skin of the hindquarter. One MAC of halothane significantly decreased the RF size to 3.5 cm2from the control value of 13.2 cm2. With discontinuation of halothane inhalation, the RF recovered to the control value (13.4 cm2).