Fig 2. Effect of cooling on cortex temperature.

[A] Locations of temperature measurements in auditory cortex with a cooling loop (dark shading) held at 10°C. At each site measurements were made at 5 depths, from 500 μm to 2500 μm below the cortical surface, in 500 μm steps. [B] Cortical temperatures at each of the positions in [A] at each depth, symbols indicate the lateral distance of the temperature recording on the cortical surface relative to the cooling loop. The dashed line shows the temperature below which neural firing ceases [5]. Ferret auditory cortex is usually ~1500 μm thick and extends to a maximum of 2000 μm at the thickest part of the gyrus [28].