In the majority of neurons (78.5%; 22/28), the background (“spontaneous”) activity was <1 spike/s (Figures 2A,C). Before PTV inactivation, the mean background activities of simple and complex cells were almost identical (mean: 0.78 spikes/s vs. 0.72 spikes/s; see Table 1). There was some reduction in the background activities of both simple (mean: 0.48 spikes/s) and complex (mean: 0.44 spikes/s) cells during PTV inactivation. However, only in a couple of cells (2/28; 7%—1 simple, 1 complex), the background activities during PTV inactivation were significantly lower than those before inactivation (Figure 2C). The mean background activities after rewarming PTV were lower but not significantly different from those before cooling (Table 1).