Stimulus evoked neuronal activity depends on ongoing activity (Arieli et al. Science, 1996, Petersen et al. PNAS 2003) and spontaneous neuronal activity can resemble stimulus specific activations patterns (Kenet et al.Nature, 2003).This suggests that neuronal activity within one functional domain or column is coordinated. Here we ask if neighboring neurons fire action potentials (APs) during cell specific patterns of electrical neuronal network activity. Supra-threshold events were recorded with tetrodes (yielding on average 4.4 units) in Urethane anesthetized rats (p 28 to p 35). Simultaneously sub-threshold electrical population activity was measured using the voltage sensitive dye RH 1691 during spontaneous and whisker evoked activity in the barrel cortex. Spatio-temporal heterogeneous spontaneous activity (up- and down states) occurred in all of the recordings. Spatial patterns averaged around the occurrence of APs differed between units. Spatial patterns at the occurrence of APs of the same unit varied substantially. However spatial patterns during APs of the same unit could be more similar amongst each other compared to spatial patterns during APs of different units. This supports the hypothesis that individual neurons within the same functional column can be part of separate neuronal subgroups during spontaneous network activity.