The relationship between the activity of individual neurons and behavior is a core interest of neurobiology. Extracellular recording and stimulation techniques and have demonstrated that single neuron activity of neurons is closely correlated with behavior in mammals, but both techniques are not suited to pinpoint the impact of single neuron activity on behavior. We confront this problem by stimulating single neurons in the rat vibrissal system and testing the effect on vibrissal movement and sensation. This approach reverses conventional physiological research, where APs are mainly studied as correlates of sensorimotor processing. Specifically we addressed this issue by assessing effects of single cell stimulation in (i) the vibrissal motor cortex (ii) the vibrissal motor neurons in the facial nucleus, (iii) in the somatosensory cortex of awake rats. In vibrissa motor cortex we find that AP initiation in individual cells causes long sequences of small and slow multi whisker movements. AP number had only little effect on whisker movement amplitude but it strongly affected movement latency. AP frequency in contrast did not affect movement latency but determined movement amplitude and direction. In the facial nucleus we find that AP initiation in individual cells causes mainly but not exclusively single whisker movements. Movements are brief and usually fast and each spike causes a very similar fixed latency movement. Thus, motor cortical neurons and cells in the facial nucleus code movements in very different ways: Cortical APs affect movements on long time scales and APs are read as sequences or “words”, such that the effect (movement latency and direction) of an AP depends on the AP context. In contrast, facial nucleus APs are translated spike by spike to movement twitches. We also investigated sensory effects of single cell stimulation in the somatosensory cortex. To this end animals were first trained to report trains of cortical microstimulation pulses by a tongue lick. Once the animal reported small microstimulation currents, microstimulation trials were mixed with trials in which we evoked ~ 14 APs in single cortical neurons. Rats responded significantly more often after single cell stimulation than in catch trials without stimulation. The bias introduced by single cell stimulation was weak on average but could be strong for individual cells. We conclude that the activity of single sensory cortical neurons can lead to a behaviorally reportable effect. Thus, single neuron stimulation in general and the parametric variation of initiated AP patterns in particular, allow us to decode (i.e. measure effects of APs and AP train parameters) single neuron activity in an unprecedented fashion.