Objective: Members of Canonical TRP protein subfamily are non-selective ion channels that can be found in many types of mammalian cells. This study was aimed to elucidate participation of TRPC4 channels in main function of brain neurons that is the action potential (AP) generation. Methods: Using immunocytochemical staining we have identified the expression of TRPC4 in 7-10-day-old cultured neurons derived from lateral septum area of wild-type (WT) mice. No TRPC4 expression was observed in septal neurons from TRPC4-deficient (KO) mice. Single action potentials were evoked by short current pulses in isolated neurons in current-clamp mode. Kinetic characteristics of APs (spike & afterhyperpolarization amplitudes, rise & decay speeds etc.) were calculated. Involvement of TRPC4 channels was evaluated by comparison between WT and TRPC4-/- neurons. Results: Two types of neurons showing different patterns of afterhyperpolarization (AHP) were identified both in WT and TRPC4-/- cultures. Neurons showing fast (approx. 10 ms) and slow (approx. 100 ms) AHP were distributed uniformly and demonstrated no differences in morphology. Statistically significant difference (p<0.05) in parameters of APs generated by WT and TRPC4-deficient cells was found within each group. Absence of TRPC4 lead to increase of both rise & decay speeds of APs observed in neurons with fast AHP (48.9±3.0 mV/ms and -40.4±4.7 mV/ms in WT vs. 64.7±5.6 mV/ms and -63.4±5.7 mV/ms in KO, respectively). By contrast, the rise speed of AP decreased in neurons with slow AHP (-53.4±6.9 mV/ms rise speed in WT vs. -38.2±2.9 mV/ms in KO). Conclusions: On a basis of observed results we conclude that presence of TRPC4 channels in neurons of lateral septum of mice changes the shape of action potentials and thus may have impact on signal transduction through septo-hippocampal pathway and on operation of whole limbic system of the brain.