As the effects of ultrasound on human brain functions might bear therapeutic potential, in this study, we examined the effects of diagnostic, i.e. non-thermal, ultrasound, on morphology, networking, and metabolic activity of SH- SY5Y human neurons in culture, as well as on the expression of GAP-43, Hsp90 and VEGF proteins, with and without selenium in the culture medium. The rationale for studying selenium lays in the observation that selenium improves functional neurologic outcome in traumatic brain injury and, therefore, analysis of the interactions between ultrasound and selenium may be of clinical interest. In the presence of selenium, ultrasound increased the overall number and length of elongations arising from the neuron bodies, thus reflecting an increase in the complexity of neuronal networks and circuits. The expression of GAP-43, Hsp90 and VEGF and metabolic activity of SH-SY5Y neurons, studied as markers of cell damage, were not affected by ultrasound or selenium. This study suggests that ultrasound may modulate neuronal networking in vitro without inducing cellular or molecular damage and highlights the potential role of selenium in the ultrasound-elicited cellular responses.