Carnosine-induced inward currents in rat olfactory bulb neurons in cultured slices

Olfactory neurons are rich in carnosine, which is regarded as a possible neurotransmitter between olfactory neurons and the olfactory bulb neurons. In the present study, we used the organotypic slice culture technique to culture olfactory bulb neurons and explore carnosine's role in the olfactory system. Inward current responses to carnosine upon increases in membrane conductance were recorded under whole-cell voltage-clamp conditions. The inward currents were desensitized during continuous application of carnosine. At carnosine concentrations above 50 microM, the current responses increased with increases in carnosine concentrations. The present results suggest that carnosine serves as an excitable neuroeffector between olfactory neurons and olfactory bulb neurons.