Cells from olfactory bulbs of embryonic rats were grown in dissociated cell culture for up to 5 weeks. Both neurons and non-neuronal cells grew in these cultures, with a variety of neuronal populations appearing. A population of 20-25% of the neurons were GABAergic by the criterion of [3H]GABA uptake. Electrophysiologic measurements were made of the baseline activity of the cultured neurons. Cells showed a mean resting potential of 60.1 +/- 1.2 mV and a mean input resistance of 87.6 +/- 9.5 M omega. All cells were sensitive to microperfusion of GABA with half-maximal effect occurring at about 20 microM. Glutamate was universally excitatory but with variations in degree. Carnosine (beta-Ala-L-His), tested over the concentration range of 10 nM to 100 microM, had no effect on input resistance, resting potential, action potential shape, on-going synaptic activity or the responsiveness to either GABA or glutamate. These results are further evidence against a role for carnosine as the excitatory transmitter of the primary olfactory afferents.