Dopaminergic modulation of bulbofugal projections in the rat olfactory tubercle

Neuronal activities following olfactory bulb electrical stimulation were examined before and after administration of dopamine and dopamine antagonist in the rat olfactory tubercle. The inhibitory response to olfactory bulb stimulation was attenuated by systemic haloperidol administration, but the excitatory response to olfactory bulb stimulation rarely was modulated. Topical application of dopamine by iontophoresis extended the duration of inhibition in 56% of the neurons sampled and diminished it in 25%; the excitatory response was modulated in 42% of neurons, most of which were attenuated. These findings suggest that dopamine in the olfactory tubercle could be involved in modulations of neuronal activities related to olfactory transduction.