Intranasal exposure to manganese disrupts neurotransmitter release from glutamatergic synapses in the central nervous system in vivo

► Acute Mn exposure dose-dependently disrupts odorant-evoked neurotransmitter release from ORNs. ► Direct ORN stimulation revealed pathophysiology occurs downstream of peripheral transduction. ► We found no evidence of histopathology even at Mn doses that suppressed neurotransmission by 90%.