Final answer:
Olfactory sensory neurons synapse in the olfactory bulb, where initial processing of olfactory information occurs, bypassing the thalamus which is uncommon for other sensory information.
Step-by-step explanation:
Olfactory sensory neurons, part of the olfactory system responsible for the sense of smell, synapse in the olfactory bulb. Olfactory receptor neurons are located within the olfactory epithelium in the nasal cavity. Their axons project through the cribriform plate of the ethmoid bone and form synapses with the neurons of the olfactory bulb. This structure is where the initial processing of olfactory information occurs. Unlike most sensory pathways which involve the thalamus before reaching the cerebral cortex, the olfactory pathway is unique as it bypasses the thalamus and directly reaches the olfactory cortex from the olfactory bulb.