Many factors contribute to dogs' superior olfactory capabilities as compared to humans. Studies explored this aspect at the cellular and behavior levels; however, the cognitive-level neural substrates linking them have never been explored. Since sedated dogs cannot sniff, the present application illustrates the cognitive-level linking neural substrate using fMRI of conscious dogs. The head motion of the canine is accounted for by behavioral training and optical motion tracking. The olfactory bulb is commonly activated in both awake and anesthetized dogs, while parietal and frontal structures are activated only in the former and subcortical structures only in the latter. Comparison of low and high odor intensity shows differences in both the strength and spatial extent of activation in higher cognitive structures. Unlike humans, neural structures even at the top of the cognitive hierarchy are modulated by odor concentration in dogs. This represents one possible mechanism for their superior sense of olfaction as compared to humans.
System and method of functional MRI of the neural system in conscious unrestrained dogs