Perceptual constancy for an odour is acquired through changes in primary sensory neurons

Summary The ability to consistently recognise an object despite sensory input that varies with environmental conditions and/or distance from the object is termed perceptual constancy. This is not an innate ability, rather it develops early in life and is likely dependent upon experience ( 1 , 2 ). The neural mechanisms underpinning the development of perceptual constancy are poorly understood. We have taken advantage of the olfactory system of mice and show that when mice are naïve to an odour a perceptual shift occurs with increasing concentration. The perceptual shift coincides with a rapid reduction in activity of a single olfactory receptor channel that is most sensitive to the odour. This drop in activity is not a property of circuit interactions within the olfactory bulb, rather it is due to a sensitivity miss-match of olfactory receptor neurons within the nose. We show that after forming an association of this odour with food, the sensitivity of the receptor channel is matched to the odour object, preventing transmission failure and promoting perceptual stability. These data show that plasticity of the primary sensory organ enables learning of perceptual constancy.