The use of lectins as a non-invasive approach to the study of odour detection in mammals

Olfaction is one of the most important sensory systems for many mammalian s pecies. Yet, the extent to which olfactory stimuli control the behaviour of a specific species is difficult to establish. Traditionally, massive invas ive techniques like destruction of the olfactory sensory epithelium or bulb ectomy are applied to estimate the effect of olfactory stimuli. However, fo r behavioural research less invasive methods are required. Application of l ectins to the olfactory epithelium seems to be a promising new approach to study the releasing effect of odours on behaviour. This new approach is dem onstrated in 30 adult male Wistar rats for the lectins Concanavalin A, lotu s tetragonolobus and wheat germ agglutinin. Rats were trained to detect low concentrations of ethyl acetate, 1-methyl naphthalene or methacrylic acid. The lectins applied to the olfactory mucosa had selective inhibitory effec ts on odour detection; in each case detection inhibition was reversible wit hin 4-48 h after lectin application. These results provide behavioural evid ence for odour-specific inhibition without destruction to the animal. This new approach is discussed with the traditional invasive techniques use to i nhibit odour detection. (C) 1999 Elsevier Science B.V. All rights reserved.