| Abstract: | The bioassay of chemical signals in mammals presents a number of problems. Many of these difficulties are the result of the complexity of the behaviour which has to be analysed and of the odiferous output itself. Additionally, it is usual for the response to the odour to be affected by information from other sensory modalities, by experience and by the spatial and social context. This degree of variability and of flexibility which is characteristic of mammals also has the result that concepts such as ‘pheromone’, which were originally developed in simpler organisms, can be seriously misleading. Although valuable information can be gained by less direct methods, a bioassay is only likely to be successful in the identification of active substances if: 1. there is a clearly defined behavioural or physiological response to the odour, 2. the method of testing actually measures this response, 3. the situation used for testing is as close as possible to that in which the response naturally occurs, 4. in the case of a behavioural response, the recording technique is as detailed as possible so that ambiguous results are avoided, 5. an adequate test population is available to allow repeated testing, 6. considerable resources are available for chemical analysis. Although it is not easy to fulfil all of these requirements at one time, olfaction is of such importance in mammalian communication that the attempt to do so will always be valuable. |
