Neural pathways receptors associated with

Redundant component A component which induces a response by interacting with olfactory receptors associated with neural pathways for more potent (primary, secondary, or inhibitory) components. These are not recognized in their own right by the animal s nervous system not required for a mixture to have significant activity but, when present, amplify the activity of other components and thus the mixture. 17a,20p,21P appears to be a redundant component of the goldfish preovulatory steroidal pheromone (see Section 3). 

Single-component pheromone A pheromone which naturally contains either otie component or a closely related set of redundant components which function as a single entity (are encoded by a common neural pathway associated with a single olfactory receptor or set of related receptors). Such compounds are expected to have considerable biological activity regardless of the background odor they might be tested in. However, under certain circumstances (e.g. presence of the odor of a predator see Smith, this volume) their effects may be overridden by the central nervous system in the presence of other stimuli. Their activity should be comparable to the natural odor itself. 

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