Chemosensory capacities

Later in intra-uterine life, the human infant is susceptible to early chemical prompting, but again the affector route is not known with certainty. Neonatal discrimination in favour of familiar (maternal) amniotic fluid is demonstrable, suggesting that the foetus already has active chemosensory capacities (Schaal, 1998). Smell and taste are operative in the near full-term foetus since it shows detection of about 120 mg/day maternal intake of anethole (as anise condiments) within a few days before parturition this exposure induced subsequent preferential responses by babies to anethole (Schaal et ai, 2000). The human neonate is not likely to have its organ as a fully functioning chemosensor,... 

The best possible outcome of a bioassay is the elicitation of a specific behavior pattern by a defined chemical stimulus (Miiller-Schwarze 1977). This chapter presents methods to assess the role of chemical stimuli in the behavior of birds and mammals. An overview of the chemosensory capacities of birds and mammals to perceive stimuli is provided first, followed by a description of test paradigms that can be incorporated into bioassays. The preponderance of the chapter describes examples of these paradigms incorporated into bioassays to assess the role of chemical signals in inter- and intra-specific behaviors. The examples, like past studies in mammalian and avian chemical ecology, are disproportionately represented by rodents. Most of the described procedures, however, could be modified for other species, provided the apparatuses and the response variables can be altered to accommodate the different subject and stimuli. 

Rodentia (4/30) Of the 2000 or so species, none is suspected of loss. Even a highly fossorial form, the murine Mole Rat, maintains an AOS capacity (Heth, 1995 Zuri, 1998). A promising candidate, the subterranean and eusocial Naked Mole Rat (Batherygidae), shows little or no chemosensory contribution to reproductive regulation (Lacey, 1991 Faulkes et al., 1993). The role of its AOS remains to be discovered, possibly the outbreeding (dispersive) morph is the best candidate type (O Riain et al., 1996). 

Rehorek S.J., Firth B.T. and Hutchinson M.N. (2000). The structure of the nasal chemosensory system in squamate reptiles, 2 Lubricatory capacity of the vomeronasal organ. J Biosci 25, 181-190. 

Olfaction is very much present and influential in our everyday life and its day-to-day quality [1]. For instance, it has been shown by Delwiche [2] that taste and smell are rated as being the most important sensations in flavor. Thus, olfaction is the key to our relationship with food and in particular plays a major role in identifying it [3]. That is why significant changes in chemosensory perception have the capacity of interacting with aroma perception, diet selection, and to some extent nutritional status [4]. 

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