DEFOREST MELLON, JR.
- Professor of Biology
- Email: email@example.com
- Office: (434) 982-5766
- Lab: (434) 982-5766
- Office: 288 Gilmer Hall
- B.S., Yale University, 1957
- Ph.D., The Johns Hopkins University, 1961
- Postdoctoral, Stanford University, 1961-1963
The current focus in our laboratory is to examine the functional competence of chemoreceptor organs based upon their position within an array along the crayfish antennule. Crustaceans exhibit a broad variety of chemoreceptor placement patterns along their antennules. In crayfish, the olfactory receptors, referred to as aesthetascs, are linearly arrayed along the distal half of the antennular lateral flagella. The number of aesthetascs within the array increases with age, but is in a dynamic state of flux: as new aesthetascs are added at the proximal margin of the array at each molt, some older aesthetascs are lost at the distal margin of the array, at the tip of the flagellum. We are interested in the functional consequences resulting from this dynamic regulation of sense organ number. By confining odorant exposure to distinct, well-isolated zones along the array of aesthetascs and measuring the electrical responses of olfactory lobe brain neurons to excitation of olfactory receptor neurons associated with those specific aesthetasc zones, the relative sensitivities of receptors in the different zonal regions can be determined. Our preliminary findings suggest that olfactory receptor neurons within the proximal, nascent zone of the aesthetasc array are significantly more sensitive to standard odorants than those located more distally along the sensor array. Thus, either older olfactory receptor neurons are less sensitive to standard odorants, or older aesthetascs have fewer functionally competent olfactory receptor neurons than younger aesthetascs. These observations indicate possible parallels with the human olfactory mucosa, in which there is a dynamic turnover of olfactory receptor neurons approximately every 30 days.
Mellon, DeF., Reidenbach, M.A. (2011) Fluid Mechanical Problems in Crustacean Active Chemoreception. In Barth, F., Humphrey, J.A.C., Srinivasan, M. (eds) Frontiers in Sensing Springer-Verlag, New York.