ODOR DISCRIMINATION OF IP3 AND CAMP-INCREASING ODORANTS IN THE TURTLEOLFACTORY-BULB

The ability of the turtle olfactory system to discriminate between var ious odorants that increase levels of adenosine 3',5'-cyclic monophosp hate (cAMP) and inositol trisphosphate (IP3) in the olfactory bulb was examined by the cross-adaptation technique and analyzed by multidimen sional scaling. The mean values of the degree of discrimination among the IP3-increasing odorants were higher than those among the cAMP-incr easing odorants, and were similar to those between cAMP- and IP3-incre asing odorants, suggesting that the features of the receptors of cAMP- increasing odorants are different from those which respond to IP3-incr easing odorants. Analysis by multidimensional scaling suggested that d ifferences in second messenger pathways are not related to detecting o dor quality in the turtle olfactory system.