Olfaction in Rats with Transection of the Lateral Olfactory Tract

Abstract

The lateral olfactory tract (LOT) is the major, although not the only, projection pathway from the olfactory bulb to the anterior olfactory nucleus and olfactory cortex. Transection of the LOT produces deficits in the ability to smell. However, some reports indicate that rats or hamsters with LOT transection are anosmic or have severe olfactory deficits (Cattarelli, 1982; Devor, 1973; Long and Tapp, 1970; Marques, O’Connell, Benimoff, and Macrides, 1982; Thompson, 1980) while others (Gervais and Pager, 1982; Slotnick, 1985; Slotnick, 1990; Slotnick and Berman, 1980; Slotnick and Risser, 1990; Swann, 1934) indicate much less severe deficits after similar lesions. Except for a few studies (Bennett, 1968; Slotnick and Schoonover, 1984), most prior investigations of neuroanatomical correlates of olfactory function have not used quantitative olfactometric methods or psychophysical tests and it is difficult to compare or evaluate their outcomes. This problem is addressed in the present study by assessing odor detection, two-odor discrimination, intensity-difference and absolute detection thresholds of rats in which the lateral olfactory tract was transected.