Brain Research, 196 (1980) 43-58 43 © Elsevier/North-Holland Biomedical Press THE EFFECT OF UNILATERAL BASILAR PAPILLA REMOVAL UPON NUCLEI LAMINARIS AND MAGNOCELLULARIS OF THE CHICK EXAMINED WITH [aH]2-DEOXY-D-GLUCOSE AUTORADIOGRAPHY* WILLIAM R. LIPPE, OSWALD STEWARD and EDWIN W. RUBEL** Departments of Otolaryngology, Neurosurgery and Physiology, University of Virginia Medical Center, Box 430, Charlottesville, Va. 22908 (U.S.A.) (Accepted February 28th, 1980) Key words: 2-deoxy-o-glucose- - n. laminaris - - n. magnocellularis - - deafferentation - - auditory system SUMMARY The effect of unilateral basilar papilla removal on glucose uptake in the 2nd and 3rd order auditory nuclei in the chick's brain stem, nucleus magnocellularis and nucleus laminaris, respectively, was examined with [3H]2-deoxy-D-glucose (2-DG) autoradiography. The tissue was processed according to a thaw-mount technique, and the number of grains in the resulting autoradiographs was counted to assess changes in glucose uptake. It was observed that there is a greater density of grains over the neuropil regions of nucleus laminaris which receive input from the normal ear than over the corresponding regions which receive input from the operated ear. Similarly, differences in grain density are found between the normally innervated and deaffer- ented magnocellular nuclei although these differences are not as great as those in nucleus laminaris. Differences in grain density were also apparent between the glial/fiber regions which bound the neuropil areas of nucleus laminaris; there is a greater density of grains overlying those glial/fiber regions through which fibers receiving input from the normal ear course than over those regions through which fibers which normally carry input from the operated ear travel. It is likely that this difference mainly reflects glucose uptake in the fibers although a possible contribution of glial tissue cannot be excluded. All these effects of basilar papilla removal are seen with survival times as short as 70 min and thus likely reflect the reduction of neural activity rather than the degeneration of pre- or postsynaptic elements. Finally, * A preliminary account of this study was presented at the 92nd Sessionof the American Association of Anatomists, 1979. ** To whom correspondence should be addressed.