Motion-induced alterations in 2-deoxyglucose uptake in brainstem nuclei of squirrel monkeys: autoradiographic and liquid scintillation studies.

Abstract

Each of 8 young adult female squirrel monkeys were injected via a femoral vein cannula with 167 microCi/100 g body weight of 2-(1,2-3H)-deoxy-D-glucose (2-DG) (New England Nuclear, 37.3 Ci/mmol) in 0.5 ml sterile saline. 4 additional female squirrel monkeys were injected in the same manner with 100 microCi/100 g body weight of the (3H)-2-DG. 2 h after this initial injection the original 8 animals were injected with 16.7 microCi/100 g body weight of 2-(1-14C)-deoxy-D-glucose (51.3 mCi/mmol) in 0.5 ml sterile saline. The 4 additional animals were injected with 25 microCi/100 g body weight of the (14C)-2-DG. Half of the animals each dose level were restrained in the upright position with Velcro straps and a nontraumatic moulded plastic head holder on a modified animal restraint board [Withrow and Devine, 1972] with the head in the sagittal plane but tilted forward about 20 degrees. They were then subjected to horizontal rotary motion at 25 rpm together with a vertical movement of 6 inches at 0.5 Hz for 1 h in a lighted room. The other half of the animals at each dose were restrained in the same manner and maintained in a quiescent state. At the end of this period each animal was anesthetized with ketamine, and the brain was quickly dissected out and frozen in isopentane cooled to -60 degrees C with dry ice. Transverse cryostat sections (-15 degrees C) of the brainstem were cut alternately at 200 and 20 microns from the nucleus gracilis caudally through the superior vestibular nucleus rostrally. Micropunch samples of the individual vestibular nuclei, and other brainstem nuclei and areas were obtained from the 200-microns sections with a modification of the method of Eik-Nes and Brizzee with a small stainless steel punch measuring 850 microns in diameter. The frozen punch samples were prepared for liquid scintillation counting (Beckman LS7500 system). Differential (3H) and (14C) counts (cpm) were made employing external standards. The 20-microns sections were prepared for 14C autoradiography by standard methods employing Kodak SB-5 X-ray film. The (14C) autoradiographs from the motion-stimulated animals revealed a selectively high uptake of 2-DG in all of the vestibular nuclei, the lateral cuneate nucleus and the lateral reticular nucleus as compared with the corresponding structures in the control animals.(ABSTRACT TRUNCATED AT 400 WORDS)