In vivo fMRI demonstration of hypothalamic function following intraperitoneal glucose administration in a rat model

The hypothalamic functional MRI (fMRI) response in an animal model was stud ied following energy intake. Six fasted (12 h) Sprague-Dawley (SD) rats wer e administered an intraperitoneal injection of glucose (0.72 grams/kg body weight), while a mid-sagittal slice through the hypothalamus was continuous ly imaged for 60 min using a conventional T-2*-weighted gradient-echo seque nce. All rats demonstrated a significant acute transient decrease in the fM RI signal intensity (mean: 3.4%) in the hypothalamic region within 12-16 mi n after intraperitoneal glucose injection. The SD rat may be a suitable mod el for future fMRI studies of the hypothalamus involving the administration of exogenous nutrients and medications. Magn Reson Med 43:155-159, 2000, ( C) 2000 Wiley-Liss, Inc.