Fig. 3.
Bilateral nanoinjections of (2R)-amino-5-phosphonovalericacid (AP5)/6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) into dorsomedial hypothalamus (DMH) reverse the increases in brown adipose tissue (BAT) sympathetic nerve activity (SNA), BAT temperature (TBAT), expired carbon dioxide (Exp CO2), and heart rate (HR) evoked by decreasing temperature of the preoptic area (TPOA). A: representative example of the effect of AP5/CNQX injections into DMH (indicated by 2 vertical dashed lines; bilateral injections: R, right side and L, left side) on the recorded parameters during preoptic area (POA) cooling. B: group data (mean ± SE, n = 5) for the time course of the responses to AP5/CNQX or saline vehicle injections into DMH, during preoptic area (POA) cooling. Each time point represents 30 s averages. *P < 0.05, significant difference between the value at the 5th minute of cooling vs. the control precooling value, for both the AP5/CNQX trial and the vehicle trial. #P < 0.05, significant difference between the AP5/CNQX induced change from the cooling-induced peak vs. the change from the cooling-induced peak following vehicle; ns, not significant. Ci: photomicrograph of a representative nanoinjection site in the DMH (arrow indicates blue bead deposits). Cii: a schematic plot of the injection sites in the DMH (blue circles) on a coronal section at approximately −3.0 to −3.3 mm caudal to bregma. AP, arterial pressure. f, fornix.