Neurochemical changes in the developing rat hippocampus during prolonged hypoglycemia

Abstract

This report reviews laryngoplastic techniques for correction of bowing of the vocal cords, with special consideration to the anatomic details of the anterior commissure. I present a new technique in which the glottic gap is closed by bilateral medialization. This technique may be superior to those described previously, since the correction achieved at the time of surgery is maintained by the placement of Silastic

Region-Specific Cerebral Metabolic Alterations in Streptozotocin-Induced Type 1 Diabetic Rats: An in vivo Proton Magnetic Resonance Spectroscopy Study

“…37 Insulin injection to the STZ-treated animals caused significant decreases of the Glu level in the striatum at 4 days, and in the striatum and hippocampus at 4 weeks ( Figure 5). Previous studies have demonstrated reduced Glu level in the brain of nondiabetic rats 14 and T1DM patients 38 after insulin injection. It has been suggested that the mechanism underlying these observations is likely related to the fact that the brain can use Glu as an alternative substrate for energy metabolism in response to insulininduced hypoglycemia.…”

“…It has been suggested that the mechanism underlying these observations is likely related to the fact that the brain can use Glu as an alternative substrate for energy metabolism in response to insulininduced hypoglycemia. 14,38 It is interesting to note that insulin-induced reductions of Glu level at 4 weeks were observed in the absence of severe hypoglycemia. In the model of STZ-induced T1DM with uncontrolled blood glucose level, the brain appears to be in a hypermetabolic state, and uses greater amounts of energy substrate than normal.…”

“…The absolute concentrations of Cr and PCr may be sensitive to blood glucose level in normal nondiabetic rats and STZ-treated T1DM rat, but the absolute concentration of tCr is rather stable under such circumstances. 9,14,25 Absolute tCr concentration was also measured by in vivo 1 H-MRS in the basal ganglia, frontal lobe, temporal lobe, GM-rich occipital lobe, thalamus, posterior frontal WM, and WM-rich parieto-occipital region of clinical T1DM patients, and none of these studies reported any significant changes in the tCr level. 2,3,5,6 One previous study showed that absolute hyperglycemia tCr level in the hippocampus of STZ-treated rats were~10% higher than control at 30 days after induction.…”

Changes in Human Brain Glutamate Concentration during Hypoglycemia: Insights into Cerebral Adaptations in Hypoglycemia-Associated Autonomic Failure in Type 1 Diabetes

“…15,17,18 Studies in rats demonstrated that during the transition to an isoelectric electroencephalogram (EEG) in the setting of hypoglycemic coma reductions in Glu, glutamine (Gln) and Lac levels are accompanied by an increase in aspartate (Asp) before a precipitous drop in the phosphocreatine-to-creatine (PCr/Cr) ratio indicative of energy failure. [18][19][20][21] Whether similar changes also occur in the human brain is unknown.…”

“…This approach encompassed the reliable quantification of a neurochemical profile of several metabolites including Lac, Asp, and Gln, which have been observed to change upon severe hypoglycemia in the rat brain. [18][19][20][21] Hence, the changes in the levels of these additional neurochemicals were investigated in an exploratory fashion.…”