Effect of Recurrent Hypoglycemia on Spatial Cognition and Cognitive Metabolism in Normal and Diabetic Rats
Article Figures & Tables
Figures
- FIG. 1.
Alternation performance of animals, both diabetic and nondiabetic. Control animals are those that have not previously been made hypoglycemic; RH animals have been made recurrently hypoglycemic on each of the preceding 3 days. “Euglycemic” and “Hypoglycemic” denote the state of animals at the time of testing. Asterisks indicate significantly different performance levels; groups marked with *, **, or *** are significantly different from control, euglycemic animals, and from each other. See text for full details.
- FIG. 2.
Change in plasma glucose levels in animals tested at euglycemia, throughout testing procedure. No significant intergroup differences were seen. Maze testing period is shown by the light gray box and covers samples 4 and 5.
- FIG. 3.
Hippocampal ECF glucose levels before, during, and after maze testing, marked by light gray box. Asterisks indicate significant differences from baseline for sample 4.
- FIG. 4.
Hippocampal ECF lactate levels, both diabetic and nondiabetic, throughout maze testing (denoted by light gray boxes). Legend applies to both parts of figure.
- FIG. 5.
Response to intraperitoneal glucose bolus (250 mg/kg), given at time of arrows. Main figure shows response of hippocampal ECF glucose in control and RH animals. Asterisk indicates significant intergroup differences for total area under the curve. Inset figure shows plasma glucose response, with same legend; no intergroup difference was seen.
- FIG. 6.
Plasma glucose levels in animals tested at hypoglycemia, throughout testing procedure (light gray box denotes time of testing). Intraperitoneal insulin bolus given to all groups at time of arrow. No significant intergroup differences were seen during or after the maze period.
- FIG. 7.
Hippocampal ECF glucose levels in animals tested at hypoglycemia, throughout testing procedure (marked by light gray box). Intraperitoneal insulin bolus given to all groups at time of arrow. Asterisks mark significant differences between control and RH diabetic groups at times 3 and 4.
Tables
- TABLE 1
Plasma epinephrine (pg/ml)
Basal After maze Euglycemic Nondiabetic Control 58 ± 4 110 ± 20 RH 63 ± 3 142 ± 32 Diabetic Control 51 ± 6 160 ± 28 RH 49 ± 8 124 ± 21 Hypoglycemic Nondiabetic Control 65 ± 5 4,986 ± 539* RH 75 ± 13 1,611 ± 363* Diabetic Control 72 ± 7 3,010 ± 695*‡ RH 83 ± 12 890 ± 293*†‡ Plasma epinephrine concentrations, taken both at baseline (basal) and immediately after completion of maze testing.
- *
* Significant increase in after-maze versus basal samples;
- †
† significant effect of RH (epinephrine decreased versus controls);
- ‡
‡ significant effect of diabetes (epinephrine decreased versus nondiabetics).
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