Effects of Aging and <i>D</i>-Glucose on Locomotor Activity, Spontaneous Alternation, and Plasma Glucose Levels in Preweanling Sprague-Dawley Rats

Abstract

Previous research has shown that developmentally related memory impairments in immature rodents are malleable and may be attenuated using a variety of pharmacological and behavioral treatments. This experiment examined the effects of glucose (10, 100, 250 or 500 mg/kg) or saline on blood glucose level, locomotor activity, and spontaneous alternation (SA) in the T-maze. Studies were conducted with 20-, 22-, and 24-day-old preweanling Sprague-Dawley rats. Results indicated a general decline in blood glucose level with age and size of glucose injection. The largest overall decline in blood glucose was found following the 500 mg/kg dose in 24-day-old animals. An increase in T-maze arm entries with age indicated increased exploratory activity. SA generally improved with age, but glucose had no reliable effect on behavior. The ontogenetic state of the nervous system, including changes in cholinergic system activity, glucoregulation, and proliferation of glucose transporters, is discussed.

Epinephrine‐induced enhancement of memory retrieval for inhibitory avoidance conditioning in preweanling Sprague–Dawley rats

“…Animals at this stage of development are also undergoing a major switch from the use of ketones to glucose as the primary energy source (Vannucci & Simpson, 2003). In a recent study, 20-, 22-, and 24-day-old animals showed a decrease in blood glucose levels with age following 5 min in a T-maze (Flint, Papandrea, & Dorr, 2006). Glucose injections in that study produced evidence of a corresponding increase in glucoregulatory response with age.…”