Anxiety-like behavior in weanling and young adult male and female malnourished rats

Abstract

The present study determined whether protein-calorie malnutrition alters anxiety-like behavior in weanling and young adult, male and female malnourished rats. On the day of birth, litters of Wistar rats were divided into Control (C) and Malnutrition (M) groups. In the C group, litters were fed by dams receiving ad libitum lab chow, whereas in the M group, litters were fed by dams receiving 40% of the total amount of the diet offered to dams in the C group. After weaning (PND21) until PND50, animals received the same food as theirs mothers (i.e., ad libitum access in the C group and 40% of the C group food in the M group). On PND21 and PND50, independent C (male [CM] and female [CF]) and M (male [MM] and female [MF]) groups were exposed to the elevated T-maze. The time taken to withdraw four paws from this arm was recorded (baseline latency [BL]). The same measurement was repeated twice at 30s intervals (avoidance trial 1 [AT1] and avoidance 2 [AT2]). The cutoff time in each trial was 300s. ANOVA indicated a four-way age×diet×sex×trials interaction. Post hoc comparisons revealed that PND50 rats had a lower BL and AT1 latency compared with PND21 rats. Training increased both AT1 and AT2 latencies compared with BL in both the CM and CF groups. Weanling malnourished rats exhibited reduced anxiety-like behavior and young adult male rats presented less anxiety-like behavior than young adult female rats in this experimental model.