Effects of maternal mild zinc deficiency and different ways of zinc supplementation for offspring
on learning and memory
Sammanfattning
Background: The effect of different ways of zinc supplementation on spatial learning and
memory remains unclear.
Objectives: This study aims to assess the effectiveness of two ways of zinc supplementation - oral
use and intravenous transfusion - in zinc-deficient offspring rats on learning and memory.
Design: Rats were randomly divided into six groups on the first day of pregnancy (n=12): control (CO),
pair fed (PF), zinc deprived (ZD), oral zinc supplementation (OZS), injection zinc supplementation
(IZS), and injection control. The offspring’s spatial learning and memory were tested at postnatal day
35 using Morris water maze (MWM). Maternal rats’ serum zinc was measured at postnatal day 21,
while pups’ serum zinc was measured at postnatal day 35.
Results: Compared with the CO and PF groups, pups in ZD group spent more time finding the latent
platform and swam longer distances (p<0.05). Compared with ZD groups, pups in OZS group
significantly decreased the time used for finding the platform and the swimming distance (p<0.05)
and were similar to that of CO and PF groups (p>0.05). However, compared with ZD groups, pups in
IZS did not show any improvement in the indexes of MWM (p>0.05) although their zinc serum
concentration increased significantly (p<0.05).
Conclusions: These results indicate that mild zinc deficiency during pregnancy and lactation leads to
the impairment of learning and memory function in offspring, and that OZS, instead of intravenous
transfusion zinc supplementation, can recover the impairment of spatial learning and memory
function.