Hyperlocomotion associated with transient prenatal vitamin D deficiency is ameliorated by acute restraint.

Transient prenatal vitamin D deficiency produces hyperlocomotion in the adult rat. The aim of this study was to examine the effects of acute restraint on the behaviour of DVD and control rats in the open field. Rats were conceived and born to developmentally vitamin D (DVD) deficient or replete (control) dams and, at 8 weeks of age, were monitored for 30 min in an open field using automated video tracking software. Half of the rats were restrained within a towel for 5 min immediately before the open field test. The remainder received minimal handling prior to the open field test. Repeating previous findings, DVD deficient animals had enhanced locomotion during the first 10 min of the open field test compared to control rats. By contrast, there were no differences in locomotor activity after acute restraint stress. The time rats spent in the corners and side of the open field was affected by prenatal diet. DVD rats spent less time in the corners and more time in the side than control rats across the whole 30 min test. This difference was not seen in rats with acute restraint stress. The time spent in the centre was not altered by prenatal diet or acute restraint. Thus, transient prenatal vitamin D deficiency induces a transient spontaneous hyperlocomotion in adulthood that is modulated by acute restraint stress.