Developmental vitamin D (DVD) deficiency alters pup-retrieval but not isolation-induced pup ultrasonic vocalizations in the rat.
Evidence from animal experiments now demonstrates that prenatal vitamin D levels influence brain development. The aims of this study were to examine isolation-induced pup ultrasonic vocalizations and maternal-infant interactions using a pup-retrieval test in developmental vitamin D (DVD) deficient and control rats. Sprague-Dawley rats were fed a vitamin D deficient diet or control diet six weeks prior to mating until birth and housed under UVB-free lighting conditions. In two separate experiments we recorded ultrasonic vocalizations at 46KHz in isolated pups and we performed a pup-retrieval test on the day of birth. There was no significant effect of maternal diet on the calling rate of isolation-induced ultrasonic vocalizations by pups. We found that DVD-deficient dams retrieved their pups sooner than control dams and engaged in more pup directed activities (sniffing and carrying pups) and had a longer latency for self-grooming and rearing than control dams. We also assessed vitamin D related measures from a terminal blood sample immediately after the pup-retrieval test and found that DVD-deficient dams and pups had significantly lower levels of 25 OH D₃, 1,25 (OH)₂D₃ and phosphate, elevated levels of parathyroid hormone (PTH) but there was no significant effect of maternal diet on calcium levels. We speculate that the altered maternal-pup interactions identified in the DVD model may impact on early periods of brain development and behaviour.
Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia. t.burne@qcmhr.uq.edu.au
Thomas H J
TH
Burne
Jonathan
J
O'Loan
Karisha
K
Splatt
Suzanne
S
Alexander
John J
JJ
McGrath
Darryl W
DW
Eyles
D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D002658:Developmental Disabilities / Q000209:etiology*; D004195:Disease Models, Animal; D005260:Female; D006887:Hydroxycholecalciferols / Q000097:blood; D011939:Mental Recall / Q000502:physiology*; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D012934:Social Isolation; D013017:Sound Localization / Q000502:physiology*; D018709:Statistics, Nonparametric; D014465:Ultrasonics; D014808:Vitamin D Deficiency / Q000150:complications*
D006887:Hydroxycholecalciferols; C036818:25-hydroxyvitamin D3-26,23-peroxylactone