Food and Behaviour Research

Donate Log In

Adult vitamin D deficiency disrupts hippocampal-dependent learning and structural brain connectivity in BALB/c mice

Al-Amin MM1, Sullivan RKP, Kurniawan ND, Burne THJ (2019) Brain Struct Funct.  2019 Feb.  doi: 10.1007/s00429-019-01840-w. [Epub ahead of print] 

Web URL: Read this and related abstracts on PubMed here

Abstract:

Converging evidence from human and animal studies support an association between vitamin D deficiency and cognitive impairment. Previous studies have shown that hippocampal volume is reduced in adults with vitamin D deficiency as well as in a range of disorders, such as schizophrenia.

The aim of the current study was to examine the effect of 
adult vitamin D (AVD) deficiency on hippocampal-dependentspatial learning, and hippocampal volume and connectivity in healthy adult mice. Ten-week-old male BALB/c mice were fed a control (vitaminD 1500 IU/kg) or vitamin D-depleted (vitamin D 0 IU/kg) diet for a minimum of 10 weeks. The mice were then tested for hippocampal-dependent spatial learning using active place avoidance (APA) and on tests of muscle and motor coordination (rotarod and grip strength). The mice were perfused and brains collected to acquire ex vivo structural and diffusion-weighted images using a 16.4 T MRI scanner. We also performed immunohistochemistry to quantify perineuronal nets (PNNs) and parvalbumin (PV) interneurons in various brain regions. AVD-deficient mice had a lower latency to enter the shock zone on APA, compared to control mice, suggesting impaired hippocampal-dependent spatial learning.

There were no differences in rotarod or grip strength, indicating that AVD 
deficiency did not have an impact on muscle or motor coordination. AVD deficiency did not have an impact on hippocampal volume. However, AVD-deficient mice displayed a disrupted network centred on the right hippocampus with abnormal connectomes among 29 nodes. We found a reduction in PNN positive cells, but no change in PV, centred on the hippocampus.

Our results provide compelling evidence to show that AVD 
deficiency in otherwise healthy adult mice may play a key role in hippocampal-dependent learning and memory formation. We suggest that the spatial learningdeficits could be due to the disruption of right hippocampal structural connectivity.

FAB RESEARCH COMMENT:

See the associated news article: