Zienab Alrefaie
Scientific Tracks Abstracts: J Neurol Neurophysiol
Complications of diabetes mellitus include cognitive impairments and functional changes in the brain. The present study
aimed to investigate the possible beneficial effect of vitamin D3 on episodic memory and cholinergic transmission in the
prefrontal cortex of streptozotocin-induced diabetic rats.
Methods: 30 male Wistar rats (150-200 gm) were included into control, diabetic and diabetic supplemented with vitamin D3
groups. Diabetes was induced by single intraperitoneal injection of streptozotocin (stz) 45mg/kg in citrate buffer. Vitamin D3
was administered orally in a dose of 500 IU/kg/day in corn oil for 10 weeks. Then rats were subjected to novel object recognition
test to examine for episodic memory. Animals were sacrificed under diethyl ether anesthesia and prefrontal cortices were
dissected to measure the activity of choline acetyl transferase (CAT) and acetyle choline esterase (ACE) enzymes to assess for
cholinergic transmission.
Results: Diabetic rats spent significantly less time exploring the novel object compared to control animals. Vitamin D3
significantly attenuated the diabetes-induced impairment so that animals again spent significantly more time exploring
the novel object. The CAT activity was significantly decreased in diabetic animals while the ACE activity was significantly
increased compared to control non-diabetic animals. Diabetes-induced alterations in enzyme activity in the prefrontal cortex
were mitigated by vitamin D3 supplementation.
Conclusion: The present findings demonstrate the potential effect of vitamin D3 supplementation on cognitive function in
diabetic animals. It is possible that this effect was mediated through enhancing the prefrontal cortex cholinergic transmission.
