Niacin dietary supplement does not influence spatial learning behaviours in adult rats on chronic intermittent ethanol exposure

Abstract

Niacin has been shown to be effective in the management of pellagra, a disease of niacin deficiency characterized by dermatitis, diarrhea, dementia and possibly death. Pellagra is commonly found among chronic alcoholics. Chronic intermittent ethanol (CIE) exposure is shown to affect spatial learning in adolescent rats while niacin dietary deficiency is found to inversely correlate with spatial learning in the same group. No study has examined the effects of niacin dietary supplement on spatial learning in CIE and healthy control older rats. This study was a preliminary assessment of niacin supplement in this population. Twenty adult Wistar Rats between 8 and 9 months of age, with mean weight of 0.35kg, were used for the study. The subjects were randomly assigned into four groups: 1) rats exposed to 3g/kg ethanol, 2) rats exposed to 3g/kg ethanol and 30 mg/kg body weight niacin supplement, 3) rats exposed to 30 mg/kg body weight niacin supplement alone, and 4) control rats exposed distilled water. Animals were tested at two different periods (i.e., post treatment exposure and after one month of abstinence) on simple (9 alleys) and complex (14 alleys) Hebb-William maze boxes respectively. Our findings show no significant differences on spatial learning among the four groups in both time points. This data reveals that in the experimental model herein used, niacin supplement had no significant effect on spatial learning memory in adult rats and did not conform with previous data on inverse effects of niacin deficiency in spatial learning among adolescent population.

Key words: Ethanol, Spatial learning, Niacin, Hippocampus, older rats