Magnesium deficiency impairs fear conditioning in mice.
Magnesium (Mg2+) is one of the most abundant cations found in the body. In the central nervous system, Mg2+ plays an important role in the function of N-methyl-D-aspartate (NMDA)-type glutamate receptors, which are centrally involved in memory processing. Despite the relatively large concentration of Mg2+ in the CNS, little is known about the behavioral consequences of Mg2+ deficiency. The purpose of this study was to address this issue by assessing fear conditioning and related behaviors in mice maintained on normal or Mg(2+)-deficient diets. Young adult male C57Bl/6J mice were placed on a control or Mg(2+)-deficient diet, and testing was conducted between 10 and 21 days later. Magnesium-deficient mice exhibited impairments in contextual and cued fear conditioning. These impairments could not be attributed to changes in locomotor activity, exploration, or pain sensitivity. Furthermore, Mg(2+)-deficient mice were more sensitive to the convulsant effects of a peripheral injection of NMDA (100 mg/kg, IP). The results suggest that magnesium deficiency can lead to specific impairments in emotional memory. Such impairments may be related to hypersensitivity of NMDA-type glutamate receptors in Mg(2+)-deficient mice.
Bardgett
Mark E
ME
Department of Psychology, Northern Kentucky University, One Nunn Drive, Highland Heights, KY 41099, USA. bardgettm@nku.edu
Schultheis
Patrick J
PJ
McGill
Diana L
DL
Richmond
Raymond E
RE
Wagge
Jordan R
JR
D000818:Animals; D003214:Conditioning, Classical / Q000502:physiology*; D005106:Exploratory Behavior / Q000502:physiology; D005239:Fear / Q000502:physiology*; D008274:Magnesium / Q000378:metabolism*; D008275:Magnesium Deficiency / Q000503:physiopathology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009043:Motor Activity / Q000502:physiology; D016202:N-Methylaspartate; D017288:Pain Threshold / Q000502:physiology; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology*; D012640:Seizures / Q000139:chemically induced / Q000503:physiopathology
D016194:Receptors, N-Methyl-D-Aspartate; D016202:N-Methylaspartate; D008274:Magnesium