Development of neurological reflexes and motor coordination in rats neonatally treated with monosodium glutamate

Neurotox Res. 2005 Nov;8(3-4):235-44. doi: 10.1007/BF03033977.

Abstract

Monosodium glutamate (MSG) treatment of neonatal rats causes neuronal degeneration in various brain areas and leads to several neurochemical, endocrinological and behavioral alterations. However, relatively little is known about the development of neurological reflexes and motor coordination of these animals. Therefore, the aim of the present study was to examine the neurobehavioral development of newborn rats treated with MSG. Rats received MSG at postnatal days 1, 3, 5, 7, and 9. Appearance of neural reflexes and reflex performance as well as motor coordination were examined for 5 weeks after birth. The efficacy of MSG treatment was confirmed by histological examination of the arcuate nucleus. We found that MSG treatment delayed the appearance of forelimb placing, forelimb grasp and righting reflexes, besides the retarded somatic development. The treated pups performed surface righting in significantly longer times. Also, worse performance was observed in the foot-fault and rota-rod tests. However, MSG-treated rats reached control levels by the end of the fifth postnatal week. These results show that MSG treatment does not cause permanent alterations in the neurobehavioral development, only delays the appearance of some reflexes and leads to temporary changes in reflex performance and motor coordination signs.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Animals
  • Animals, Newborn
  • Arcuate Nucleus of Hypothalamus / drug effects
  • Arcuate Nucleus of Hypothalamus / growth & development
  • Arcuate Nucleus of Hypothalamus / pathology
  • Behavior, Animal
  • Body Weight / drug effects
  • Motor Activity / drug effects
  • Motor Activity / physiology
  • Nerve Degeneration / chemically induced*
  • Nerve Degeneration / physiopathology*
  • Psychomotor Performance / drug effects*
  • Rats
  • Rats, Wistar
  • Reflex / drug effects*
  • Rotarod Performance Test / methods
  • Sodium Glutamate / toxicity*
  • Time Factors
  • Walking

Substances

  • Sodium Glutamate