Glial alterations in the hippocampus of rats submitted to ibotenic-induced lesion of the nucleus basalis magnocellularis

Behav Brain Res. 2008 Jul 19;190(2):206-11. doi: 10.1016/j.bbr.2008.02.039. Epub 2008 Mar 6.

Abstract

Lesion of the nucleus basalis magnocellularis (nbm) is a suitable approach to study cognitive deficit and behavior alterations involving cholinergic dysfunction, which is associated with the major types of dementia. Cortical astrogliosis also has been described in this model, but it is not clear whether hippocampal astrocytes are activated. In this study, we investigated possible specific astrocyte alterations in the hippocampi of Wistar rats submitted to nbm damage with ibotenic acid, investigating the content and immunohistochemistry of glial fibrillary acidic protein (GFAP), as well as S100B protein content, glutamate uptake and glutamine synthetase activity on the 7th and 28th post-lesion days. Cognitive deficit was confirmed by the step-down inhibitory avoidance task. Interestingly, we found a decrease in GFAP content, S100B content and glutamate uptake activity in the hippocampus on the 28th day after nbm lesion. No alterations were observed in glutamine synthetase activity or in the cerebrospinal fluid S100B content. Although our data suggest caution in the use of nbm lesion with ibotenic acid as a dementia model, it is possible that these alterations could contribute to the cognitive deficit observed in these rats.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Astrocytes / cytology*
  • Astrocytes / metabolism
  • Avoidance Learning / physiology*
  • Basal Nucleus of Meynert / cytology
  • Basal Nucleus of Meynert / drug effects
  • Basal Nucleus of Meynert / physiology*
  • Brain Damage, Chronic / chemically induced
  • Cell Count
  • Cholinergic Fibers / metabolism*
  • Dementia / metabolism
  • Dementia / physiopathology*
  • Disease Models, Animal
  • Exploratory Behavior / physiology
  • Follow-Up Studies
  • Glial Fibrillary Acidic Protein / metabolism
  • Glutamate-Ammonia Ligase / metabolism
  • Glutamic Acid / metabolism
  • Habituation, Psychophysiologic / physiology
  • Hippocampus / cytology*
  • Hippocampus / metabolism
  • Ibotenic Acid
  • Immunohistochemistry
  • Male
  • Nerve Growth Factors / metabolism
  • Rats
  • Rats, Wistar
  • S100 Calcium Binding Protein beta Subunit
  • S100 Proteins / metabolism
  • Statistics, Nonparametric
  • Time Factors

Substances

  • Glial Fibrillary Acidic Protein
  • Nerve Growth Factors
  • S100 Calcium Binding Protein beta Subunit
  • S100 Proteins
  • S100b protein, rat
  • Ibotenic Acid
  • Glutamic Acid
  • Glutamate-Ammonia Ligase