Sustained glial reactivity induced by glutaric acid may be the trigger to learning delay in early and late phases of development: Involvement of p75NTR receptor and protection by N-acetylcysteine

Brain Res. 2020 Dec 15:1749:147145. doi: 10.1016/j.brainres.2020.147145. Epub 2020 Oct 6.

Abstract

Degeneration of striatal neurons and cortical atrophy are pathological characteristics of glutaric acidemia type I (GA-I), a disease characterized by accumulation of glutaric acid (GA). The mechanisms that lead to neuronal loss and cognitive impairment are still unclear. The purpose of this study was to verify if acute exposure to GA during the neonatal period is sufficient to trigger apoptotic processes and lead to learning delay in early and late period. Besides, whether N-acetylcysteine (NAC) would protect against impairment induced by GA. Pups mice received a dose of GA (2.5 μmol/ g) or saline, 12 hs after birth, and were treated with NAC (250 mg/kg) or saline, up to 21th day of life. Although GA exhibited deficits in the procedural and working memories in 21 and 40-day-old mice, NAC protected against cognitive impairment. In striatum and cortex, NAC prevented glial cells activation (GFAP and Iba-1), decreased NGF, Bcl-2 and NeuN, the increase of lipid peroxidation and PARP induced by GA in both ages. NAC protected against increased p75NTR induced by GA, but not in cortex of 21-day-old mice. Thus, we showed that the integrity of striatal and cortical pathways has an important role for learning and suggested that sustained glial reactivity in neonatal period can be an initial trigger for delay of cognitive development. Furthermore, NAC protected against cognitive impairment induced by GA. This work shows that early identification of the alterations induced by GA is important to avoid future clinical complications and suggest that NAC could be an adjuvant treatment for this acidemia.

Keywords: Cortex; Glutaric acid; Learning; Memory; Neuronal death; Striatum.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcysteine / pharmacology*
  • Animals
  • Apoptosis / drug effects
  • Cerebral Cortex / drug effects*
  • Cerebral Cortex / metabolism
  • Cognition / drug effects
  • Corpus Striatum / drug effects*
  • Corpus Striatum / metabolism
  • Glutarates / pharmacology*
  • Lipid Peroxidation / drug effects
  • Male
  • Maze Learning / drug effects*
  • Mice
  • Neurons / drug effects
  • Neurons / metabolism
  • Neuroprotective Agents / pharmacology
  • Oxidative Stress / drug effects
  • Receptors, Nerve Growth Factor / metabolism*

Substances

  • Glutarates
  • Neuroprotective Agents
  • Receptors, Nerve Growth Factor
  • Ngfr protein, mouse
  • glutaric acid
  • Acetylcysteine