Substantial acetylcholine reduction in multiple brain regions of Mecp2-deficient female rats and associated behavioral abnormalities

PLoS One. 2021 Oct 21;16(10):e0258830. doi: 10.1371/journal.pone.0258830. eCollection 2021.

Abstract

Rett syndrome (RTT) is a neurodevelopmental disorder with X-linked dominant inheritance caused mainly by mutations in the methyl-CpG-binding protein 2 (MECP2) gene. The effects of various Mecp2 mutations have been extensively assessed in mouse models, but none adequately mimic the symptoms and pathological changes of RTT. In this study, we assessed the effects of Mecp2 gene deletion on female rats (Mecp2+/-) and found severe impairments in social behavior [at 8 weeks (w), 12 w, and 23 w of age], motor function [at 16 w and 26 w], and spatial cognition [at 29 w] as well as lower plasma insulin-like growth factor (but not brain-derived neurotrophic factor) and markedly reduced acetylcholine (30%-50%) in multiple brain regions compared to female Mecp2+/+ rats [at 29 w]. Alternatively, changes in brain monoamine levels were relatively small, in contrast to reports on mouse Mecp2 mutants. Female Mecp2-deficient rats express phenotypes resembling RTT and so may provide a robust model for future research on RTT pathobiology and treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcholine / metabolism*
  • Animals
  • Animals, Genetically Modified / genetics
  • Animals, Genetically Modified / metabolism
  • Brain / metabolism*
  • Cognition*
  • Disease Models, Animal
  • Female
  • Learning
  • Locomotion*
  • Memory / physiology*
  • Methyl-CpG-Binding Protein 2 / physiology*
  • Rats
  • Social Behavior*

Substances

  • Mecp2 protein, rat
  • Methyl-CpG-Binding Protein 2
  • Acetylcholine

Grants and funding

The funder, Nihon Bioresearch Inc, provided support in the form of salaries for authors: HM, HK, JI, and TN, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. No additional external funding was received for this study.