Female mice are resilient to age-related decline of substantia nigra dopamine neuron firing parameters

Neurobiol Aging. 2020 Nov;95:195-204. doi: 10.1016/j.neurobiolaging.2020.07.025. Epub 2020 Aug 3.

Abstract

Degeneration of substantia nigra pars compacta dopamine neurons is a central feature in the pathology of Parkinson's disease, which is characterized by progressive loss of motor and cognitive functions. The largest risk factors for Parkinson's disease are age and sex; most cases occur after age 60 and males have nearly twice the incidence as females. Preclinical work has scarcely considered the influence of these 2 factors to disease risk and presentation. Here, we observed a progressive decline in dopamine neuron firing activity in male C57BL/6 mice by 18 months of age, while dopamine neurons from females remained largely unaffected. This was accompanied by increased mRNA expression of PINK1 in both males and females, and PARK2 primarily in males, both of which have been linked to Parkinson's. Since the declining cell properties were accompanied by only slight decreases in locomotion in both sexes, it is likely that these age-related impairments in males represent a vulnerability to further insults that could predispose the neurons to neurodegenerative processes such as in Parkinson's.

Keywords: Aging; Dopamine; Electrophysiology; Firing; Mouse; Substantia nigra.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Aging / pathology*
  • Aging / physiology*
  • Animals
  • Disease Progression
  • Dopaminergic Neurons / pathology*
  • Dopaminergic Neurons / physiology*
  • Electrophysiological Phenomena
  • Female
  • Gene Expression
  • Humans
  • Male
  • Mice, Inbred C57BL
  • Neurodegenerative Diseases / genetics
  • Neurodegenerative Diseases / pathology
  • Parkinson Disease / genetics
  • Parkinson Disease / pathology
  • Protein Kinases / genetics
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Risk
  • Sex Factors
  • Substantia Nigra / cytology*
  • Substantia Nigra / pathology*
  • Ubiquitin-Protein Ligases / genetics

Substances

  • RNA, Messenger
  • Ubiquitin-Protein Ligases
  • parkin protein
  • Protein Kinases
  • PTEN-induced putative kinase