General Information

Mouse: C57BL/6

Mice in which exon 3-5 gene was deleted leading to the absence of DJ-1 protein in homozygous DJ-1-/- mice. Reproductive functions are not affected by the loss of DJ-1 expression.

Endogenous DJ-1: No

Corresponding human genotype: Autosomal recessive genetic deletion in the DJ-1 gene causing a loss-of-function of the protein and leading to early-onset Parkinson’s disease (PARK7).

Mutated gene: DJ-1

References: Kim, 2005;Sanchez, 2014; Rousseaux 2012; Zhou 2017

Loss of dopaminergic neurons

  • 8-10 weeks: No apparent changes in the number TH-positive neurons and terminals are observed. An increased sensitivity to MPTP treatment is observed in the striatum and the SNc.(Kim; SAnchez)
  • 2 months: unilateral loss of TH-positive neurons is observed in the SN and not in the VTA of in a subset of animals. No reduction of DA terminals is observed in the striatum (suggesting neurites sprouting) at this age
  • 15 months: Unilateral reduction of TH-positive terminals is observed in the striatum (reduced sprouting) and in the LC

Dopamine Homeostasis

  • 8-10 weeks: no changes in striatal levels of dopamine and dopamine metabolites are detected. An increased sensitivity to MPTP is observed with a more pronounced reduction of dopamine levels observed in DJ-1-/- mice compared to wild type
  • 8 weeks: no differences in dopamine evoked overflow is observed using FSCV

Inclusions

  • 3 and 12 months: No inclusions are observed

Motor Behaviours

  • 8 weeks, 2, 6 and 13 months: No statistically significant differences are observed in spontaneous locomotor activity as measured in the open field test (both horizontal and vertical movements). Similarly, no changes in the pole test are detected.
  • 14-16 months: mild motor deficit is observed (grid and pole test)
  • 8-10 weeks: Treatment with MPTP caused a more significant reduction in spontaneous locomotor activity in DJ-1-/- compared to wild type mice. Reduced activity is observed in DJ-1-/- mice compared to wild type following amphetamine challenge (2mg/kg).
  • 10 months: motor deficits is observed (rotarod)

Response to dopaminergic treatment

  • Not reported

Non motor Behaviours

  • 8 weeks and 13 months: no differences in novel environment and somatosensory tests are detected
  • 10 months: normal cognitive function (Morris water maze and exploratory activity)

Electrophysiology

  • not reported

Neuroinflammation

  • 2 months: animals displaying unilateral loss of TH-positive neurons in the SN show clear activation of microglial cells in the affected side. No astroglial activation is observed.

Updated 25/04/2018