Neuroinflammation in Parkinson's patients and MPTP-treated mice is not restricted to the nigrostriatal system: microgliosis and differential expression of interleukin-1 receptors in the olfactory bulb

Exp Gerontol. 2007 Aug;42(8):762-71. doi: 10.1016/j.exger.2007.04.010. Epub 2007 Apr 29.


Neuroinflammation may play a role in the pathogenesis of Parkinson's disease (PD). The present study questioned whether this neuroinflammatory response differs between the olfactory bulb, as an early affected region and the nigrostriatal system. Indeed, increased microgliosis was shown in post-mortem olfactory bulb of PD patients. Also in olfactory bulb of MPTP-treated mice, microgliosis and increased expression of IL-1alpha, IL-1beta and IL-1ra mRNA was observed early after treatment. These observations implicate that neuroinflammation is not restricted to the nigrostriatal system. MPTP-induced microgliosis in striatum and olfactory bulb was reduced in IL-1alpha/beta knockout mice, indicating that IL-1 affects microglia activation. Importantly, MPTP induced differential regulation of IL-1 receptors. mRNA levels of IL-1RI and, to a lesser extent, IL-1RII were increased in striatum. Interestingly, in the olfactory bulb only IL-1RII mRNA was enhanced. We suggest that differential regulation of IL-1 signaling can serve as an important mechanism to modulate neuroinflammatory activity after MPTP treatment and possibly during PD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Corpus Striatum / drug effects
  • Corpus Striatum / immunology
  • Corpus Striatum / pathology
  • DNA Primers / genetics
  • Gene Expression
  • Humans
  • MPTP Poisoning / genetics
  • MPTP Poisoning / immunology*
  • MPTP Poisoning / pathology*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Microglia / drug effects
  • Microglia / pathology
  • Olfactory Bulb / drug effects
  • Olfactory Bulb / immunology*
  • Olfactory Bulb / pathology*
  • Parkinson Disease / genetics
  • Parkinson Disease / immunology*
  • Parkinson Disease / pathology*
  • Parkinsonian Disorders / genetics
  • Parkinsonian Disorders / immunology*
  • Parkinsonian Disorders / pathology*
  • Receptors, Interleukin-1 / classification
  • Receptors, Interleukin-1 / genetics*
  • Substantia Nigra / drug effects
  • Substantia Nigra / immunology
  • Substantia Nigra / pathology


  • DNA Primers
  • Receptors, Interleukin-1