Related Experiment Video

Updated: Aug 17, 2026

Semi-Quantitative Determination of Dopaminergic Neuron Density in the Substantia Nigra of Rodent Models using Automated Image Analysis
06:09

Semi-Quantitative Determination of Dopaminergic Neuron Density in the Substantia Nigra of Rodent Models using Automated Image Analysis

Published on: February 2, 2021

Microglial inflammation in the parkinsonian substantia nigra: relationship to alpha-synuclein deposition

Emilie Croisier1, Linda B Moran, David T Dexter

  • 1Department of Neuropathology, Division of Neuroscience and Mental Health, Imperial College London, and Hammersmith Hospitals Trust, London, UK. e.croisier@imperial.ac.uk

Journal of Neuroinflammation
|June 7, 2005
PubMed
Abstract

Insights

Microglial activation markers like MHC class II do not reliably indicate Parkinson's disease severity. While microglia respond to alpha-synuclein, their direct role in Parkinson's pathogenesis appears unlikely.

Area of Science:

  • Neuroscience
  • Immunology
  • Pathology

Background:

  • The precise roles of microglial activation and alpha-synuclein in Parkinson's disease (PD) pathogenesis are not fully understood.
  • This study investigated whether microglial activation phenotypes correlate with PD's histopathological and clinical features.

Purpose of the Study:

  • To test the hypothesis that microglia play a primary role in Parkinson's disease pathogenesis.
  • To examine the relationship between microglial activation markers, alpha-synuclein deposition, and clinical/neuropathological features of PD.

Main Methods:

  • Examined microglial MHC class II expression (activation marker) and CD68 (macrophage marker) in post-mortem substantia nigra from PD patients.
  • Assessed alpha-synuclein immunoreactivity and correlated these with PD neuropathological criteria, disease subtype, and clinical course using semi-quantitative ratings.

Main Results:

  • Microglial MHC class II expression did not correlate with clinical PD parameters.
  • A correlation was found between disease duration and CD68 expression in phagocytic microglia.
  • Significant correlation observed between MHC class II expression levels and alpha-synuclein deposition in the substantia nigra.

Conclusions:

  • MHC class II expression in substantia nigra microglia is not a reliable indicator of clinical PD severity or progression.
  • Microglia appear to react to alpha-synuclein, but a primary causative role in PD-associated neuronal loss seems improbable.
  • Caution is advised when assessing microglial activation in aged brains using only MHC class II immunohistochemistry.

More Related Videos

Isolation of Cortical Microglia with Preserved Immunophenotype and Functionality From Murine Neonates09:12

Isolation of Cortical Microglia with Preserved Immunophenotype and Functionality From Murine Neonates

Published on: January 30, 2014

Analyzing the Parkinson's Disease Mouse Model Induced by Adeno-associated Viral Vectors Encoding Human α-Synuclein14:45

Analyzing the Parkinson's Disease Mouse Model Induced by Adeno-associated Viral Vectors Encoding Human α-Synuclein

Published on: July 29, 2022

Related Concept Videos

Parkinson Disease ll: Pathophysiology01:24

Parkinson Disease ll: Pathophysiology

Parkinson disease (PD) is a progressive neurodegenerative disorder primarily affecting movement, with additional non-motor features. Its pathophysiology involves complex interactions among genetic susceptibility, environmental exposures, and cellular dysfunction, including dopaminergic neuron loss, protein aggregation, and mitochondrial impairment.Selective NeurodegenerationA key feature is the degeneration of dopaminergic neurons in the substantia nigra pars compacta, leading to reduced...
Neural Regulation01:37

Neural Regulation

Digestion begins with a cephalic phase that prepares the digestive system to receive food. When our brain processes visual or olfactory information about food, it triggers impulses in the cranial nerves innervating the salivary glands and stomach to prepare for food.
Parkinson Disease l: Introduction01:24

Parkinson Disease l: Introduction

Parkinson’s disease is a chronic, progressive neurodegenerative disorder that primarily affects movement. It is characterized by motor symptoms such as resting tremors, muscle rigidity, bradykinesia (slowness of movement), and postural instability. Patients may notice hand tremors at rest, stiffness during movement, or a shuffling gait. In addition to motor features, non-motor symptoms include sleep disturbances, mood and behavioral changes, constipation, and cognitive impairment, all of which...
Parkinson's Disease: Overview01:15

Parkinson's Disease: Overview

Neurodegenerative disorders are progressive diseases that cause irreversible damage and loss to neurons in specific brain areas. Examples of these disorders include Parkinson's disease, Alzheimer's disease, Multiple Sclerosis (MS), and Amyotrophic Lateral Sclerosis (ALS). These disorders share characteristics such as proteinopathies, selective neuronal vulnerability, and a complex interplay between genetic and environmental factors. The primary therapeutic goal for these conditions is to...