Name: Video: In Vivo Quantification of Microglial Engulfment of Glutamatergic Synapses with Intracellular vGLUT1 Staining
Uploaded: 2024-05-31T13:40:00
Duration: 2 min 55 s
Description: 175 Views. In Vivo Quantification of Microglial Engulfment of Glutamatergic Synapses with Intracellular vGLUT1 Staining

in vivo quantification of microglial engulfment of glutamatergic synapses with intracellular vglut1 staining

Flow Cytometry-Based Assays for Microglial Engulfment of Synaptic Materials

Microglia are the resident immune cells of the central nervous system (CNS)1. They constantly scan their microenvironment and provide surveillance1,2. Moreover, they frequently interact with synapses and mediate a fine-tuning of the synaptic activity3. Thus, they have emerged as a key player in the process of synaptic refinement.
The role of microglia in synaptic refinement through the engulfment of synapses has been shown by various research groups3,4,5,6,7. Disruptions in this process can contribute to the pathology of neurodevelopmental and neurodegenerative disorders such as schizophrenia and Alzheimer&#39;s disease8. Aberrant synaptic refinement by microglia has already been detected in various murine models of neurological disorders5,9,10. Therefore, identification of distinct mechanisms underlying microglial engulfment of synapses is paramount to understanding the pathophysiology of neurodevelopmental and neurodegenerative disorders8.
Targeting microglial engulfment of synapses holds great potential for both intervening in disease progression and gaining insights into the underlying mechanisms of neurodevelopmental and neurodegenerative disorders. To facilitate such investigations, there is a need for fast and high-throughput approaches. Current methodological approaches encompass in vivo, ex vivo, and in vitro assays that enable the detection of synaptic material within microglia. Generally, the detection of microglial engulfment of synapses relies heavily on immunohistochemistry (IHC) and microscopy-based approaches5,6,11, which are labor-intensive and show limitations in analyzing a large number of microglia.
Given these technical limitations, the exploration of alternative methodologies is imperative. To overcome this, we have optimized a flow cytometry-based approach, which enables an efficient, unbiased, and high-throughput analysis of microglial engulfment of synapses. We chose the hippocampus as the main region of interest due to its high degree of synaptic remodeling and plasticity12, but the protocol can be adapted to various brain regions. While flow cytometry has already been used in previous studies to detect microglial engulfment of synapses13,14,15, we herein provide a step-by-step methodology employing a currently commercially available, fluorophore-conjugated vGLUT1 antibody. We, moreover, provide a complementary&#160;in vitro approach for high-throughput screening of microglial engulfment of synaptic material by using crude synaptosomes.

Author Spotlight: Advancing Understanding Through Technological Innovations in Psychoneuroimmunology

Quantification of Microglial Engulfment of Synaptic Material Using Flow Cytometry

In Vivo Quantification of Microglial Engulfment of Glutamatergic Synapses with Intracellular vGLUT1 Staining

in-vivo-quantification-microglial-engulfment-glutamatergic-synapses

Research

JoVE Journal

Neuroscience

175 Views. In Vivo Quantification of Microglial Engulfment of Glutamatergic Synapses with Intracellular vGLUT1 Staining

Video: In Vivo Quantification of Microglial Engulfment of Glutamatergic Synapses with Intracellular vGLUT1 Staining

Microglia play a pivotal role in synaptic refinement in the brain. Analysis of microglial engulfment of synapses is essential for comprehending this process; however, currently available methods for identifying microglial engulfment of synapses, such as immunohistochemistry (IHC) and imaging, are laborious and time-intensive. To address this challenge, herein we present in vitro and in vivo* assays that allow fast and high-throughput quantification of microglial engulfment of synapses using flow cytometry.
In the in vivo* approach, we performed intracellular vGLUT1 staining following fresh cell isolation from adult mouse brains to quantify engulfment of vGLUT1+ synapses by microglia. In the in vitro synaptosome engulfment assay, we used freshly isolated cells from the adult mouse brain to quantify the engulfment of pHrodo&#160;Red-labeled synaptosomes by microglia. These protocols together provide a time-efficient approach to quantifying microglial engulfment of synapses and represent promising alternatives to labor-intensive image analysis-based methods. By streamlining the analysis, these assays can contribute to a better understanding of the role of microglia in synaptic refinement in different disease models.

Here we present two protocols to quantify microglial engulfment of vGLUT1-positive synapses and pHRodo&#160;Red-labeled crude synaptosomes using flow cytometry.

Microglia play a pivotal role in synaptic refinement in the brain. Analysis of microglial engulfment of synapses is essential for comprehending this ...