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Culturing Microglia from the Neonatal and Adult Central Nervous System
Published on: August 9, 2013
Transformation of leech microglial cell morphology and properties following co-culture with injured central nervous
1Department of Pharmacology, Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland. nicholls@sissa.it.
Abstract:
When the leech central nervous system (CNS) is injured, microglial cells migrate to the site of the lesion. It is possible that the injured CNS releases diffusible substances that alter the properties of microglial cells; to investigate this, microglial cells were cultured in the presence of injured or uninjured CNS tissue. Grown on Concanavalin A (Con-A), 75 % of microglial cells are rounded in shape and are avoided by growing neurites. However, when chains of leech ganglia with damaged connectives were cultured on Con-A next to microglial cells, many of the microglial cells changed their morphology. The number of rounded cells present decreased to 48 %, 4 % became spindle-shaped and 48 % had an intermediate form. In addition, the presence of crushed ganglionic chains allowed more growth of neurites across microglial cells than occurred under control conditions, although round-shaped microglia were still avoided by growing neurites. Similar changes in microglial cells were produced in cells plated on Con-A in the presence of conditioned medium from crushed ganglionic chains. Hence, a diffusible substance from injured CNS tissue caused the morphology of the microglial cells plated on Con-A to become more like that of microglia plated on laminin, on which only 22 % of the cells are rounded while the remainder are spindle-shaped and are readily crossed by neurites. Changes in morphology were not observed when microglial cells were cultured with frozen and crushed ganglionic chains or with uncrushed chains. These experiments demonstrate that substances released from damaged leech CNS cause microglial cells plated on Con-A to change their morphology and the way in which they interact with growing neurites.
Insights
Injured central nervous system (CNS) tissue releases diffusible substances that alter microglial cell morphology and neurite interactions. This finding is crucial for understanding CNS repair mechanisms in leeches.
Area of Science:
- Neuroscience
- Cell Biology
- Developmental Biology
Background:
- Microglial cells are immune cells of the central nervous system (CNS).
- In leeches, microglial cells migrate to sites of CNS injury.
- The role of diffusible substances from injured CNS in modulating microglial behavior is not fully understood.
Purpose of the Study:
- To investigate whether diffusible substances released from injured leech CNS alter microglial cell morphology and interaction with growing neurites.
- To characterize the nature of these diffusible substances.
Main Methods:
- Culturing leech microglial cells on Concanavalin A (Con-A) coated surfaces.
- Introducing injured or uninjured leech CNS tissue or conditioned medium from injured CNS to the microglial cultures.
- Observing and quantifying microglial cell morphology (rounded, spindle-shaped, intermediate).
- Assessing neurite outgrowth and interaction with microglial cells.
Main Results:
- Microglial cells cultured with injured CNS tissue or conditioned medium showed significant morphological changes compared to controls.
- The percentage of rounded microglial cells decreased, with a notable increase in spindle-shaped and intermediate forms.
- Injured CNS factors promoted neurite outgrowth across microglial cells, although rounded microglia were still avoided.
- These effects were specific to diffusible substances from damaged CNS, not frozen or uncrushed tissue.
Conclusions:
- Diffusible substances released from damaged leech CNS induce significant changes in microglial cell morphology.
- These substances alter the interaction between microglial cells and growing neurites, potentially influencing CNS repair.
- The findings highlight a novel mechanism of CNS injury response mediated by microglial cells in leeches.
