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Glial cells, but not neurons, exhibit a controllable response to a localized inflammatory microenvironment in vitro.

Sommakia S, Rickus JL, Otto KJ - Front Neuroeng (2014)

Bottom Line: Astrocytes exhibit a more complex, distance-dependent response, whereas neurons do not appear to be affected by the type or magnitude of glial response within this in vitro model.The discrepancy between our in vitro responses and typically observed in vivo responses suggest the importance of using a systems approach to understand the responses of the various brain cell types in a chronic in vivo setting, as well as the necessity of studying the roles of cell types not native to the brain.Our results further indicate that the loss of neuronal density observed in vivo is not a necessary consequence of elevated glial activation.

View Article: PubMed Central - PubMed

Affiliation: Weldon School of Biomedical Engineering, Purdue University West Lafayette, IN, USA ; Physiological Sensing Facility at the Bindley Bioscience Center and Birck Nanotechnology Center, Purdue University West Lafayette, IN, USA.

ABSTRACT
The ability to design long-lasting intracortical implants hinges on understanding the factors leading to the loss of neuronal density and the formation of the glial scar. In this study, we modify a common in vitro mixed cortical culture model using lipopolysaccharide (LPS) to examine the responses of microglia, astrocytes, and neurons to microwire segments. We also use dip-coated polyethylene glycol (PEG), which we have previously shown can modulate impedance changes to neural microelectrodes, to control the cellular responses. We find that microglia, as expected, exhibit an elevated response to LPS-coated microwire for distances of up to 150 μm, and that this elevated response can be mitigated by co-depositing PEG with LPS. Astrocytes exhibit a more complex, distance-dependent response, whereas neurons do not appear to be affected by the type or magnitude of glial response within this in vitro model. The discrepancy between our in vitro responses and typically observed in vivo responses suggest the importance of using a systems approach to understand the responses of the various brain cell types in a chronic in vivo setting, as well as the necessity of studying the roles of cell types not native to the brain. Our results further indicate that the loss of neuronal density observed in vivo is not a necessary consequence of elevated glial activation.

No MeSH data available.


Related in: MedlinePlus

No differences are observed in neuronal responses in interface areas of various widths.
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Figure 6: No differences are observed in neuronal responses in interface areas of various widths.

Mentions: Figures 6, 7 show the neuron RI in interface and distant regions respectively. No significant differences in the neuron response were found between any of the treatment conditions in either interface or distant region. In contrast to microglia and astrocytes, where the RI was higher in distant areas in comparison to the widest interface area examined, the neuron RI in distant areas was roughly equal to that in the widest interface area examined.


Glial cells, but not neurons, exhibit a controllable response to a localized inflammatory microenvironment in vitro.

Sommakia S, Rickus JL, Otto KJ - Front Neuroeng (2014)

No differences are observed in neuronal responses in interface areas of various widths.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4231942&req=5

Figure 6: No differences are observed in neuronal responses in interface areas of various widths.
Mentions: Figures 6, 7 show the neuron RI in interface and distant regions respectively. No significant differences in the neuron response were found between any of the treatment conditions in either interface or distant region. In contrast to microglia and astrocytes, where the RI was higher in distant areas in comparison to the widest interface area examined, the neuron RI in distant areas was roughly equal to that in the widest interface area examined.

Bottom Line: Astrocytes exhibit a more complex, distance-dependent response, whereas neurons do not appear to be affected by the type or magnitude of glial response within this in vitro model.The discrepancy between our in vitro responses and typically observed in vivo responses suggest the importance of using a systems approach to understand the responses of the various brain cell types in a chronic in vivo setting, as well as the necessity of studying the roles of cell types not native to the brain.Our results further indicate that the loss of neuronal density observed in vivo is not a necessary consequence of elevated glial activation.

View Article: PubMed Central - PubMed

Affiliation: Weldon School of Biomedical Engineering, Purdue University West Lafayette, IN, USA ; Physiological Sensing Facility at the Bindley Bioscience Center and Birck Nanotechnology Center, Purdue University West Lafayette, IN, USA.

ABSTRACT
The ability to design long-lasting intracortical implants hinges on understanding the factors leading to the loss of neuronal density and the formation of the glial scar. In this study, we modify a common in vitro mixed cortical culture model using lipopolysaccharide (LPS) to examine the responses of microglia, astrocytes, and neurons to microwire segments. We also use dip-coated polyethylene glycol (PEG), which we have previously shown can modulate impedance changes to neural microelectrodes, to control the cellular responses. We find that microglia, as expected, exhibit an elevated response to LPS-coated microwire for distances of up to 150 μm, and that this elevated response can be mitigated by co-depositing PEG with LPS. Astrocytes exhibit a more complex, distance-dependent response, whereas neurons do not appear to be affected by the type or magnitude of glial response within this in vitro model. The discrepancy between our in vitro responses and typically observed in vivo responses suggest the importance of using a systems approach to understand the responses of the various brain cell types in a chronic in vivo setting, as well as the necessity of studying the roles of cell types not native to the brain. Our results further indicate that the loss of neuronal density observed in vivo is not a necessary consequence of elevated glial activation.

No MeSH data available.


Related in: MedlinePlus