Format

Send to:

Choose Destination
See comment in PubMed Commons below
J Neural Eng. 2012 Dec;9(6):066001. doi: 10.1088/1741-2560/9/6/066001. Epub 2012 Oct 17.

In vivo two-photon microscopy reveals immediate microglial reaction to implantation of microelectrode through extension of processes.

Author information

  • 1Department of Bioengineering, University of Pittsburgh, PA, USA.

Abstract

OBJECTIVE:

Penetrating cortical neural probe technologies allow investigators to record electrical signals in the brain. Implantation of probes results in acute tissue damage, and microglia density increases around implanted devices over weeks. However, the mechanisms underlying this encapsulation are not well understood in the acute temporal domain. The objective here was to evaluate dynamic microglial response to implanted probes using two-photon microscopy.

APPROACH:

Using two-photon in vivo microscopy, cortical microglia ∼200 µm below the surface of the visual cortex were imaged every minute in mice with green fluorescent protein-expressing microglia.

MAIN RESULTS:

Following probe insertion, nearby microglia immediately extended processes toward the probe at (1.6 ± 1.3) µm min(-1) during the first 30-45 min, but showed negligible cell body movement for the first 6 h. Six hours following probe insertion, microglia at distances <130.0 µm (p = 0.5) from the probe surface exhibit morphological characteristics of transitional stage (T-stage) activation, similar to the microglial response observed with laser-induced blood-brain barrier damage. T-stage morphology and microglia directionality indexes were developed to characterize microglial response to implanted probes. Evidence suggesting vascular reorganization after probe insertion and distant vessel damage was also observed hours after probe insertion.

SIGNIFICANCE:

A precise temporal understanding of the cellular response to microelectrode implantation will facilitate the search for molecular cues initiating and attenuating the reactive tissue response.

PMID:
23075490
[PubMed - indexed for MEDLINE]
PMCID:
PMC3511663
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for IOP Publishing Ltd. Icon for PubMed Central
    Loading ...
    Write to the Help Desk