Influence of probe flexibility and gelatin embedding on neuronal density and glial responses to brain implants.

Per Köhler, Anette Wolff, Fredrik Ejserholm, Lars Wallman, Jens Schouenborg, Cecilia Eriksson Linsmeier

Research output: Contribution to journalArticlepeer-review

221 Downloads (Pure)


To develop long-term high quality communication between brain and computer, a key issue is how to reduce the adverse foreign body responses. Here, the impact of probe flexibility and gelatine embedding on long-term (6w) tissue responses, was analyzed. Probes of same polymer material, size and shape, flexible mainly in one direction, were implanted in rat cerebral cortex (nimplants = 3 x 8) in two orientations with respect to the major movement direction of the brain relative to the skull: parallel to (flex mode) or transverse to (rigid mode). Flex mode implants were either embedded in gelatin or non-embedded. Neurons, activated microglia and astrocytes were visualized using immunohistochemistry. The astrocytic reactivity, but not microglial response, was significantly lower to probes implanted in flex mode as compared to rigid mode. The microglial response, but not astrocytic reactivity, was significantly smaller to gelatin embedded probes (flex mode) than non-embedded. Interestingly, the neuronal density was preserved in the inner zone surrounding gelatin embedded probes. This contrasts to the common reports of reduced neuronal density close to implanted probes. In conclusion, sheer stress appears to be an important factor for astrocytic reactivity to implanted probes. Moreover, gelatin embedding can improve the neuronal density and reduce the microglial response close to the probe.
Original languageEnglish
Article numbere0119340
JournalPLoS ONE
Issue number3
Publication statusPublished - 2015

Subject classification (UKÄ)

  • Neurosciences


Dive into the research topics of 'Influence of probe flexibility and gelatin embedding on neuronal density and glial responses to brain implants.'. Together they form a unique fingerprint.

Cite this