Table 1.
Glial response to DBS and electrode implantation in in vivo models.
| References | Species | Condition | Target site | Type of stimulation | Period of experimentation/observation | Nature of the glial response |
|---|---|---|---|---|---|---|
| Han et al., 2012 | Cat | Normal | Inferior colliculus | Chronic | 3–18 months | Observable astrogliosis near the probe at 2 months, but reduced at 5 months |
| Morimoto et al., 2011 | Male Wistar rat | Stroke | Striatum | Chronic | 1 week | Diminished microglial activation with stimulation |
| Hirshler et al., 2010 | Male Sprague-Dawley rat | Normal | Subthalamic nucleus | Electrode implantation only | 1–8 weeks | Astrocytic and microglial activation; more significant in cortex, striatum, and thalamus |
| Baba et al., 2009 | Wistar rat | Stroke | Cortex (ischemic boundary) | Chronic | 1 week | Diminished microglial and astrocytic proliferation |
| Harnack et al., 2008 | Male Wistar rat | Normal | Subthalamic nucleus | Chronic | 3 weeks | Increased number of GFAP+ astrocytes at all anatomical sites as well as thickening of processes |
| Leung et al., 2008 | Rat | Normal | Cortex | Electrode implantation only | 12 weeks | Observable activated microglia attached to the electrodes' external coatings |
| Biran et al., 2007 | Male Fischer-344 rat | Normal | Cortex | Electrode implantation only | 2–4 weeks | Microglia and astrocyte activation around the electrode |
| Lenarz et al., 2007 | Cat | Normal | Inferior colliculus | Semi-chronic (4 h/day) | Implantation: 3 months Stimulation: 60 days beginning 4 weeks post-implantation | Increased GFAP+ cell density around the electrode (greater with the stimulated than the non-stimulated electrode) |
| Stice et al., 2007 | Female Sprague-Dawley rat | Normal | Cortex | Electrode implantation only | 2 and 4 weeks | Astrocytic scar around the electrodes |
| Griffith and Humphrey, 2006 | Rhesus macaque | Normal | Cortex | Electrode implantation only | 3 months and 3 years | Persistent reactive astrogliosis around the electrodes (3 months to 3 years). Transient microglial reaction (present at 3 months but not at 3 years) |
| Biran et al., 2005 | Male Fischer-344 rat | Normal | Cortex | Electrode implantation only | 4 weeks | Persistent activated microglia around the electrode |
| Kim et al., 2004 | Male Fischer-344 rat | Normal | Striatum | Electrode implantation only | 4 weeks | Significant increase in activated microglia in all brain regions |