Table 1.
Microglia respond to changes in neural activity by altering their motility and interactions with synapses.
| Activity perturbation | Effect on microglia | Mechanism/Mediator | Brain region | Anesthetic used | Citation |
|---|---|---|---|---|---|
| Decreased neural activity (general anesthesia, whisker trimming) | Increased motility, process complexity | Norepinephrine | SS (somatosensory) cortex | None | Liu et al. (24) |
| Decreased neural activity (TTX) |
Increased synaptic engulfment | Complement pathway (C1/Cr3) | dLGN | Fixed tissue | Schafer et al. (17) |
| Decreased neural activity (isoflurane, Gi DREADD) | Increased calcium signaling and process extension | Unknown | SS cortex | None | Umpierre et al. (22) |
| Decreased neural activity (TTX, decreased body temp.) |
Decreased synaptic contacts | Unknown | Visual cortex | Ketamine and Xylazine | Wake et al. (20) |
| Decreased neural activity (light deprivation) |
Decreased motility | Unknown | Visual cortex | Fentanyl, Midazolam, and Medetomidine | Tremblay et al. (31) |
| Decreased neural activity (whisker lesioning) | Increased engulfment | Adam10/Fractalkine | SS cortex | Fixed Tissue | Gunner et al (33) |
| Increased neural activity (glutamate, kainate) | Increased process extension | P2Y12 | Hippocampus (Ex vivo) and SS cortex (in vivo) | Unknown | Eyo et al. (27) |
| Increased neural activity (pilocarpine, kainate) | Increased microglial process convergence | Cx3cr1 | Cortex | Isoflurane | Eyo et al. (28) |
| Increased neural activity (kainate, Gq DREADD) |
Increased calcium signaling and process extension | Unknown | SS cortex | None | Umpierre et al. (22) |
| Increased neural activity (bicuculline) | Increased motility | Unknown | SS cortex | Ketamine and Xylazine/Isoflurane | Nimmerjahn et al. (18) |
| Increased neural activity (Gq DREADD) |
Microglial negative feedback to neural activity | ADP release from microglia | Striatum | None | Badimon et al. (25) |
| Increased neural activity (Gq DREADD) or ischemia |
Increased somatic contact | P2Y12 | Cortex | Fentanyl | Cserép et al. (34) |
| Increased neural activity (kainate) | Change in gene expression | Unknown | Hippocampus | N/A | Bosco et al. (29) |
| Increased neural activity (light stimulation) | Increased contact frequency and process motility | Unknown | Cortex, V1 | Fentanyl, Midazolam, and Medetomidine | Tremblay et al. (31) |
| Neural NMDAR activation (NMDA) | Increased motility | NMDA-based release of ATP | Cortex | Fentanyl, Midazolam, and Medetomidine | Dissing-Olesen et al. (26) |
| Tetrapentylammonium (TPA), Increased [K+ o] | Decreased neural surveillance | THIK-1 | Cortex | Urethane | Madry et al. (18) |