Table 3.

Microglia regulation of learning and memory and experience-dependent plasticity

L&M and EDP	Experimental models	Main findings	Reference
Memory precision	IL-33mCherry/+ and IL1RL1-cKO mice	•Microglia IL-33 signaling promotes EDP via the engulfment of ECM	Nguyen et al., 2020
		•IL-33 promotes context discrimination in aged mice
Forgetfulness of remote memory	c-Fos-CreERT2::	•Microglia modulate forgetting via adult neurogenesis	Wang et al., 2020
	Ai14 mice to label engram cells	•CD55, an inhibitor for complement, prevents microglia-mediated forgetting via phagocytosis
Somatosensory EDP	Whisker deprivation in CD-1 mice	•Microglia are critical to maintain EDP during the critical developmental period	Kalambogias et al., 2020
		•Microglia transit from a resting state to an altered morphological state under chronic sensory deprivation
Visual EDP	Monocular deprivation in P2Y12 KO mice	•The disruption of P2Y12 receptors on microglia alters its response to monocular deprivation and abrogates ocular dominance plasticity	Sipe et al., 2016
Arousal state on visual EDP	Monocular deprivation in B2-AR-flox mice	•Microglia surveillance and injury response are lessened in awake mice compared to anesthetized mice	Stowell et al., 2019
		•Stimulated noradrenergic tone on microglia disrupts ocular dominance plasticity

CD55: Complement decay-accelerating factor; ECM: extracellular matrix; EDP: experience-dependent plasticity; IL-33: interleukin-33; L&M: learning and memory.