Skip to main content

Table 2 Effects of enriched environment on microglia

From: Lifestyle-dependent microglial plasticity: training the brain guardians

Species

Brain region

Experimental paradigm

Microglial changes

References

Mice

Hippocampus, amygdala and hypothalamus

EE for 32 and 48 weeks

EE reduced expression of pro-inflammatory cytokines, increased Iba1 expression, and induced microglial hypertrophy and increased ramification

[79]

Mice

Hippocampus

EE for 7–8 weeks

EE prevents microgliosis induced by human β-amyloid oligomers, as evidenced by morphology, mRNA changes, and brain interstitial fluid cytokine levels

[81]

Mice

Hippocampus and hypothalamus

EE for 6 weeks

EE housing blocks pro-inflammatory cytokine gene induction and promotes arginase 1 mRNA expression in brain-sorted microglia, indicating that EE favours an anti-inflammatory activation state

[143]

Mice

Hippocampus and neocortex

EE for 6 weeks

EE in APP/PS1 mice amyloidosis model led to improved short-term memory, reduced microgliosis and increased microglial phagocytic activity

[83]

Mice

 

EE for 4–6 weeks

EE acting through enhanced β-adrenergic signalling reduces microgliosis in response to direct exposure to β-amyloid

[82]

Mice

Hippocampus

EE, PE, and EE + PE for 7 weeks

EE led to an increased microglial number at 5 and 10 months while PE and EE + PE increased microglial numbers only at 10 months

[78]

Mice

Amygdala

EE or PE for 40 days

EE Increased microglial proliferation

[144]

Rat

Hippocampus

EE for 12 weeks

EE ameliorates cognitive comorbidities associated with type I diabetes mellitus, possibly by reducing hyperactivity in the hypothalamic–pituitary–adrenal axis and microglial reactivity in diabetic animals

[91]

Mice

Hippocampus

EE for 87 weeks

Long-term EE reduces microglia morphological diversity of the molecular layer of dentate gyrus

[88]

Mice

Lateral septum

EE for 32 weeks

Following dengue infection, EE led to a reduction of microglial morphological diversity

[145]

Mice

Hippocampus, septum, olfactory bulb and brainstem

EE for 16 weeks

EE alleviated microgliosis, promoted faster viral clearance, decreased viral dissemination, reduced disease progression, and decreased CNS damage in a model of limbic encephalitis

[90]

Mice

Hippocampus

EE for 12 weeks

EE attenuated microgliosis, damage to the extracellular matrix and promoted virus clearance in a model of viral encephalitis

[89]

Mice

Striatum

EE for 7 weeks

Glioma-bearing mice housed in EE have increased branching and patrolling activity microglia, besides increased phagocytic activity

[92]

Pig

Frontal cortex

EE for 3 weeks

EE piglets displayed a signature consistent with a relative decrease in microglial activity compared to those in the standard condition

[146]

  1. EE enriched environment, PE physical exercise, APP/PS1 amyloid precursor protein/presenilin1 mouse Alzheimer's disease model mice