Chronic peripheral inflammation, hippocampal neurogenesis, and behavior

Area of Science:

• Neuroscience
• Immunology
• Pathology

Background:

• Adult hippocampal neurogenesis is crucial for memory, learning, and mood regulation.
• Chronic peripheral inflammation, from illness, metabolic disorders, or aging, is linked to cognitive and mood disturbances.
• Pro-inflammatory cytokines mediate peripheral inflammation's impact on the brain, activating microglia.

Purpose of the Study:

• To review evidence linking chronic peripheral inflammation to reduced adult hippocampal neurogenesis.
• To explore the mechanisms by which inflammation affects neurogenesis.
• To correlate these findings with behavioral disturbances in animal models and human patients.

Main Methods:

• Review of existing literature on animal models of chronic peripheral inflammation.
• Analysis of studies investigating neurogenesis in these models.
• Consideration of human clinical data on cognitive and mood disorders in inflammatory conditions.

Main Results:

• Chronic peripheral inflammation activates brain microglia, suppressing neurogenesis.
• Microglial activation inhibits neuronal stem cell proliferation, increases progenitor cell apoptosis, and reduces new neuron survival.
• Animal models show disrupted neurogenesis correlates with cognitive deficits and depression-like behaviors.

Conclusions:

• Chronic peripheral inflammation impairs adult hippocampal neurogenesis, contributing to cognitive and mood disorders.
• Microglia play a key role in mediating the detrimental effects of peripheral inflammation on the brain.
• Further research, including human studies, is needed to fully understand this relationship.