Mold inhalation causes innate immune activation, neural, cognitive and emotional dysfunction

Area of Science:

• Neuroscience
• Immunology
• Toxicology

Background:

• Moldy buildings are linked to various health complaints, including cognitive and emotional issues.
• The mechanism by which mold exposure affects brain function and behavior remains unclear.
• Symptoms mimic those of innate immune activation from pathogens, suggesting a similar pathway.

Purpose of the Study:

• To investigate if mold exposure triggers innate immune activation and subsequent neural and behavioral changes.
• To determine if both toxic and non-toxic mold components can induce these effects.
• To explore the correlation between immune activation and cognitive/emotional outcomes.

Main Methods:

• Mice were intranasally administered intact toxic Stachybotrys spores, extracted non-toxic Stachybotrys spores, or a saline vehicle.
• Interleukin-1β immunoreactivity in the hippocampus was measured.
• Neurogenesis, contextual memory, pain thresholds, and auditory-cued memory were assessed in young and aged mice.
• Anxiety-like behaviors were evaluated.

Main Results:

• Intact spores increased hippocampal interleukin-1β.
• Both spore types reduced neurogenesis and impaired contextual memory in young mice.
• Older mice showed decreased pain thresholds and enhanced auditory-cued memory after spore exposure.
• Non-toxic spores increased anxiety-like behavior.
• Hippocampal immune activation correlated with neurogenesis reduction and memory deficits.

Conclusions:

• Innate immune activation is a plausible mechanism linking mold exposure to cognitive and emotional dysfunction.
• Both toxic and non-toxic mold components can induce neural and behavioral changes via immune pathways.
• These findings provide a scientific basis for understanding health complaints associated with moldy environments.