Early Life Exposure to Deltamethrin Impairs Synaptic Function by Altering the Brain-Derived Extracellular Vesicle...

Area of Science:

• Neuroscience
• Environmental Toxicology
• Molecular Biology

Background:

• Pyrethroid pesticides, including deltamethrin (DM), are linked to neurodevelopmental disorders like ADHD and ASD.
• The precise mechanisms underlying pyrethroid-induced neurotoxicity, particularly concerning brain dysfunction, are not fully understood.
• Brain-derived extracellular vesicles (BDEVs) play crucial roles in intercellular communication within the brain.

Purpose of the Study:

• To investigate whether early-life exposure to deltamethrin (DM) alters brain-derived extracellular vesicle (BDEV) signaling.
• To elucidate the potential role of these altered BDEVs in mediating neurotoxicity and affecting synaptic function.

Main Methods:

• Rodents were exposed to DM at a no observable effect level during early development.
• BDEVs were isolated from exposed and control mice, followed by proteomic analysis to identify differentially expressed proteins (DEPs).
• Functional effects were assessed by injecting labeled BDEVs into naive mice and measuring long-term potentiation (LTP) in hippocampal synapses.

Main Results:

• Proteomic analysis identified 89 DEPs in BDEVs from DM-exposed mice, converging on pathways related to mitochondrial function and synaptic plasticity.
• Injection of BDEVs from DM-exposed mice into naive adult mice abolished hippocampal LTP, a key indicator of learning and memory.
• Exogenous delivery of LRRTM1, a DEP identified in DM BDEVs, disrupted synaptic transmission and impaired LTP.

Conclusions:

• Early-life deltamethrin exposure induces significant alterations in the protein cargo of brain-derived extracellular vesicles (BDEVs).
• Altered BDEV signaling represents a novel mechanism through which DM exerts its neurotoxic effects, impacting synaptic plasticity and cognitive function.
• Targeting BDEV-mediated communication could offer new therapeutic strategies for pesticide-induced neurodevelopmental disorders.