Mass Spectrometry Imaging Deciphers Enantioselective Lipid Dysregulation and Cognitive Memory in Honey Bee Brains Exposed to Chiral Dinotefuran

Honey bees serve as crucial pollinators, maintaining ecosystem integrity through supporting wild plant reproduction, ensuring food security, and preserving biodiversity. Neonicotinoid insecticides, despite their agricultural ubiquity, remain highly controversial in global agriculture due to their detrimental effects on bee populations. While chiral neonicotinoids are promising for mitigating pollinator risks through stereospecific toxicity disparities, critical knowledge gaps persist regarding their enantioselective effects on the learning and memory behaviors of bees. Here, we developed high-resolution mass spectrometry imaging (MSI) combined with lipidomics and transcriptomics to visualize dinotefuran enantiomer-associated lipid dysregulation in functional microregions of bee brains at metabolic and transcriptional levels for the first time. Various lipid markers with a microregion-specific distribution could be clearly distinguished within tiny bee brains. Unexpectedly, exposure to the highly toxic <i>S</i>-(+)-dinotefuran enantiomer results in less deterioration of learning and memory behaviors of bees despite its greater impact on their survival. Further, we present correlative evidence linking enantioselective damage to learning and memory behaviors with glycerophospholipids within bee brain microregions, highlighting their key roles in strengthening immune activation. These findings promote our understanding of bee brain defense mechanisms against chiral neonicotinoids, offering avenues to improve risk assessments of neonicotinoids for safeguarding pollinator health.