Regional glial alterations associated with systemic PCPV2 exposure in adult rats

PCPV2 is a toxic protein from the perivitelline fluid of the invasive freshwater snail Pomacea canaliculata. Although neurological effects have been reported following systemic administration of purified PcPV2, its effects on the mammalian brain remain poorly understood. Our previous behavioral analyses showed that a single intraperitoneal administration of PcPV2 (250 µg/kg) induced a decrease in body weight and acute and persistent alterations in exploratoryand species-typical behaviors, motor performance, and cognitive function, without detectable changes in cortical oxidative stress markers. To investigate potential cellular mechanisms underlying these effects, we evaluated hippocampal immature neurons, hilus volume, and region-specific glial changes. Iba1 and GFAP immunoreactivity were assessed to evaluate microglial and astrocytic changes, respectively, in hippocampal CA1, CA3 and dentate gyrus and perirhinal cortex. PcPV2 exposure did not alter the number of DCX+ immature neurons or hilus volume. However, Iba1+ microglia showed morphological changes in CA3, with decreased circularity and solidity, suggesting a region-specific alteration in microglial phenotype. Further characterization of microglial and astrocytic responses is ongoing. This approach may help determine whether PcPV2 exposure is associated with region-specific glial changes and identify potential biological substrates underlying the behavioral alterations.