Sex-dependent long-term effects of prepubescent stress on the posterior parietal cortex

Repeated exposure to multiple concurrent stressors alters visual processing in the adult posterior parietal cortex

“…Following ten consecutive days of RMS, mice were sacrificed and their brains processed for immunohistochemistry as previously described ( Libovner et al, 2020 ; Fariborzi et al, 2021 ). Briefly, mice were transcardially perfused with phosphate buffered saline (PBS) followed by 4% paraformaldehyde (PFA) in PBS.…”

“…Confocal images of immunostained tissue were collected on a LSM700 Confocal Microscope (Zeiss) located in the University of California, Irvine Optical Biology Core. The PPC was identified as described previously ( Libovner et al, 2020 ; Fariborzi et al, 2021 ), and a full column of the posterior parietal cortex was tiled (3x10) at 1x zoom (0.2 μm pixel size) using a 63× oil-immersion objective. Fluorescence was excited via 488 nm, 561 nm, or 640 nm laser lines and emissions were directed into PMT through a beam splitter and filtered for minimal spectral overlap: 410–604 nm for AlexaFluor488, 490–560 nm for Alexafluor555, and 643–700 nm for Neurotrace640.…”

“…To quantify synapse density, a 100 μm 2 area was randomly selected form each layer of the PPC column. Synaptic puncta were counted using unbiased, automated batch processing in CellProfiler ( Lamprecht et al, 2007 ), as described in ( Libovner et al, 2020 ; Fariborzi et al, 2021 ). Synapse densities were expressed as the number of puncta per 100 μm 2 .…”

“…The PPC is a higher order visual region, often associated with multimodal processing ( Whitlock, 2017 ), attention ( Buschman and Miller, 2007 ), working memory ( Suzuki et al, 2022 ), and decision making ( Zhou and Freedman, 2019 ). Previous work indicates that in adolescent mice, repeated stress exposure disrupts synaptic connectivity of the PPC ( Libovner et al, 2020 ; Fariborzi et al, 2021 ). However, the impact of prolonged stress exposure during adulthood on parietal function is currently unknown.…”

Rethinking stress resilience

“…Sex differences in stress responses are well established [76][77][78][79]. The majority of resilience substrates identified to date have been studied and identified in male rodents.…”