Biology subjects

Aspesi, D.

Publications and source records attributed to Aspesi, D..

3 recordsLinked to original sources

bioRxiv2026

Postpartum resource scarcity reshapes maternal care, offspring prioritization, and the steroid-sensitive medial preoptic area

Parental care requires balancing offspring needs with environmental constraints, yet how resource scarcity alters the organization of maternal responses remains poorly understood. Here, we examined maternal behavior, offspring prioritization, and steroid receptor-associated extracellular matrix organization in postpartum rats exposed to limited bedding and nesting (LBN) or control conditions with ample nesting materials. LBN increased pup-directed and reduced self-directed behaviors but also increased behavioral entropy, a measure of behavioral fragmentation, indicating less predictable caregiving sequences. LBN dams preferentially retrieved male pups first, whereas control dams preferentially retrieved females first. LBN also increased the proportion of pup-investigation time directed toward males compared with controls. In offspring on postnatal day 10, corticosterone was elevated in female but not male LBN pups, a pattern that paralleled the maternal male bias. To identify associated neurobiological changes, we assessed steroid receptors and extracellular matrix organization in the medial preoptic area (mPOA), a key region for maternal behavior. LBN increased numbers of estrogen receptor (ER)- and androgen receptor (AR)-immunoreactive cells, reduced perineuronal net (PNN) abundance, and decreased receptor-positive cell enwrapment. Because PNNs constrain structural plasticity, these findings suggest that the postpartum environment alters the organization of steroid receptor-associated extracellular matrix, potentially modulating experience-dependent plasticity in neurosteroid-sensitive circuits. In sum, LBN increases the levels of maternal engagement while reshaping its temporal organization and allocation, accompanied by selective remodeling of steroid-sensitive preoptic architecture. Therefore, maternal adaptation to adversity may be better understood as changes in caregiving allocation strategies rather than a simple gain or loss of maternal care.

neuroscience↗

bioRxiv2025

Sex differences in the neural circuitry of aggression

The social behavior neural network (SBNN) is a circuit composed of reciprocally connected limbic structures that regulate a range of social behaviors, including aggression. Although both males and females of many species display aggressive behavior, studies of the neural circuitry underlying aggression have focused almost exclusively on males. In the present study, we investigated sex differences in neuronal activation of the neural circuitry controlling aggression in Syrian hamsters (Mesocricetus auratus). We employed c-Fos immunohistochemistry to quantify neuronal activation following aggressive encounters between same-sex male and female dyads. Animals were tested in their home cage either alone (n=7 per sex) or with a same-sex, non-aggressive intruder (n=7 per sex) for 10 minutes. Our data revealed substantial sex differences in the neuronal activation of the SBNN following aggression. In some regions, neuronal activity changed in opposite directions in males and females compared to controls (e.g., posterior lateral septum), while in others, there was a change in neuronal activation in only one sex (e.g., medial amygdala). These findings support the hypothesis that the neural circuitry regulating aggression exhibits marked sexual differentiation. HighlightsO_LIThe neural circuitry regulating aggression was differentially activated in males and females following aggressive encounters C_LIO_LISeveral brain regions exhibited opposite patterns of activation in males and females following aggression C_LIO_LIOnly the BNST had the same pattern of changes in neural activity in males and females following aggression C_LI

neuroscience↗

bioRxiv2025

Comparative gene editing reduces dopamine receptor levels across rodent species

Translational challenges in neuroscience originate from species-specific differences that limit the generalizability of experimental findings. Comparative approaches can help distinguish conserved from species-specific mechanisms, but their application has been limited by the lack of molecular tools beyond traditional model organisms, complicating direct comparisons of conserved and divergent mechanisms of neural function. This gap is particularly evident for the dopaminergic system, a key regulator of motivated behaviors across species and the principal pharmacological target for current psychotherapies. Building on our recent development of comparative gene editing, we here present an adeno-associated virus-mediated CRISPR/Cas9 strategy to reduce in vivo dopamine receptors D1 and D2 levels across the rodent phylogeny. Using this approach, we achieved specific reduction of receptor levels in three rodent species (house mouse, prairie vole, and Syrian hamster), which we demonstrate with radioactive ligand binding assays. This toolkit expands the reach of comparative gene editing approaches, enabling functional investigation of the dopaminergic system across rodent species. Thereby, it supports comparative neuroscience by facilitating the identification of conserved versus species-specific neural mechanisms with enhanced translational potential.

neuroscience↗