Cservenak, M. | bioRxiv Science

bioRxiv2025

Postpartum enhancement of spatial learning and cognitive flexibility: an IntelliCage study

The transition to motherhood has been shown to result in significant changes in the structure and function of the brain, with particular emphasis on the enhancement of cognitive abilities that are essential for survival. Specifically, in murine models, spatial learning and cognitive flexibility have been identified as critical components of mothering. These abilities facilitate efficient navigation of the environment, resource acquisition, and responsiveness to offsprings needs. While cognitive enhancements during the postpartum period have been observed in various experimental setups, research using long-term data collection with automated monitoring in home cage setup is completely lacking even though it provides a more reliable approach than other experimental procedures. This study aims to address this knowledge gap by systematically examining spatial learning and cognitive flexibility in female mice during the reproductive stages using IntelliCage, with the objective of offering a more comprehensive understanding of maternal cognitive adaptations. Utilising the IntelliCage system, we observed that female mice in the postpartum phase outperformed pregnant and nulliparous females in place learning, reversal learning, and fixed schedule drinking tasks, demonstrating faster adaptation and superior retention of information. These paradigms mirror real-world challenges faced by mothers, such as navigating resources and balancing caregiving with self-maintenance. The enhanced performance demonstrated by the mothers could be attributed to their heightened motivation and cognitive abilities, potentially influenced by substantial hormonal shifts, which have been known to modify neuroplasticity in critical brain regions. The identification of these improvements in maternal behaviour may offer novel insights into the impact of reproductive experiences on brain function, with implications for maternal health and broader cognitive research.

neuroscience↗

bioRxiv2022

A thalamo-preoptic pathway promoting social touch

Social touch is an important form of communication, it is still unknown how it is processed. Here, we discovered a functional role for a neuronal pathway projecting from the posterior intralaminar thalamic nucleus (PIL) to the medial preoptic area (MPOA) in controlling social contact. Neurons in the PIL and the MPOA were activated by physical contact between female rodents and also by chemogenetic stimulation of PIL neurons. Chemogenetic stimulation of PIL neurons tagged by social contact experience increased direct physical interactions between familiar female rats without affecting other forms of social behavior. Furthermore, selective stimulation of the PIL-MPOA pathway, and the local activation of PIL terminals within the MPOA, elevated direct social contact between the animals suggesting the role of pathway-specific activated cell assemblies. Neurons projecting from the PIL to the MPOA contain the neuropeptide parathyroid hormone 2 (PTH2). The expression of the peptide was induced by social housing, the presence of PTH2 receptor was identified in MPOA neurons, and local injection of PTH2 increased the firing rate of identified preoptic area GABAergic neurons via the PTH2 receptor suggesting that PTH2 acts as a neurotransmitter in the PIL-MPOA pathway. We also found a homologous PIL to MPOA neuronal pathway in the human brain. Altogether, we discovered a direct thalamo-preoptic pathway, which bypasses the cerebral cortex and controls social touch. This pathway originates in neurons expressing PTH2, a neuropeptide recently shown in fish to respond to the social environment. These observations provide evidence for common evolutionary-conserved PTH2-containing social-touch specific engram circuits.

neuroscience↗