Biology subjects

Borie, A. M.

Publications and source records attributed to Borie, A. M..

3 recordsLinked to original sources

bioRxiv2021

Social experience alters oxytocinergic modulation in the nucleus accumbens of female prairie voles

Social relationships are dynamic and evolve with shared and personal experiences. Whether the functional role of social neuromodulators also evolves with experience to shape the trajectory of relationships is unknown. We utilized pair bonding in the socially monogamous prairie voles as an example of socio-sexual experience that dramatically alters behaviors displayed toward other individuals. We investigated oxytocin-dependent modulation of excitatory synaptic transmission in the nucleus accumbens as a function of pair bonding status. We found that an oxytocin receptor agonist decreases the amplitude of spontaneous Excitatory Postsynaptic Currents (EPSCs) in sexually naive virgin, but not pair-bonded, female voles, while it increases the amplitude of electrically evoked EPSCs in paired voles, but not in virgins. This oxytocin-dependent potentiation of synaptic transmission relies on the de novo coupling between oxytocin receptor signaling and endocannabinoid CB1 receptor signaling in pair bonded voles. Blocking CB1 receptors after pair bond formation increases the occurrence of a specific form of social rejection - defensive upright response - that is displayed towards the partner but not towards a novel individual. Altogether, our results demonstrate that oxytocins action in the nucleus accumbens is changed through social experience in a way that regulates the trajectory of social interactions as the relationship with the partner unfolds, potentially promoting the maintenance of a pair bond by inhibiting aggressive responses. These results provide a mechanism by which social experience and context shift oxytocinergic signaling to impact neural and behavioral responses to social cues.

neuroscience↗

bioRxiv2019

Control of Social Withdrawal of Mice Deficient for the Autism Gene Magel2 by Restoration of Vasopressin-Oxytocin Dialogue in Septum

Intellectual and social disabilities are common comorbidities in adolescents and adults with Magel2 gene deficiency characterizing the Prader-Willi and Schaaf-Yang neurodevelopmental syndromes. The cellular and molecular mechanisms underlying the risk for autism in these syndromes are unexplored. Here we used Magel2 knockout mice combined with optogenetic/pharmacological tools to characterize disease modifications in the social brain network. We find that the degree of social novelty moderates a dialogue between vasopressin and oxytocin in the lateral septum, a region organizing sequential content of sensory experiences. Social withdrawal of mice lacking Magel2 is alleviated by restoration of dialogue-lead by vasopressin. This preclinical study identifies the collective actions of vasopressin and oxytocin in the lateral septum as a key factor in the pathophysiology.

neuroscience↗

bioRxiv2019

Persistence of learning-induced synapses depends on neurotrophic-priming of glucocorticoid receptors

Stress can either promote or impair learning and memory. Such opposing effects depend on whether synapses persist or decay after learning. Maintenance of new synapses formed at the time of learning upon neuronal network activation depends on the stress hormone activated glucocorticoid receptor (GR) and neurotrophic factor release. Whether and how concurrent GR and neurotrophin signaling integrate to modulate synaptic plasticity and learning is unknown. Here we show that deletion of the neurotrophin BDNF-dependent GR phosphorylation sites (GR-PO4) impairs long-term memory retention and maintenance of newly formed postsynaptic dendritic spines in the mouse cortex after motor skills training. Chronic stress and the BDNF polymorphism Val66Met disrupt the BDNF-dependent GR-PO4 pathway necessary for preserving training-induced spines and previously acquired memories. Conversely, enrichment living promotes spine formation but fails to salvage training-related spines in mice lacking BDNF-dependent GR-PO4 sites, suggesting it is essential for spine consolidation and memory retention. Mechanistically, spine maturation and persistence in the motor cortex depend on synaptic mobilization of the glutamate receptor GluA1 mediated by GR-PO4. Together, these findings indicate that regulation of GR-PO4 via activity-dependent BDNF signaling is important for learning-dependent synapses formation and maintenance. They also define a new signaling mechanism underlying these effects.\n\nSIGNIFICANCE STATEMENTSignal transduction of receptors tyrosine kinase and nuclear receptors is essential for homeostasis. Phosphorylation is one of the currencies used by these receptors to support homeostatic reactions in learning and memory. Here we show that consolidation of learning-induced neuroplasticity is made possible via stress activated glucocorticoid nuclear receptor phosphorylation through the brain-derived neurotrophic tyrosine kinase pathway. Crosstalk between these pathways is specific of cell types and behavioral experience (e.g. learning, stress and enrichment living). Disruption of this response may contribute to the pathophysiology of stress-related disorders and treatment resistance.

neuroscience↗