Oxytocin and vasopressin within the ventral and dorsal lateral septum modulate aggression in female rats

In contrast to male rats, aggression in virgin female rats has been rarely studied. Here, we established a rat model of enhanced aggression in females using a combination of social isolation and aggression-training to specifically investigate the involvement of the oxytocin (OXT) and arginine vasopressin (AVP) systems within the lateral septum (LS). Using neuropharmacological, optogenetic, chemogenetic as well as microdialysis approaches, we revealed that enhanced OXT release within the ventral LS (vLS), combined with reduced AVP release within the dorsal LS (dLS), is required for aggression in female rats. Accordingly, increased activity of putative OXT receptor-positive neurons in the vLS, and decreased activity of putative AVP receptor-positive neurons in the dLS, are likely to underly aggression in female rats. Finally, in vitro activation of OXT receptors in the vLS increased tonic GABAergic inhibition of dLS neurons. Overall, our data suggest a model showing that septal release of OXT and AVP differentially affects aggression in females by modulating the inhibitory tone within LS sub-networks.


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All studies must disclose on these points even when the disclosure is negative. Sample size was determined to be adequate based on the magnitude and consistency of measurable differences between groups and/or experimental conditions. Group sizes were estimated (according to "G*POWER" and 2-sided non-parametric test; ANOVA and posthoc test, or U-test according to Wilcoxon-Mann-Whitney) .Biological variability corresponding to behavioral variability is between 20-25% was also taken in consideration when determining the group sizes.
Only anatomical outliers in stereotaxic cannula implantation or animals who did not show viral infection were excluded from analyses. For the electrophysiological experiments, leaky cells with a holding current beyond~-30 pA were not further used for experimentation, meaning that they did not receive pharmacological treatment. See methods page 1-20 All experiments included in the manuscript were performed in different cohorts. The data in figure 1, for example, was performed in three different cohorts demonstrating replication and homogenous effects of isolation and training although the intensity of aggression differed between cohorts. Moreover, all cohorts tested for pharmacological experiments showed homogenous effects of the drug although the baseline levels of aggression differed from one cohort to the other. I.c.v. experiments were performed in 2 cohorts of animals (except AVP experiment which was performed in 3 cohorts). Local infusions and MD were performed in 2 different cohorts except GH dLS V1aR antagonist infusion which was performed only once. Opto and chemogenetics experiments were performed in a single cohort. Again we reinforce here that our isolation plus training protocol was able to enhance aggression in all the cohorts evaluated in this manuscript although the absolute levels of aggression differed depending whether the animals had surgery or not for more information please see methods pages 1-20 and 1st rebuttal letter answer to reviewer #1.
For pharmacological experiments in highly aggressive females, rats were divided into the respective VEH or treatment group based on their average aggression data from FIT 3. Group-housed animals were randomized in different groups. All animals used in one group came from different litters in order to increase the diversity within a group. See methods 1-20 Blinded data collections was done when possible. However, as V.E.M.O. conducted most of the experiments on his own blinded data collection for pharmacological, as well as MD and neural activity experiments was not possible. However all the data was analyzed by an observer blinded with respect to groups and treatments. See methods 1-20 All the antibodies used can be found in supplementary table 5 Information on validation of anti-oxytocin (PS38, mouse) antibody is reported in previous publications from our lab, please see methods and Dr. Harold Gainer (NIH, Bethesda) papers. All other antibodies validations are available on the description files of the respective companies websites. For more information please check our references in the method section. Specifically, anti-pERK antibody and streptavidin staining have been previously used and validated in our lab, please see methods and references. Anti-ERa and Anti-Somatostatin antibodies were validated by the respective companies in cell culture for IHC. Moreover, without primary and without secondary controls were ran in parallel to the experimental animals to check for antibody specificity.