Transcriptionally defined amygdala subpopulations play distinct roles in innate social behaviors

Social behaviors are innate and supported by dedicated neural circuits, but the molecular identities of these circuits and how they are established developmentally and shaped by experience remain unclear. Here we show that medial amygdala (MeA) cells originating from two embryonically parcellated developmental lineages have distinct response patterns and functions in social behavior in male mice. MeA cells expressing the transcription factor Foxp2 (MeAFoxp2) are specialized for processing male conspecific cues and are essential for adult inter-male aggression. By contrast, MeA cells derived from the Dbx1 lineage (MeADbx1) respond broadly to social cues, respond strongly during ejaculation and are not essential for male aggression. Furthermore, MeAFoxp2 and MeADbx1 cells show differential anatomical and functional connectivity. Altogether, our results suggest a developmentally hardwired aggression circuit at the MeA level and a lineage-based circuit organization by which a cell’s embryonic transcription factor profile determines its social information representation and behavioral relevance during adulthood.

For all statistical analyses, confirm that the following items are present in in the figure legend, table legend, main text, or or Methods section.

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Björn O. O. Schröder Mar 22, 2024 No No software was used for data collection.
Amplicons generated during bacterial 16S sequencing were quality filtered using Fastx (http://hannonlab.cshl.edu/fastx_toolkit/index.html) and sequence quality assessed using FastQC (http://www.bioinformatics.babraham.ac.uk/projects/fastqc). Analysis of of the human and mousederived 16S amplicon sequences was performed using the QIIME2 (version 2022.8)pipeline and R (version 4.1.3)in in R Studio (RStudio Team, version 2022.07.2).Sequences were clustered into ASVs using the SILVA classifier (version 138).DADA2 was used to to generate the feature table and published R scripts have been used for further data analysis, as as described in in the methods section.Statistical analyses have been performed with GraphPad Prism (Versions 8/9).The code for 16S data analyses is is available at at https://doi.org/10.5281/zenodo.10848038.

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The human data and stool samples that have been collected for a previously published study are available under restricted access due to data privacy laws and can be requested through the enable cluster (skurk@tum.deFor all mouse experiments mice were randomly allocated into experimental groups.The investigators were not blinded to allocation during experiments and outcome assessment.Microbiota transplantation from human volunteers into mice to investigate mucus function on viable tissue is a pioneering approach and thus no robust power calculation could be made before the experiments.Based on experience from mouse-to-mouse microbiota transplantation (Ref.30) we calculated with group averages of 2.2 and 0.9, alpha = 0.05 and a power of 80%, resulting in 8-9 mice per group for the transplantation.For other experiments we pre-determined the number of mice based on previous experiments (Ref 30) with similar bacterial treatments that were able to detect statistically significant differences.
No data were excluded, except for the mucus growth rate and all related data from one mouse in the HF-Chow group, due to rupture of the colonic tissue during the measurement.
All recorded data are reported in the manuscript.Biological replicates were used, as indicated in individual data points in all figures.
Mice were randomly allocated to either group to best match age and sex.In most cases, mice were housed in groups of 3-4 mice per cage.Analysis of mouse groups was alternated between groups during the termination day to exclude any circadian and/ or reagent bias.Human participants for the stool sample transplantation were selected based on their metabolic parameters and shifts in microbiota compositon from the fiber intervention group.The selection/ranking of the donors is described in the methods section.For other experiments the different groups were always analysed together (e.g.qPCR, MiSeq) to prevent any influence of reagents/equipment.Metabolite stimulation of colonic tissue was carried out from the same mice for treatment and control, and proximal/distal part of the distal colon were alternated between treatments.
Mucus measurements of the human FMT, histology analyses and metabolomics were performed blinded.Other experiments were analyzed ). Bacterial 16S rDNA gene sequencing data from the human cohort have been deposited previously in the European Nucleotide Archive under the accession code PRJNA701859 [https://www.ebi.ac.uk/ena/browser/view/PRJNA701859].Bacterial 16S rDNA data from this study have been deposited under the accession code PRJEB57076 [https://www.ebi.ac.uk/ena/browser/view/PRJEB57076].Metabolomics data and all raw data generated in this study are provided in the Source Data file.No human participants were recruited for this study.Stool samples from human donors were obtained from a previously published clinical trial (DRKS00013058).For this present study we ranked the 74 healthy participants (34 men and 40 women, aged between 40-65 years) of the intervention group based on their metabolic improvements and shifts in gut microbiota composition.Details about the ranking and sex distribution of the cohort are described in the manuscript (if relevant), or in the previously published study (Ref 32).The best responders were 4 women and 1 man.No data on race, ethnicity or other socially relevant groupings were used in this study.
Population characteristics are described in detail in Brandl et al. (Ref 32): https://doi.org/10.3389/fnut.2022.816299n/a Ethical Committee of the Faculty of Medicine of the Technical University of Munich (approval no.201/17S)