DOI: 10.5061/dryad.3r2280grv
title: Data from: An evolutionary loss of parental care in stickleback is associated with differences in the activity, but not the number, of neuropeptidergic neurons in the preoptic area

description: How can extensive diversity in social behaviour arise when behaviours
 often depend on shared neural and hormonal mechanisms? In this study, we
 discriminated between two ways conserved neural mechanisms might evolve to
 generate differences in social behaviour: number or activity of neurons.
 We compared two recently diverged ecotypes of threespine stickleback
 (Gasterosteus aculeatus) in which males differ in the parental care they
 provide. We quantified the number and activation of two types of
 neuropeptidergic neurons in the preoptic area that affect parental care in
 other species, galanin and oxytocin. Ecotypes did not differ in the
 overall activation of the preoptic area or the number of galanin and
 oxytocin neurons. However, ecotypes did differ in the activation of
 galanin and oxytocin neurons. Activation of these neurons changed across
 reproductive stages in the caring but not the non-caring ecotype,
 suggesting that changes in the activation of these specific preoptic
 neurons are required to transition to parenting. Our study provides
 evidence that diversity in social behaviour can be generated via changes
 in the activation of specific preoptic neuropeptidergic neurons.
description: # An evolutionary loss of parental care in stickleback is associated with
 differences in the activity, but not the number, of neuropeptidergic
 neurons
 [https://doi.org/10.5061/dryad.3r2280grv](https://doi.org/10.5061/dryad.3r2280grv) ## Description of the data and file structure Brains were collected from male threespine stickleback of two ecotypes - whites and commons - that differ in parental behaviour. Brains were sectioned and stained via double-label immunohistochemistry (IHC) to quantify the number of preoptic neurons labelled with pS6 (a marker for activated neurons), galanin (Gal), oxytocin (OXT), pS6 and Gal, and pS6 and OXT at three reproductive stages. Behavioural data were also collected on the same individuals to determine if reproductive behaviours were correlated with the activation of Gal or OXT neurons. ### Files and variables #### File: metadata.csv **Description:** This file contains unique identifiers for each male and information about which reproductive stage and ecotype each male belonged to. Each row represents one male. ##### Variables * male_id: a unique identifier for each male, used to associate the metadata with behavioural data (IHC_behavior.csv) * fish_id: a unique identifier for each male, used to associate the metadata with neural data (series_1.csv and series_2.csv) * stage: describes the reproductive stage when each male's brain was collected - *nesting, 0 dpf* (dpf=days post-fertilization), *4 dpf* * ecotype: males belonged to either the *white* non-caring ecotype or the *common* caring ecotype #### File: series\_1.csv **Description:** This file contains unique identifiers for each male and data collected on brain sections included in series 1, which was stained for Gal and pS6. Each row represents one brain section within the POA. ##### Variables * fish_id: a unique identifier for each male, used to associate this file with the metadata * gal_count: the number of Gal-positive neurons counted in each brain section * ps6_count: the number of pS6-positive (i.e., activated) neurons counted in each brain section * gal_ps6_count: the number of Gal neurons that were co-labelled with pS6 (i.e., activated Gal neurons) counted in each brain section * polygon_area_mm2: the size (area) of the POA in each section represented in millimetres squared #### File: series\_2.csv **Description:** This file contains unique identifiers for each male and data collected on brain sections included in series 2, which was stained for OXT and pS6. Each row represents one brain section within the POA. ##### Variables * fish_id: a unique identifier for each male, used to associate this file with the metadata * oxt_count: the number of OXT-positive neurons counted in each brain section * oxt_ps6_count: the number of OXT neurons that were co-labelled with pS6 (i.e., activated OXT neurons) counted in each brain section * polygon_area_mm2: the size (area) of the POA in each section represented in millimetres squared #### File: IHC\_behavior.csv **Description:** This file contains unique identifiers for each male and data from behavioural observations on each male. Each row represents one behavioural observation. Some males were observed more than once (see below for more details). ##### Variables * male_id: a unique identifier for each male, used to associate this file with the metadata * trial_type: four trial types are included, which align with the reproductive stages at which males were sacrificed (described in the metadata) * *nesting* - behaviours observed in males assigned to the nesting stage * *courtship* and *post-spawn* - behaviours observed pre- and post-mating, respectively, in males assigned to the 0 dpf stage * *4 days post-spawn* - behaviours observed in males assigned to the 4 dpf stage * length_of_trial_s: duration of the behavioural observation in seconds, most trials were 900 s long but courtship trials varied in length depending on how quickly the the male mated * time_fanning_s: time male spent fanning his pectoral fins in seconds, this behaviour is shown across contexts and was therefore measured for all values of trial_type ## Code/software All code was run in R version 4.3.1 (2023-06-16). Code for data analysis and visualisation is provided.