Oxytocin and dopamine receptor expression: Cellular level implications for pair bonding

Oxytocin (Oxtr) and dopamine (Drd1, Drd2) receptors provide a canonical example for how differences in neuromodulatory receptors drive individual and species-level behavioral variation. These systems exhibit striking and functionally-relevant differences in nucleus accumbens (NAc) expression across monogamous prairie voles (Microtus ochrogaster) and promiscuous meadow voles (Microtus pennsylvanicus). However, their cellular organization remains largely unknown. Using multiplex in situ hybridization, we mapped Oxtr, Drd1, and Drd2 expression in sexually naïve and mate-paired prairie and meadow voles. Prairie voles have more Oxtr+ cells than meadow voles, but Oxtr distribution across dopamine-receptor cell class was similar, indicating a general upregulation rather than cell class bias. Oxtr was enriched in cells that express both dopamine receptors (Drd1+/Drd2+) in prairie voles, suggesting these cells may be particularly sensitive to oxytocin. We found no species or pairing-induced diff..., Images were analyzed using Fiji ImageJ software (version 2.14.0/1.54f). Images were split into four channels:

Channel 0 = DAPI
Channel 1 = Drd1
Channel 2 = Drd2
Channel 3 = Oxtr

Regions of interest (ROIs) outlining DAPI-stained nuclei were automatically generated in Fiji ImageJ. Thresholds for DAPI nuclear staining were manually established to eliminate background and accurately overlay nuclei.
DAPI Mask Validation

Accuracy was verified in 10% of images (one per animal) by comparing experimenter-counted vs. automatic nuclei counts.
Counts differed by ≤5%, supporting the reliability of automatic ROI generation.

Signal Detection & Quantification

The DAPI mask overlay was applied to Drd1, Drd2, and Oxtr images (Fig. 1C).
A white top-hat transformation enhanced contrast, improving bright feature detection.
Collected signal data included:

ROI number (nucleus number)
Minimum, mean, and maximum intensity values
% area (for both 16-bit and 8-bit data)

Data Processing & Analysis..., # Oxytocin and dopamine receptor expression: Cellular Level implications for pair bonding

Dataset DOI: [10.5061/dryad.s1rn8pkk3](10.5061/dryad.s1rn8pkk3)

## Description of the data and file structure

**Data Description**

This dataset was collected from four cohorts of voles:

* Sexually naive prairie voles (NP)
* Sexually naive meadow voles (NM)
* Pairbonded prairie voles (PP)
* Paired meadow voles (PM)

Data was obtained through microscopy image analysis using Fiji ImageJ software.

**Data Collection & Processing**

**Microscopy Analysis**

* DAPI masks were generated using the Analyze Particles function in Fiji ImageJ. Each region of interest (ROI) represents a nucleus.
* The presence or absence of transcript was assessed for each ROI across three channels: D1DR (Drd1), D2DR (Drd2), and OXTR (Oxtr).
* Data collected per ROI included:
* ROI number
* ROI area
* Mean, minimum, and maximum gray values
* Percent area covered by pixels

**Oxtr Puncta Quantification**

* Oxtr pun...,