From Tissue to Morphometry: A Step-by-Step Golgi–Cox Workflow for Neuronal and Dendritic Spine Analysis in Adult Mice

Summary

This article describes a step-by-step method for Golgi–Cox staining in adult mice, covering solution preparation, tissue impregnation, cryoprotection, sectioning, development, and mounting. It emphasizes tissue preservation and homogeneous, low-background staining, enabling clear visualization of neuronal morphology. The method labels dendritic arbors and supports quantitative morphometric analysis of dendritic spines.

Abstract

Neuronal morphology analysis in health and disease is fundamental for understanding brain function and for assessing the effects of experimental interventions. Golgi–Cox staining remains a classical, yet highly relevant technique for visualizing complete neuronal arbors and dendritic spines. However, published protocols frequently differ in critical procedural steps and often lack essential methodological details, leading to substantial variability in staining quality and making laboratory standardization time-consuming and challenging. Here, a comprehensive, step-by-step Golgi–Cox protocol for adult mice is presented, encompassing the entire workflow from in vivo handling and tissue processing to imaging and morphometric data extraction. It details practical considerations and common pitfalls that influence impregnation efficiency, section integrity, and signal-to-noise ratio, and provide methodological guidance to improve reproducibility. Overall, this protocol enables reliable visualization and quantitative analysis of whole neurons, dendritic segments, and dendritic spines. It is anticipated that this resource will facilitate the implementation of Golgi–Cox staining with greater consistency, transparency, and technical rigor, while offering a clear framework for adapting the method to diverse laboratory settings.

Introduction

The overall goal of the Golgi–Cox staining method is to enable high-resolution visualization of complete neuronal morphology, including dendritic arbors and dendritic spines, in fixed brain tissue^1,2,3,4. This technique allows detailed structural analysis of individual neurons within complex neural circuits, making it particularly valuable for studies of synaptic plasticity, neurodevelopment, neurodegeneration, and experience-dependent structural remodeling^5,6.

Protocol

Adult female wild-type B6129SF2/J mice (n = 3) were used in this study. However, similar staining can be accomplished using both sexes at the adult stage. All experimental procedures received previous Bioethics Committee approval. (#117.A, Institute of Neurobiology (INb), National Autonomous University of Mexico)

1. Preparation of solutions

CAUTION: Mercuric chloride is highly toxic and corrosive. Handle inside a chemical fume hood while wearing gloves, a lab coat, and eye protection. Dispose of waste in a labeled hazardous waste container. Potassium dichromate and potassium chromate are toxic and ....

Results

Tissue impregnation and sectioning
The Golgi–Cox protocol described here produced reliable and homogeneous neuronal staining in adult mouse brain tissue. After impregnation in Golgi–Cox solution, the brain acquired a characteristic dark golden coloration, indicating successful diffusion of the staining solution throughout the tissue. Vibratome sectioning preserved the structural integrity of neuronal somata and dendritic processes.

Neuronal visualization

Discussion

The Golgi–Cox staining method remains one of the most widely used techniques for visualizing neuronal morphology and dendritic spines in fixed brain tissue^3,4. By impregnating a small, random subset of neurons, this method enables visualization of complete dendritic trees with minimal background staining. In the present protocol, the technique allowed clear visualization of hippocampal pyramidal neurons and their dendritic spines, enabling reliable morphome.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Agarose	Life Technologies	15510-027	CAS 9012-56-6
Ammonia solution 25%	Merck	208380	CAS 1336-21-6. Hazardous.
Anhydrous sodium phosphate dibasic	Sigma-Aldrich	S3264	CAS 7558-79-4
Bright-field Microscope	Nikon	Eclipse Ci
Chromium potassium sulfate	Sigma-Aldrich	243361
Confocal Microscope	Zeiss	LSM 780
Digital balance	Accuris Instruments	W3200-1200
Embedding molds	Merck	E6032	Dimensions: 22x22 mm
Ethanol	Meyer	394
Experimental animals	The Jackson Laboratory	2124-01	B6129SF2/J mouse strain
Gelatin powder	Sigma-Aldrich	G2500
GraphPad Prism Software	GraphPad Software Inc.		Version 8.0.2
ImageJ Fiji Software	U.S. National Institute of Health		version 1.54p, https://imagej.net/software/fiji/downloads
Mercuric chloride	J.T. Baker	2594-01	CAS 7487-94-7. Hazardous.
Microscope Camera	Nikon	DS-Vi1
Microscope objective (10x)	Nikon	93183	Plan 10x/0.25 N.A.
Microscope objective (1x)	Nikon	93180	Plan UW 1x/0.04 N.A.
Microscope objective (20x)	Nikon	93184	Plan 20x/0.40 N.A.
Microscope objective (4x)	Nikon	93182	Plan 4x/0.10 N.A.
Microscope objective (63x)	Zeiss	420782-9900-799	Plan APO 63x/1.4 N.A. oil DIC
Microscope slides	Sigma-Aldrich	S8902
Monohydrated sodium phosphate monobasic	J.T. Baker	3818-05	CAS 10049-21-5
Nail Polish	SINFUL COLORS	BOLD COLOR	Transparent
Permount mounting media	Fisher Scientific	SP15-500
Potassium chromate	Productos Químicos Monterrey	2784	CAS 7789-00-6. Hazardous.
Potassium dichromate	Sigma-Aldrich	207802	CAS 7778-50-9. Hazardous.
PyReconstruct Software	University of Texas, Austin		version 1.19.0, https://github.com/SynapseWeb/PyReconstruct
Sodium chloride	Fermont	24912	CAS 7647-14-5
Sodium thiosulfate	Productos Químicos Monterrey	7291	CAS 7772-98-7. Hazardous.
Sucrose	J.T. Baker (Avantor)	4072-05	66.55° Specific rotation, ACS reagent
Vibratome	Leica Biosystems	VT1200S	SPEED 20 mm/s, AMPL – 0.60 mm
Xylene	CTR Scientific	CTR05128	CAS 1330-20-7. Hazardous.