Extraction and Dissection of the Domesticated Pig Brain

Summary

This protocol details the technique for removal of the pig brain in its entirety and dissection of several brain regions commonly studied in neuroscience.

Abstract

Use of the pig as a preclinical and translatable animal model has been well-documented and accepted by research fields investigating cardiovascular systems, gastrointestinal systems, and nutrition, and the pig is increasingly being used as a large animal model in neuroscience. Furthermore, the pig is an accepted model to study neurodevelopment as it displays brain growth and development patterns similar to what occurs in humans. As a less common animal model in neuroscience, surgical and dissection procedures on pigs may not be as familiar or well-practiced among researchers. Therefore, a standardized visual protocol detailing consistent extraction and dissection methods may prove valuable for researchers working with the pig. The following video showcases a technique to remove the pig brain while keeping the cortex and brainstem intact and reviews methods to dissect several commonly investigated brain regions including the brainstem, cerebellum, midbrain, hippocampus, striatum, thalamus, and medial prefrontal cortex. The purpose of this video is to provide researchers with the tools and knowledge necessary to consistently perform a brain extraction and dissection on the four-week-old pig.

Introduction

The pig has been well documented and accepted as a translatable animal model for research in cardiovascular systems¹, gastrointestinal systems², nutrition^3,4, diabetes⁵, toxicology⁶, and surgical techniques⁷. Use of the pig in neuroscience is beginning to increase, as PubMed searches for the keywords "swine brain animal model" result in four-times more results from 1996-2005 than the preceding 10 year period⁸, and even more results at present. A primary reason ....

Protocol

Procedures involving animal subjects have been approved by the Institutional Animal Care and Use Committee (IACUC) at the University of Illinois at Urbana-Champaign

NOTE: Prior to euthanasia, the pig was anesthetized via intramuscular injection with a combination of telazol:ketamine:xylazine (50.0 mg of tiletamine HCl plus 50.0 mg of zolazepam HCl reconstituted with 2.50 mL of ketamine HCl (100 g/L) and 2.50 mL of xylazine (100 g/L) and administered at 0.06 mg/kg BW). Once anesthetized, the pi.......

Discussion

The techniques described herein were designed for pigs approximately 4 weeks of age. It is critical to perform these steps immediately after the pig has been humanely euthanized to ensure the integrity of brain tissue structure is maintained, especially when considering subsequent biochemical assays. It is helpful to use an atlas or fiber¹⁶ dissection guides when first learning the techniques. It is recommended that the experimenter practice several brain extractions and dissections prior to obtai.......

Materials

Name	Company	Catalog Number	Comments
#22 Scalpel Blades for #4 Handles	Ted Pella, inc.	549-4S-22
11 1/2" Satterlee Bone Saw	Leica Biosystems	38DI13425
5 1/2" Skull Breaker with Chisel End (Meat Hook)	Leica Biosystems	38DI37636
5-inch Heavy Duty Workshop Bench Vise	Pony	29050
Butcher Knife 25cm	Victorinox	5.7403.25	Sharpen before use
CM40 Light Duty Drop Forged C Clamps	Bessey	00655BC3120
Diamond Hone Knife Shaper	Chef’s Choice	436-3
Shandon Stainless-Steel Scalpel Blade Handle #4	ThermoScientific	5334
Tissue Forceps	Henry Schein	101-5132
Vinyl Dissecting pad	Carolina	629006