Whole Central and Peripheral Nervous System Mice Dissection
Summary
Here, we present a protocol to complete the dissection of central and peripheral nervous systems of mice. The dissected tissues are further analyzed in downstream applications, such as taking gross pictures or histology.
Abstract
Animal models represent the workhorse of the neuroscience field. Despite this, today, there is still no step-by-step protocol to dissect a complete rodent nervous system, nor is there a complete schematic representing it that is freely available. Only methods to harvest the brain, the spinal cord, a specific dorsal root ganglion, and the sciatic nerve (separately) are available. Here, we provide detailed pictures and a schematic of the central and peripheral murine nervous system. More importantly, we outline a robust procedure to perform its dissection. The 30 min pre-dissection step allows isolating the intact nervous system within the vertebra with muscles free of viscera and skin. A 2-4 h dissection follows it under a micro-dissection microscope to expose the spinal cord and the thoracic nerves, and finally peel the whole central and peripheral nervous system off the carcass. This protocol represents a significant step forward in studying the anatomy and pathophysiology of the nervous system globally. For example, the dissected dorsal root ganglions from a neurofibromatosis type I mice model can be further processed for histology to unravel changes in tumor progression.
Introduction
The overall goal of this method is to isolate a mouse's central and peripheral nervous system in one piece. There is currently no protocol to dissect the whole nervous system of a rodent to study it on a global level. Neuroscientists typically use the sciatic nerve as a surrogate for any peripheral nerve1, and the L3 to L5 ganglions2 as a surrogate for any ganglions. Using these methods, it is impossible to conclude if the results are specific to the particular nerve/ganglion. As it is known that at least some nerve pathologies do not affect all nerves and ganglions equally3,4,5, one must develop a technique to allow the isolation of the complete rodent nervous system to study it globally.
Over the years, we have developed and refined a method to dissect the complete central and peripheral nervous systems of mice. The first step is essentially a gross dissection of the mice in preparation for the micro-dissection steps under the dissection microscope. In steps 2 to 4, the spinal cord and the thoracic nerves are exposed, the brain is dissected, and the whole spinal cord and peripheral nerves are peeled off the carcass.
This method is powerful when coupled to imaging or histology to document any macroscopic or microscopic change6,7,8,9. Neuroscientists interested in surveying global change or conducting non-hypothesis-driven experiments should use this method to survey the global nervous system.
Protocol
Representative Results
Discussion
To prevent the muscles and nerves from drying out, the carcass should be soaked in PBS every 10 min. When dislocating the lower limbs (step 1.12.6), it is important to always have the sciatic nerve plexus and L2 in sight to avoid damaging/tearing it. When dissecting the brain (step 1.14.4), it is critical to avoid going too deep so as not to damage the brain. When dissecting the dorsal root ganglions and peripheral nerves in general, it is critical to use high-quality (not damaged) Dumont mini-forceps to avoid damaging t…
Divulgations
The authors have nothing to disclose.
Acknowledgements
JPB is a FRSQ J1 research scholar and a recipient of the Early Investigator Research Award from the US Department of Defense. LQL holds a Career Award for Medical Scientists from the Burroughs Wellcome Fund and the Thomas L. Shields, M.D. Professorship in Dermatology.
Materials
| Dumont mini-forceps | Fine Science Tools | #11200-10 | |
| Extra Bonn scissors | Fine Science Tools | #14084-08 | |
| Formalin 10% | Fischer Scientific | #22-046-361 | |
| PBS 1x | BioShopCanada | #PBS404.500 | |
| Standard anatomical forceps | Fine Science Tools | #91100-12 | |
| Surgical scissors | Fine Science Tools | #140001-12 | |
| Vannas spring scissors | Kent Scientific | #INS600124 |
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