Name: Development of a Neonatal Rat Model for Brachial Plexus Birth Injury (Video) | JoVE Journal
Uploaded: 2026-03-27T15:00:00.000+00:00
Duration: 9 min 42 s
Description: Learn to develop a reproducible neonatal rat model for studying brachial plexus birth injury using Sprague Dawley pups. This protocol enables investigation of injury mechanisms and therapeutic interventions.

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5 minutes

We gratefully acknowledge Dr. Felicia Boynton, DVM, and Dr. Chris Gow, DVM, for their expert guidance on rat pup and rat dam handling, perioperative and postoperative care of the rat pups, which contributed substantially to the optimization of this protocol.

All animal procedures were performed with approval of the Institutional Animal Care and Use Committee (IACUC A0007335). The technique was performed in 15 Sprague-Dawley rat pups to assess feasibility and long-term functional outcomes.
1. Animal husbandry
<ol>
	<li>House a multiparous pregnant Sprague Dawley rat (gestational age: 14 days) in a breeder box (1354&#160;cm2) containing cellulose paper-based bedding, enriched with nesting material and cage enrichments; maintain room temperature at 21 &#176;C with relative humidity at 28% and a 12:12 h light/dark cycle. Provide rat chow and water ad libitum.</li>
	<li>Clean cages weekly; leave the cage undisturbed for 48 h after delivery of the pups. To promote habituation and reduce stress, provide auditory reassurance through gentle handling and speech. During late gestation, ensure the dam is habituated to the investigator through daily gentle handling and olfactory conditioning by placing ethanol and betadine-scented cotton balls into the dam&#39;s cage.</li>
	<li>After delivery of the pups, place treats in the cage without disturbing the dam for 48 h or opening the cage.</li>
</ol>
2. Material preparation
<ol>
	<li>Ensure all required surgical instruments are prepared before the surgery (see the Table of Materials). Sterilize all surgical supplies using a steam autoclave at 121 &#176;C for 1 h.</li>
	<li>Create a surgical bed out of expanded polystyrene. (Figure 1)</li>
</ol>
3. Surgical preparation
<ol>
	<li>Perform surgeries on rat pups at an age of 5 days old [range between 3 and 9 days].</li>
	<li>Induce anesthesia by placing the rat in an induction chamber with 2% isoflurane in 2 L/min oxygen until the medium-to-deep anesthetic stage is achieved. Confirm adequate anesthesia with a gentle toe pinch using forceps. Place the rat pup on a prewarmed heating pad. Maintain anesthesia on 1.5-2% isoflurane in oxygen and monitor respiratory rate continuously.</li>
	<li>Determine the appropriate dosage of analgesia based on the pup&#39;s weight. Administer buprenorphine extended release (1 mg/kg s.c.) to manage pain.</li>
	<li>Prepare an aseptic surgical site by applying three alternating scrubs of betadine and ethanol.</li>
	<li>Position the anesthetized pup in a prone position on the premade surgical bed with the nose and mouth placed securely in the isoflurane vaporizer nose cone (Figure 1B).</li>
	<li>To minimize movement during the procedure, tape the head of the rat pup onto the isoflurane vaporizer and cover the lower part of its body, just below the upper extremities, withfoil.</li>
</ol>
4. Surgical approach to the brachial plexus
<ol>
	<li>Create a 5 mm skin incision using a No. 11 blade, beginning at the base of the skull and extending caudally to the C7-T1 vertebral transition (Figure 1C).</li>
	<li>Carefully cauterize superficial arteries while avoiding skin edges.</li>
	<li>Perform blunt dissection until the trapezius muscle is reached.</li>
	<li>Dissect through the trapezius and underlying rhomboid and levator scapulae muscles using cauterization. Place the cautery forceps perpendicular to the tissue to avoid thermal injury to the skin edges.</li>
	<li>Gently retract the superior angle of the scapula to expose the brachial plexus. Identify and isolate the brachial plexus via blunt dissection (Figure 1D and Figure 2A).</li>
	<li>Cauterize the identified nerves of the brachial plexus using a bipolar electrocautery set at 15, and confirm successful injury by observing upper extremity muscle twitches.</li>
	<li>Place a small piece of an absorbable gelatin sponge (approximately 2 mm by 2 mm), between the proximal and distal segments of the brachial plexus to prevent nerve regeneration (Figure 2B).</li>
	<li>Close the skin using a 7-0 absorbable suture in a continuous suture pattern and apply a veterinary tissue adhesive to prevent wound dehiscence (Figure 3).</li>
</ol>
5. Postoperative management
<ol>
	<li>Place the rat pup on a heating pad with nesting material from the rat dam&#39;s cage (Figure 4). Monitor the respiratory rate and movements of the rat pup until it returns to normal respiratory patterns.</li>
	<li>To prevent maternal rejection, rub the rat pup gently with the home-cage nesting material before placing it back with the dam.</li>
	<li>Inspect rat pup 3 times&#160;a day for the first 48 h post surgery. If signs of pain or absence of a milk spot are observed, administer supplemental analgesia (buprenorphine&#160;0.05 mg/kg s.c.).</li>
	<li>Closely monitor for postoperative complications, including wound dehiscence, wound infection, reduced limb sensation with potential automutilation, and maternal cannibalism.</li>
	<li>Weigh the rat pup daily. If the rat pup exhibits weight loss or no weight gain for 2 consecutive days, consider it a failure to thrive and proceed with euthanasia by an injection of pentobarbital (390 mg/mL) intraperitoneal.</li>
	<li>Assess motor function 1 day post surgery and follow up motor function weekly using a limb movement scale: 0 = absent function, 1 = partial function, 2 = normal symmetric function.</li>
</ol>

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<li>Abzug, J. M., Mehlman, C. T., Ying, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Assessment+of+current+epidemiology+and+risk+factors+surrounding+brachial+plexus+birth+palsy%5BTitle%5D)+AND+%22J+Hand+Surg+Am%22%5BJournal%5D)">Assessment of current epidemiology and risk factors surrounding brachial plexus birth palsy.</a> J Hand Surg Am. 44 (6), e1-e515 (2019).</li>
<li>Foad, S. L., Mehlman, C. T., Ying, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((The+epidemiology+of+neonatal+brachial+plexus+palsy+in+the+United+States%5BTitle%5D)+AND+%22J+Bone+Joint+Surg+Am%22%5BJournal%5D)">The epidemiology of neonatal brachial plexus palsy in the United States.</a> J Bone Joint Surg Am. 90 (6), 1258-1264 (2008).</li>
<li>Walsh, J. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Neonatal+brachial+plexus+injury%3A+Comparison+of+incidence+and+antecedents+between+2+decades%5BTitle%5D)+AND+%22Am+J+Obstet+Gynecol%22%5BJournal%5D)">Neonatal brachial plexus injury: Comparison of incidence and antecedents between 2 decades.</a> Am J Obstet Gynecol. 204 (4), e1-e324 (2011).</li>
<li>Pondaag, W., Malessy, M. J., van Dijk, J. G., Thomeer, R. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Natural+history+of+obstetric+brachial+plexus+palsy%3A+A+systematic+review%5BTitle%5D)+AND+%22Dev+Med+Child+Neurol%22%5BJournal%5D)">Natural history of obstetric brachial plexus palsy: A systematic review.</a> Dev Med Child Neurol. 46 (2), 138-144 (2004).</li>
<li>Foad, S. L., Mehlman, C. T., Foad, M. B., Lippert, W. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Prognosis+following+neonatal+brachial+plexus+palsy%3A+An+evidence-based+review%5BTitle%5D)+AND+%22J+Child+Orthop%22%5BJournal%5D)">Prognosis following neonatal brachial plexus palsy: An evidence-based review.</a> J Child Orthop. 3 (6), 459-463 (2009).</li>
<li>Hoeksma, A. F., ter Steeg, A. M., Nelissen, R. G., van Ouwerkerk, W. J., Lankhorst, G. J., de Jong, B. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Neurological+recovery+in+obstetric+brachial+plexus+injuries%3A+An+historical+cohort+study%5BTitle%5D)+AND+%22Dev+Med+Child+Neurol%22%5BJournal%5D)">Neurological recovery in obstetric brachial plexus injuries: An historical cohort study.</a> Dev Med Child Neurol. 46 (2), 76-83 (2004).</li>
<li>Pondaag, W., Malessy, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((The+evidence+for+nerve+repair+in+obstetric+brachial+plexus+palsy+revisited%5BTitle%5D)+AND+%22Biomed+Res+Int%22%5BJournal%5D)">The evidence for nerve repair in obstetric brachial plexus palsy revisited.</a> Biomed Res Int. 2014, 434619(2014).</li>
<li>Executive SHORT ABSTRACT: Neonatal brachial plexus palsy. Report of the American College of Obstetricians and Gynecologists Task Force on Neonatal Brachial Plexus Palsy. Obstet Gynecol. 123 (4), 902-904 (2014).</li>
<li>Zlotolow, D. A., Chen, C. J., Crowe, C. S., Park, E., Kozin, S. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((A+novel+intraoperative+classification+for+brachial+plexus+birth+injury+based+on+operative+findings+in+162+patients%5BTitle%5D)+AND+%22J+Hand+Surg+Eur+Vol%22%5BJournal%5D)">A novel intraoperative classification for brachial plexus birth injury based on operative findings in 162 patients.</a> J Hand Surg Eur Vol. , (2025).</li>
<li>Smith, B. W., Daunter, A. K., Yang, L. J., Wilson, T. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((An+update+on+the+management+of+neonatal+brachial+plexus+palsy-Replacing+old+paradigms%3A+A+review%5BTitle%5D)+AND+%22JAMA+Pediatr%22%5BJournal%5D)">An update on the management of neonatal brachial plexus palsy-Replacing old paradigms: A review.</a> JAMA Pediatr. 172 (6), 585-591 (2018).</li>
<li>Bauer, A. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Microsurgery+for+brachial+plexus+injury+before+versus+after+6+months+of+age%3A+Results+of+the+multicenter+treatment+and+outcomes+of+brachial+plexus+injury+%28TOBI%29+study%5BTitle%5D)+AND+%22J+Bone+Joint+Surg+Am%22%5BJournal%5D)">Microsurgery for brachial plexus injury before versus after 6 months of age: Results of the multicenter treatment and outcomes of brachial plexus injury (TOBI) study.</a> J Bone Joint Surg Am. 102 (3), 194-204 (2020).</li>
<li>Muhlestein, W. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Impact+of+timing+of+primary+nerve+surgery+on+shoulder%2C+forearm%2C+and+elbow+recovery+in+neonatal+brachial+plexus+palsy%5BTitle%5D)+AND+%22Neurosurgery%22%5BJournal%5D)">Impact of timing of primary nerve surgery on shoulder, forearm, and elbow recovery in neonatal brachial plexus palsy.</a> Neurosurgery. , (2023).</li>
<li>Hulleberg, G., Elvrum, A. K., Brandal, M., Vik, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Outcome+in+adolescence+of+brachial+plexus+birth+palsy%3A+69+individuals+re-examined+after+10-20+years%5BTitle%5D)+AND+%22Acta+Orthop%22%5BJournal%5D)">Outcome in adolescence of brachial plexus birth palsy: 69 individuals re-examined after 10-20 years.</a> Acta Orthop. 85 (6), 633-640 (2014).</li>
<li>Sarac, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((What+range+of+motion+is+achieved+5+years+after+external+rotationplasty+of+the+shoulder+in+infants+with+an+obstetric+brachial+plexus+injury%5BTitle%5D)+AND+%22Clin+Orthop+Relat+Res%22%5BJournal%5D)">What range of motion is achieved 5 years after external rotationplasty of the shoulder in infants with an obstetric brachial plexus injury.</a> Clin Orthop Relat Res. 478 (1), 114-123 (2020).</li>
<li>Adidharma, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Shoulder+release+and+tendon+transfer+following+neonatal+brachial+plexus+palsy%3A+Gains%2C+losses%2C+and+midline+function%5BTitle%5D)+AND+%22Plast+Reconstr+Surg%22%5BJournal%5D)">Shoulder release and tendon transfer following neonatal brachial plexus palsy: Gains, losses, and midline function.</a> Plast Reconstr Surg. 146 (2), 321-331 (2020).</li>
<li>Ruoff, J. M., van der Sluijs, J. A., van Ouwerkerk, W. J., Jaspers, R. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Musculoskeletal+growth+in+the+upper+arm+in+infants+after+obstetric+brachial+plexus+lesions+and+its+relation+with+residual+muscle+function%5BTitle%5D)+AND+%22Dev+Med+Child+Neurol%22%5BJournal%5D)">Musculoskeletal growth in the upper arm in infants after obstetric brachial plexus lesions and its relation with residual muscle function.</a> Dev Med Child Neurol. 54 (11), 1050-1056 (2012).</li>
<li>Gosk, J., Wnukiewicz, W., Urban, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((The+effect+of+perinatal+brachial+plexus+lesion+on+upper+limb+development%5BTitle%5D)+AND+%22BMC+Musculoskelet+Disord%22%5BJournal%5D)">The effect of perinatal brachial plexus lesion on upper limb development.</a> BMC Musculoskelet Disord. 15, 116(2014).</li>
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</ol>

The authors have no conflicts of interest to declare.

This protocol details the development of a brachial plexus injury in a neonatal rat to conduct research on the short-term and long-term outcomes of BPBI, explore treatment options and understand sequela.
The use of a noninvasive rodent model to study brachial plexus injury has been previously described; however, these models have not been specifically adapted to replicate a specific type of nerve injury21,22. By focusing on postnatal d...

Brachial plexus birth injury (BPBI) is a traumatic nerve injury that occurs during delivery. Traction forces during a complicated delivery, often due to shoulder dystocia, prolonged labor, or fetal macrosomia, result in weakness or paralysis in the affected arm1. The incidence ranges from 1-2 per 1,000 live births2,3,4. While most babies recover full function, 30% have residual symptoms as they grow into adulthood, such as functional limitations, limb length inequalities, deformities, and joint contractures5,6,7,8.
The BPBI model demonstrates different injury patterns with implications for treatment and prognosis. Upper plexus injuries (C5-C6, Erb palsy) are the most common and predominantly involve rupture rather than avulsions9. In contrast, pan-plexal injuries (C5-T1) frequently demonstrate a mixed pattern of cranial root ruptures and caudal avulsions10. Avulsions are preganglionic injuries that disrupt the dorsal root ganglion with no capacity for spontaneous recovery11.
Current clinical management strategies range from conservative physical therapy to early microsurgical nerve reconstruction, depending on the severity of the injury12,13. Patients often need secondary surgeries, including soft-tissue releases, tendon transfers, and osteotomies, to further improve motor function, quality of life, and secondary musculoskeletal sequelae. However, the effectiveness of these early and late interventions varies14,15,16. Moreover, the altered musculoskeletal development contributes to functional limitations, limb length inequalities, and other deformities, not currently amenable to treatment, highlighting the need for further research17,18. Therefore, there remains a critical need for a reliable, feasible, and reproducible animal model to investigate these injuries.
Rodent models are commonly used in brachial plexus injury models, with mice the most common choice due to their cost-effectiveness and ease of handling. However, creating a reproducible neonatal brachial plexus injury can be anatomically challenging due to their small size. Large animal models such as rabbits, pigs, and primates offer several advantages for model creation, but at a significantly higher cost19. Rats, on the other hand, are larger and more genetically similar to humans than mice, while remaining substantially more cost-effective and accessible than larger animal models. Therefore, there remains a need for a feasible and reproducible animal to investigate BPBI. This study describes a step-by-step pan-plexal BPBI creation model in neonatal rats that can be used to study injury mechanisms, treatment interventions, and short- and long-term sequelae.

<table><tbody><tr><td>1 mL Syringe Luer-Lok Tip&amp;nbsp;</td><td>BD&amp;nbsp;</td><td>309628</td><td></td></tr><tr><td>7-0 Coated Vicryl (Polyglactin 910)</td><td>Ethicon</td><td>J576G</td><td></td></tr><tr><td>70% isopropylalcohol</td><td>Vet-One</td><td>13985-598-01</td><td></td></tr><tr><td>Absorable gelatin sponge&amp;nbsp;</td><td>Surgifoam&amp;nbsp;</td><td>ETH1972</td><td></td></tr><tr><td>Betadine Solution 5% Povidone-Iodine Antiseptic Microbicide&amp;nbsp;</td><td>PBS Animal Health&amp;nbsp;</td><td>11205</td><td></td></tr><tr><td>Nesting material&amp;nbsp;</td><td>Bed &#039;r Nest</td><td>BRN8SR</td><td></td></tr><tr><td>Bipolar Cords</td><td>ASSI&amp;nbsp;</td><td>ASSI.ATK26426</td><td></td></tr><tr><td>Buprenorphine (Base 0.5 mg/mL) Extended Release&amp;nbsp;</td><td>Wedgewood connect</td><td>49426-0517-1</td><td></td></tr><tr><td>Cage enrichments</td><td>Twist &#039;n Rich</td><td>10003949</td><td></td></tr><tr><td>Cellulose based bedding&amp;nbsp;</td><td>Alpha Dri</td><td>NC2193839</td><td></td></tr><tr><td>Expanded polystyrene (Styrofoam)</td><td>Fisher&amp;nbsp;</td><td>22-130-407</td><td></td></tr><tr><td>FREER skin hook</td><td>Freer</td><td>MI2152</td><td></td></tr><tr><td>Gillies Skin Hook Semi-sharp</td><td>DTR</td><td>GHB2001</td><td></td></tr><tr><td>Isoflurane Auto-Flow Anesthesia Machine</td><td>E-Z Systems&amp;nbsp;</td><td>EZ-190F</td><td></td></tr><tr><td>Isoflurane, USP&amp;nbsp;</td><td>Patterson Veterinary&amp;nbsp;</td><td>1403-704-06</td><td></td></tr><tr><td>Jewelers Bipolar Forceps Non-Stick, 11 cm, straight pointed tip, 0.25 mm, tip diameter</td><td>ASSI&amp;nbsp;</td><td>ASSI.BPNS11223</td><td></td></tr><tr><td>Micro Scissors Bayonet Style</td><td>ASSI&amp;nbsp;</td><td>ASSI.SNS21</td><td></td></tr><tr><td>Microscope (surgical)&amp;nbsp;</td><td>Leica&amp;nbsp;</td><td>M525 F40</td><td></td></tr><tr><td>Microsurgical Dumont #4 forceps Dumont Swiss made 1708-4TM-PO</td><td>Ambler Surgical&amp;nbsp;</td><td>31-906</td><td></td></tr><tr><td>Microsurgical needle holder&amp;nbsp;</td><td>ASSI&amp;nbsp;</td><td>B-14-8</td><td></td></tr><tr><td>Nose Cone, 9mm, Mouse, length 2cm</td><td>VetEquip</td><td>921609</td><td></td></tr><tr><td>Pentobarbital-euthanasia vial (390 mg/mL) 250 mL</td><td>Fatal plus</td><td>9373</td><td></td></tr><tr><td>Plastic food wrap foil</td><td>Press &#039;n Seal&amp;nbsp;</td><td>Press&#039;n-70-1-no3</td><td></td></tr><tr><td>Single-use Needles, 30 G</td><td>BD&amp;nbsp;</td><td>14-821-13A</td><td></td></tr><tr><td>Small Animal Heated Operating table (adjustable)</td><td>Peco Services Ltd&amp;nbsp;</td><td>69023</td><td></td></tr><tr><td>Stainless Steel Blade No. 11&amp;nbsp;</td><td>Bard Parker</td><td>371211</td><td></td></tr><tr><td>Sterile towel drape&amp;nbsp;</td><td>Dynarex Corporation&amp;nbsp;</td><td>4410</td><td></td></tr><tr><td>Tissue adhesive</td><td>Vetbond 3M</td><td>NC9259532</td><td></td></tr><tr><td>Wood Handled Cotton Swabs and Applicators</td><td>Fisher&amp;nbsp;</td><td>22-363-157</td><td></td></tr></tbody></table>

development of a neonatal rat model for brachial plexus birth injury

Development of a Neonatal Rat Model for Brachial Plexus Birth Injury

Studying brachial plexus birth injuries (BPBI) has been challenging due to heterogeneous clinical presentations and limited reliable animal models. To that end, we have developed a surgical protocol that reproducibly induces a pan-plexal neonatal brachial plexus injury in 5-day-old Sprague-Dawley rat pups. In this article, step-by-step instructions are provided for approaching the brachial plexus in a rat pup. The technique was performed on 15 Sprague Dawley rat pups. Using a dorsal approach under operative microscopy, a 5 mm dorsal incision was made starting at the base of the skull towards the level of C7-T1 vertebral transition. Blunt dissection is carried down to the trapezius muscle, followed by dissection through the underlying rhomboid and levator scapulae muscles. After identifying anatomical landmarks such as the spine and the scapula, the superior angle of the scapula was gently retracted to visualize the brachial plexus. The brachial plexus was localized and cauterized, evidenced by observable twitches in the upper extremity. To prevent nerve regeneration, a small block of an absorbable gelatin sponge was placed between the proximal and distal ends of the injured nerves. This procedure was successfully performed on all 15 rat pups with 87% survival. Postoperative and at sacrifice, all surviving rats demonstrated complete pan-plexal injuries, validating this model as effective and reproducible for research in brachial plexus birth injuries.

The effectiveness of the surgical technique can be evaluated by the absence of movement in the affected limb, the presence of contractures, reduced range of motion, and, upon sacrifice, the degree of muscle atrophy, limb shortening, and morphological bone and muscle differences compared to the unaffected limb. A total of 15 rat pups were included in this study. During the survival period, two of the rat pups failed to thrive postoperatively due to poor weight gain. Self-mutilation was observed in 2 out of the 13 survivin...

This protocol presents a step-by-step instruction to create a neonatal brachial plexus injury in rats to be used as a model in brachial plexus birth injury research.

Studying brachial plexus birth injuries (BPBI) has been challenging due to heterogeneous clinical presentations and limited reliable animal models. To ...

This protocol describes the development of a neonatal rat model for brachial plexus birth injury. Brachial plexus birth injury is a nerve injury that occurs during a difficult delivery. While many infants recover spontaneously, up to 30%developed long-term sequelae.Current treatments range from physical therapy to microsurgical nerve repair, but outcomes remain viable. A reliable animal model is therefore needed to study the underlying mechanisms and long-term consequences of brachial plexus birth injury. All animal procedures were performed with approval of the Institutional Animal Care and Use Committee.A multiparous pregnant Sprague Dawley rat at gestational day 14 is housed under standard laboratory conditions. During late gestation, a researcher visited the dam daily and performed olfactory conditioning by placing cotton swabs with ethanol and Betadine in the cage. Additional bedding material was provided to allow the dam to create a bigger nest.All surgical instruments were sterilized by autoclaving. A surgical bed was prepared from polystyrene. Surgeries are performed on five day old rat pups.Anesthesia is induced by 2%isoflurane in oxygen, and confirmed by the absence of a toe-pinch reflex. The rat pup is placed on a pre-warmed heating pad. Each pup is marked with a unique number.Extended release buprenorphine is administered for analgesia and anesthesia is maintained at 1.5 to 2%isoflurane. throughout the procedure. The surgical field is disinfected with alternating scrubs of Betadine and ethanol before the pup is positioned in the polystyrene mold.The head is secured to the nose cone with tape, and the lower body is stabilized using wrap to minimize movement. Create a midline cervical incision for approximately five millimeters in length, extending from the base of the skull towards the C 71 level. Create the incision using a number 11 blade.Superficial vessels are cauterized. Dissect through the trapezius and the underlying rhomboid and levator scapulae muscles using cauterization. Be careful to not cauterize the skin edges to avoid thermal injury.Identify and isolate the brachial plexus via blunt dissection. Cauterize the identified nerve of the brachial plexus. Confirm a successful injury by observing upper extremity muscle twitches.Place an absorbable gelatin sponge between the proximal and distal segments of the brachial plexus to prevent nerve regeneration. Close the skin using 4-0, 7-0 suture in a continuous pattern. Apply a tissue adhesive to prevent wound dehiscence.Place the rat pup on a heating pad with nesting material from the rat dam's cage. Monitor the respiratory rate and movements of the rat pup until it returns to normal respiratory patterns. To prevent maternal rejection, rub the rat pup gently with the home cage nesting material before placing it back to the dam.Postoperatively, the effectiveness of the surgical technique can be evaluated by the absence of movement in the effectively limb. Motor function was assessed daily during the first two weeks postoperatively and weekly thereafter. Briefly, absence of limb movement was scored as zero, partial limb movement was scored as one, and normal symmetric movement was graded as two.All included rat pups exhibited a pan-plexal injury and scored zero on the movement scale. Upon sacrifice, the degree of muscle atrophy, limb shortening, and the presence of contractors can be evaluated. To conclude this protocol provides a reproducible neonatal rat model to investigate brachial plexus birth injury.

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Research

JoVE Journal

Neuroscience

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Learn to develop a reproducible neonatal rat model for studying brachial plexus birth injury using Sprague Dawley pups. This protocol enables investigation of injury mechanisms and therapeutic interventions.

Development of a Neonatal Rat Model for Brachial Plexus Birth Injury

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