February 9th, 2024
Here, we present a concise protocol for creating a preterm rat model, facilitating research on early postnatal pain management. The method involves performing a cesarean section three days before the expected birth, extracting preterm rat pups via hysterectomy, and integrating them with the biological offspring of a surrogate dam.
To begin, obtain a partially anesthetized pre-term pregnant dam. After euthanizing, make a three centimeter cut in the midline of the lower abdomen, followed by a two centimeter longitudinal cut. Then, make an incision along the antimesenteric border in the midline portion of each uterine tube from these cuts.
Then perform a hysterectomy and gently extract the rat pups and placenta one by one. Bathe the pup to prevent cannibalism by surrogate dams. After drying the pup, remove any traces of blood.
Using paper towels, clear the airways of the pup thoroughly. Next, cut the umbilical cord just below the placenta, and using cotton soaked in hydrogen peroxide, stop the bleeding from the cord area. Place the pup in a Petri dish under heated infrared lighting at 28 degrees Celsius until breathing regularizes.
For the adoption procedure, house each foster mother with the litter separately, and maintain the integrity of the cages. Mark each term puppy from the foster hand. Then, place the pre-term pup along with the foster mother's own pups outside the nest for familiarization with the new pups'scent.
Remove the foster mother's pups from the nest and mix the adoptive offspring with the biological offspring. Confirm effective adoption when the surrogate mother collects both her own and the pre-term pups into her nest.
This study presents a protocol for establishing a preterm rat model to aid in research focused on early postnatal pain management. The method includes a cesarean section performed three days before expected birth to extract preterm rat pups and facilitate their adoption by a surrogate dam's biological offspring.