Related Experiment Video
Updated: Jun 2, 2026
Enhancing the Development and Growth of Infant Cerebral Palsy Rats Using Selective Spinal Manipulations
Published on: February 2, 2024
Spinal anesthesia in infant rats: development of a model and assessment of neurologic outcomes
Barak Yahalom1, Umeshkumar Athiraman, Sulpicio G Soriano
1Department of Anesthesiology, Perioperative and Pain Medicine, Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts, USA.
Insights
This study found that spinal anesthesia in infant rats did not cause neurodevelopmental toxicity. Infant spinal anesthesia appears safe, with no long-term motor skill impairments observed.
Area of Science:
- Anesthesiology
- Neuroscience
- Pediatric Surgery
Background:
- General anesthesia in infants raises concerns for neurodevelopmental toxicity.
- Spinal anesthesia offers an alternative for specific infant surgical procedures.
- A rat model was developed to assess spinal anesthesia's safety in neonates.
Purpose of the Study:
- To evaluate the potential neurodevelopmental toxicity of spinal anesthesia in infant rats.
- To compare spinal anesthesia with general anesthesia in a preclinical model.
- To assess the long-term effects of infant anesthesia on neurodevelopment and motor function.
Main Methods:
- Infant rats (postnatal days 7, 14, 21) received no treatment, isoflurane (general anesthesia), or spinal bupivacaine.
- Neurobehavioral tests, blood gas analysis, and apoptosis staining (cleaved caspase-3) were performed.
- Adult motor performance was assessed using Rotarod testing.
Main Results:
- Spinal anesthesia with bupivacaine was effective and transient in all infant rat age groups.
- No significant increase in brain or spinal cord apoptosis was observed with spinal anesthesia.
- General anesthesia (6h isoflurane) exposure led to increased apoptosis; however, all groups exhibited normal adult motor function.
Conclusions:
- Spinal anesthesia is a feasible and safe anesthetic technique in infant rats.
- This method appears to be benign, showing no neuroapoptotic or neuromotor deficits.
- Findings support spinal anesthesia as a potentially safer alternative to general anesthesia in neonates.
Background:
Previous studies in infant rats and case-control studies of human infants undergoing surgery have raised concerns about potential neurodevelopmental toxicities of general anesthesia. Spinal anesthesia is an alternative to general anesthesia for some infant surgeries. To test for potential toxicity, a spinal anesthesia model in infant rats was developed.
Methods:
Rats of postnatal ages 7, 14, and 21 days were assigned to no treatment, 1% isoflurane for either 1 h or 6 h, or lumbar spinal injection of saline or bupivacaine at doses of 3.75 mg/kg (low dose) or 7.5 mg/kg (high dose). Subgroups of animals underwent neurobehavioral testing and blood gas analysis. Brain and lumbar spinal cord sections were examined for apoptosis using cleaved caspase-3 immunostaining. The lumbar spinal cord was examined histologically.Rats exposed to spinal or general anesthesia as infants underwent Rotarod testing of motor performance as adults. Data were analyzed using ANOVA with general linear models, Friedman tests, and Mann-Whitney U tests, as appropriate.
Results:
Bupivacaine 3.75 mg/kg was effective for spinal anesthesia in all age groups. Impairments in sensory and motor function recovered in 40-60 min. Blood gases were similar among groups. Brain and spinal cord apoptosis increased in rats receiving 6 h of 1% isoflurane, but not among the other treatments. All groups showed intact motor performance at adulthood.
Conclusions:
Spinal anesthesia is technically feasible in infant rats and appears benign in terms of neuroapoptotic and neuromotor sequelae.
