IGF-1 induces neonatal climbing-fibre plasticity in the mature rat cerebellum
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Updated: Aug 30, 2026
Utilizing In Vivo Postnatal Electroporation to Study Cerebellar Granule Neuron Morphology and Synapse Development
Published on: June 9, 2021
Rachel M Sherrard1, Adrian J Bower
1Developmental Neuroplasticity Laboratory, Department of Anatomy, School of Biomedical Science, James Cook University, Queensland 4811, Australia. Rachel.Sherrard@jcu.edu.au
Insights
Insulin-like growth factor 1 (IGF-1) promotes neuroplasticity in mature rats, enabling reinnervation of the cerebellum after injury. This growth factor treatment extends the window for nerve regeneration in a myelinated environment.
Area of Science:
- Neuroscience
- Developmental Biology
- Regenerative Medicine
Background:
- Neonatal rat olivocerebellar pathway injury triggers compensatory reinnervation.
- This neuroplasticity has a critical period, typically closing between postnatal days 7-10.
- Growth factors can extend this critical period, but efficacy in mature, myelinated environments is unknown.
Purpose of the Study:
- To investigate if insulin-like growth factor 1 (IGF-1) can promote transcommissural reinnervation in a mature, myelinated rat cerebellum.
- To determine if IGF-1 can extend developmental neuroplasticity beyond the critical period.
Main Methods:
- Unilateral pedunculotomy was performed on rats aged 11-30 days.
- Insulin-like growth factor 1 (IGF-1) was injected into the denervated cerebellum 24 hours post-surgery.
- Transcommissural reinnervation and its topographical organization were analyzed.
Main Results:
- IGF-1 induced transcommissural olivocerebellar reinnervation in all treated animals.
- Reinnervation displayed organization consistent with normal olivocerebellar topography.
- This occurred even when pedunculotomy was performed up to postnatal day 20.
Conclusions:
- IGF-1 can effectively promote developmental neuroplasticity in a mature, myelinated environment.
- IGF-1 facilitates appropriate target reinnervation following cerebellar injury in older rats.
- This finding has implications for therapeutic strategies targeting nerve regeneration.
Abstract:
Following unilateral transection (pedunculotomy) of the neonatal rat olivocerebellar pathway, the remaining inferior olive reinnervates the denervated hemicerebellum with correct topography. The critical period for this transcommissural reinnervation closes between postnatal days 7 and 10 but can be extended by injection of growth factors. Whether growth factor treatment can extend developmental plasticity into a mature, myelinated milieu remains unknown. Rats aged 11-30 days, underwent unilateral pedunculotomy followed 24 h later by injection of insulin-like growth factor 1 (IGF-1) into the denervated cerebellum. In all animals, IGF-1 induced transcommissural olivocerebellar reinnervation, which displayed organisation consistent with normal olivocerebellar topography even following pedunculotomy up to day 20. Thus IGF-1 can reproduce developmental neuroplasticity to promote appropriate target reinnervation in a mature myelinated environment.
