Using manganese-enhanced MRI to assess optic nerve regeneration

Area of Science:

• Neuroscience
• Regenerative Medicine
• Medical Imaging

Background:

• Optic nerve (ON) crush or transection injuries lead to significant retinal ganglion cell (RGC) death and loss of neural connections.
• While RGC axon regeneration is typically inhibited in the central nervous system (CNS), rodent models show promise for regeneration after therapeutic intervention.
• Traditional assessment methods for ON regeneration require animal sacrifice, preventing longitudinal studies.

Purpose of the Study:

• To introduce Manganese-enhanced MRI (MEMRI) as a technique for in vivo monitoring of optic nerve regeneration.
• To provide a protocol for ON lesioning and MEMRI application in rodents.
• To enable serial assessment of axonal regeneration and neuronal connectivity after therapeutic interventions.

Main Methods:

• Utilizing the paramagnetic properties of manganese ions (Mn(2+)) for neuronal uptake and transport.
• Applying MEMRI for serial in vivo monitoring of entire axonal projections.
• Implementing a generic protocol for ON lesioning and subsequent MEMRI analysis in rodent models.

Main Results:

• MEMRI allows for non-invasive, longitudinal tracking of axonal regeneration in the optic nerve.
• The technique enables assessment of neuronal connectivity and regenerative responses to treatments.
• This method overcomes limitations of traditional histological assessments by avoiding animal sacrifice.

Conclusions:

• MEMRI is a suitable technique for evaluating optic nerve regeneration in vivo.
• This approach facilitates the study of therapeutic interventions for ON injuries.
• The protocol supports longitudinal monitoring of RGC axon regeneration and neuronal recovery.