Intraspinal non-neuronal cellular responses to peripheral nerve injury

Area of Science:

• Neuroscience
• Cell Biology

Background:

• Reactive cells accumulate around motor neurons after axotomy.
• Previous studies noted these cells mainly in ventral gray matter.
• A recent study reported reactive cells in dorsal gray matter following sciatic axotomy in immature rats.

Purpose of the Study:

• To investigate if reactive cell presence in dorsal gray matter is age-dependent.
• To determine the origin of reactive cells in dorsal gray matter.

Main Methods:

• Sciatic nerve axotomy in rats of varying ages (17 days to 16 months).
• Transection and crushing of various peripheral nerves (tibial, medial gastrocnemius, sciatic, sural).
• Light microscopic evaluation of spinal cord tissue post-operatively.

Main Results:

• Reactive cells consistently appeared in both dorsal and ventral gray matter, irrespective of age.
• Transection of sensory (sural) nerves induced reactive cells in dorsal gray matter but not ventral.
• Transection of motor nerves induced cells in both dorsal and ventral gray matter.

Conclusions:

• The presence of reactive cells in dorsal gray matter is not solely due to immaturity.
• Reactive cells in dorsal gray matter are associated with central processes of dorsal root ganglion cells.