Author/Editor     Kovačič, Uroš; Sketelj, Janez; Bajrović, Fajko F
Title     Age-related differences in the reinnervation after peripheral nerve injury
Type     članek
Source     In: Geuna S, Tos P, Battiston B, editors. Essays on peripheral nerve repair and regeneration. International review of neurobiology; vol 87. Amsterdam: Academic Press,
Vol. and No.     Letnik 87
Publication year     2009
Volume     str. 465-82
Language     eng
Abstract     Numerous and extensive functional, structural, and biochemical changes characterize intact aged peripheral nervous system. Functional recovery after peripheral nerve injury depends on survival of injured neurons and functional reinnervation of target tissue by regeneration of injured axons and collateral sprouting of uninjured (intact) adjacent axons. The rate of axonal regeneration becomes slower and its extent (density and number of regenerating axons) decreases in aged animals. Aging also impairs terminal sprouting of regenerated axons and collateral sprouting of intact adjacent axons, thus further limiting target reinnervation and its functional recovery. Decreased survival of aged noninjured and injured neurons, limited intrinsic growth potential of neuron, alteration in its responsiveness to stimulatory or inhibitory environmental factors, and changes in the peripheral neural pathways and target tissues are possible reasons for impaired reinnervation after peripheral nerve injury in old age. The review of present data suggests that this impairment is mostly due to the age-related changes in the peripheral neural pathways and target tissues, and not due to the limited intrinsic growth capacity of neurons or their reduced responsiveness to trophic factors. Age-related alterations in the soluble target derived neurotrophic factors, like nerve growth factor, and nonsoluble extracellular matrix components of neural pathways, like laminin, might be important in this respect.
Descriptors     AGING
ANIMALS
AXONS
CELL SURVIVAL
NERVE GROWTH FACTORS
NERVE REGENERATION
NEURONS
PERIPHERAL NERVES
SIGNAL TRANSDUCTION