Impairment of peripheral sensory innervation in senescence.

Sensorimotor disturbances are common among elderly and one of the main factors depreciating life quality in senescence. Mechanistically sensory deficits during aging include not only degenerative and regressive events but also phenotypic switches among sensory neurons as well as remodeling of sensory innervation. The pattern of changes suggests that an underlying mechanism is a sustained dependence of sensory neurons on target tissues, and that this dependence, at least in part, appears to be mediated through signaling by target-derived trophic factors.

Postnatal changes in the termination pattern of recurrent axon collaterals of triceps surae alpha-motoneurons in the cat.

alpha-Motoneurons innervating the triceps surae and short plantar muscles were stained intracellularly with horseradish peroxidase (HRP) in 0-44-day-old kittens and adult cats. The terminal arborizations of the recurrent axon collaterals in the spinal cord were studied in the light microscope (LM). The short plantar motoneurons lacked axon collaterals in all age groups.