Functional changes of the peripheral nervous system with aging in the mouse

• Published in: Neurobiology of aging Vol. 17; no. 1; pp. 73 - 77
• Main Authors: Verdú, Enrique, Butí, Miquel, Navarro, Xavier
• Format: Journal Article
• Language: English
• Published: London Elsevier Inc 1996; Elsevier Science
• Subjects: Aging; Aging - physiology; Animals; Biological and medical sciences; Electric Stimulation; Electrophysiology; Female; Fundamental and applied biological sciences. Psychology; Mice; Mice, Inbred Strains; Motor axons; Nociceptive axons; Peripheral nerve; Peripheral Nervous System - physiology; Peripheral nervous system. Autonomic nervous system. Neuromuscular transmission. Ganglionic transmission. Electric organ; Reaction Time - physiology; Sciatic Nerve - physiology; Sudomotor axons; Vertebrates: nervous system and sense organs; Aging; Electrophysiology; Peripheral nerve; Motor axons; Nociceptive axons; Sudomotor axons; Peripheral nervous system; Vertebrata; Senescence; Mammalia; Mouse; Rodentia; Age; Sciatic nerve
• ISSN: 0197-4580; 1558-1497
• DOI: 10.1016/0197-4580(95)02010-1

The influence of aging on peripheral nerve and target organ function was investigated in six groups of mice aged 2, 6, 9, 12, 18, and 24 months. Sudomotor, motor, and sensory functions mediated by the sciatic nerve were evaluated by silicone imprints, electrophysiological recordings and pinprick test from the distal hindpaw. Nerve conduction was also studied in the caudal nerves. The results showed that the number of sweat glands reactive to pilocarpine does not change significantly with aging, but the size of the sweat droplets is smaller in aged mice than in young mice. The amplitude of muscle and nerve action potentials evoked by stimulation of sciatic and caudal nerves decreased progressively from 2 to 24 months, while the latencies decreased from 2 to 6 months, remained unchanged until 12 months and increased thereafter. All the animals of the six groups studied showed positive, indistinguishable responses to pinprick. These results indicate that neurophysiological responses mediated by large diameter nerve fibers deteriorated with age, while those dependent of small fibers were preserved.