Somatosensory evoked potentials of median and tibial nerves in rhesus monkeys (Macaca mulatta) under captivity: influence of ontogenic status in neonatal, infant, young, adult, and senile stages.

ABSTRACT

BACKGROUND: Somatosensory evoked potentials (SEPs) constitute a useful neurophysiologic tool commonly used to assess the functionality and developmental degree of the nervous system. OBJECTIVE: To analyze somatosensory pathways of the Macaca mulatta species throughout different ontogenetic statuses. METHODS: Twenty non-human primates were divided into five age-dependant groups. Recording of SEPs was executed by stimulation of lower limb at the tibial nerve and upper limb and recorded at the median nerve. RESULTS: Two wave series were observed for all groups for both limbs studied. Significant differences were found at the upper right limb at C4, C7 and also for the antecubital fossa site. The lower limbs showed a single significant right-wing deflection. CONCLUSIONS: Differences found in signals generated by the nervous system in response to somatosensory stimuli among the studied groups are thought to be developmental in origin, as the most remarkable deviations were seen in younger monkeys.