Auditory brainstem and middle latency responses in non-human primates.
Auditory brainstem (ABR) and middle latency responses (MLR) were obtained from each ear in 8 crab-eating macaques, 4 white-handed gibbons, 4 siamangs and 2 orangutans. Macaques ranged in age from 5 days to 15 years with the 6 older animals in age-matched, male-female pairs. From each animal, latency-intensity functions were obtained and multiple MLR recordings were measured at 60 and 70 dB. Latency-intensity functions, interwave intervals, thresholds and percent detectability were calculated for ABR waveforms. Waves II and IV were largest in amplitude and were most consistently detected at low stimulus intensities in all species tested. Waves I and II had adult latencies in the youngest animal tested (5-day-old macaque), while waves III and IV were prolonged in comparison to the 15-month-old macaque, in whom latencies had reached adult values. There were no apparent sex differences in evoked potentials in the age-matched, male-female pairs. A broad, negative MLR at 7-13 ms was observed in all animals. Longer latency MLRs varied among animals of the same species, but were replicable in some individuals, including the youngest macaque (5 days) and orangutan (7 months). These data were compared to responses obtained in humans, other primates and other vertebrates.
D000818:Animals; D001306:Auditory Pathways / Q000502:physiology*; D001309:Auditory Threshold; D001933:Brain Stem / Q000502:physiology*; D005072:Evoked Potentials, Auditory; D005260:Female; D006922:Hylobates; D008252:Macaca fascicularis; D008297:Male; D009431:Neural Conduction; D011148:Pongo pygmaeus; D011930:Reaction Time / Q000502:physiology; D013045:Species Specificity