Recording somatosensory evoked potentials by biotelemetry in common marmosets (callithrix jacchus), a pilot study

Abstract

Veterinary medicine has a lack of knowledge about objectively measuring pain and the efficacy of analgesics in non-human primates (NHP). Upcoming use of biotelemetry in animal research seems an improvement for studying nociception in animals. Biotelemetry has never been used for objective pain measuring in NHPs before. The aim of this study was to investigate whether somatosensory-evoked potentials (SEPs) can be monitored in common marmosets by the use of electrical stimulation of the skin and biotelemetric EEG devices in order to make a first step in studying the efficacy of analgesics in NHPs. With use of noxious electrical stimulation of the skin peripheral somatosensory nociceptive A-delta fibers were activated in isoflurane-anesthetized marmosets, which resulted in nociception-related electroencephalographic SEPs. After testing two marmosets no SEPs could be monitored, where after the decision was made to stop this study. In the first marmoset, the waveforms’ stimulus artefact was too broad for the SEP to appear. The second marmoset did not show any stimulus artefact or SEP in the waveforms at all. This all could be due to the used biotelemetric devices, such as the small bandwidth of the F40-EET transmitter or the insensitivity of the receiver. This pilot study proved that the used biotelemetry devices are not suitable for monitoring and recording SEPs at this moment because of technical limitations.