Cortical beta EEG oscillations related to changes in muscle tone activity during sleep in spider monkey (Ateles geoffroyi)

Abstract

The left motor cortex, through beta2 band activity, interacts with abductor caudae medialis muscle tonicity during delta sleep. This interaction takes part in the mechanisms that regulate the sleep postures.

Alpha electroencephalographic activity during rapid eye movement sleep in the spider monkey (Ateles geoffroyi): An index of arousal during sleep?

“…REMS consists of relatively low‐voltage, mixed‐frequency (2.0–7.0 Hz) EEG with episodic rapid eye movements and absent or reduced chin EMG activity. However, as previous studies have shown (Cruz‐Aguilar et al, , ), REMS in the spider monkey does not feature chin EMG atonia. For this reason, the current study did not consider muscular atonia for REMS in either the FMM or ACMM muscles.…”

“…This is the first study to characterize the prevalence and coherence of the theta, alpha, and beta rhythms in different cortical areas during wakefulness and sleep in spider monkeys. Considering that alpha activity during sleep is an indicator of arousal and cortical activation (American Sleep Disorders Association, ; Cantero et al, ; Hasan & Broughton, ; Pivik & Harman, ; Tyson et al, ), that muscle atonia is not observed in spider monkeys during REMS, and that these primates sleep in a vertical position (Cruz‐Aguilar et al, , ), we hypothesized higher RP and EEG coherence of the alpha band during REMS compared with N‐REMS. Likewise, we predicted that these features of EEG alpha activity would be accompanied by the vertical posture and lack of muscular atonia during REMS.…”

“…A branch from a Dialium guianense tree was placed transversely inside the cage at a height of 40″ so that the animals could sleep in their natural posture during PSG recording. The electrophysiological and behavioral data for the study are derived from the data set used by Cruz‐Aguilar et al ().…”

“…The results showed a direct relation between the beta2 band of the left motor cortex and tail muscle tonicity, mainly during Delta sleep. This interaction could be part of the mechanisms that regulate sleep postures in this species (Cruz‐Aguilar et al, ). However, many aspects of sleep in arboreal primates require further study, as do the ways in which sleeping primates monitor and respond to potential predatory threats.…”

“…These observations could suggest that arboreal primates have developed an adaptive neuromuscular mechanism for sleep that decreases the risk of suffering predation while in this state. In light of these findings, Cruz‐Aguilar et al () evaluated the neuromuscular interaction related to sleeping posture in an arboreal primate. For this purpose, a noninvasive PSG study of six spider monkeys was conducted under laboratory conditions.…”