Topographic distribution of the EEG ad hoc broad bands during sleep and wakefulness in the spider monkey (Ateles Geoffroyi)

Abstract

There is evidence that research on sleep among New World monkeys may provide important knowledge related to the evolution of sleep more broadly in the primate order. Digital electroencephalographic (EEG) analyses provide essential knowledge on sleep in the spider monkey. Recently, specific EEG bands related to sleep in these animals have been obtained using principal component analysis, but the exact spatio-temporal distribution of these EEG bands in this species has not yet been analyzed. This study determined the topographic distribution of the EEG spectral power of ad hoc broad bands during rapid eye movement sleep, nonrapid eye movement sleep, and wakefulness. Superficial EEG activity was obtained from the occipital, frontal, and central areas of six young adult male monkeys housed in a laboratory. During wakefulness, occipital areas showed high absolute power in the 1-3, 3-12, and 11-30 Hz ranges, while during nonrapid eye movement 1 sleep the highest absolute power was in the 13-30 Hz range. During nonrapid eye movement 3 sleep, frontal and central areas showed a high absolute power in the 18-19 Hz range. Finally, the right central area showed a high absolute power in the 20-30 Hz range during rapid eye movement sleep. This topographic distribution of EEG bands could represent the brain organization required for arousal and mnemonic processing during sleep in the spider monkey.

New bands in the sleep stages of spider monkeys (Ateles geoffroyi): Electroencephalographic correlations and spatial distribution

“…In primates, specifically in rhesus macaques ( Macaca mulatta ), Bimbi et al (2018) reported that during the execution and observation of tasks, EEG activity in the ventral premotor area was associated with changes in the beta band of the central electrodes. Moreover, during REM sleep in spider monkeys, Hernández‐Arteaga et al (2021) found a higher correlation of the alpha band between the F3 and O1–O2 derivations, suggesting that this higher synchronization could represent an arousal state during sleep. In fact, distinct degrees of synchronization between frontal and posterior cortical areas have been reported in humans while solving complex mathematical problems (Molina del Río et al, 2019) or executing working memory tasks (Sarnthein et al, 1998; Sauseng et al, 2005).…”

“…Given (i) that EEG correlations provide measures of the extent of synchronization between two brain regions, and (ii) that coordinated functionality between areas drives certain processes-some cognitive, others behavioral-we designed a study using data gathered previously by PCA with spider monkeys (Cruz-Aguilar et al, 2020) to identify the spatial distribution of the correlations of ad hoc wide bands during the phases of the sleep-wake cycle. Taking into account previous studies of sleep in this species (Cruz-Aguilar et al, 2015;Cruz-Aguilar et al, 2020;Hernández-Arteaga et al, 2021), and earlier topographic EEG sleep studies (Hernández-Arteaga et al, 2021;Tanaka et al, 1999Tanaka et al, , 2000Werth et al, 1996;Zeitlhofer et al, 1993), we hypothesized that the correlations between different cortical regions will change in response to the novel EEG wide bands as follows, depending on the precise sleep-wake state:…”

“…For example, spider monkeys have elongated arms and fingers, hook‐like hands, and lack of external thumb (Fleagle, 2013; Schmitt et al, 2005; Tague, 1997). According to some authors, the arboreal life of prehensile‐tailed monkeys fostered the development of brain processes to detect predation dangers and maintain the vertical semifetal resting posture during sleep (Cruz‐Aguilar et al, 2015; Cruz‐Aguilar, Guevara, et al, 2018; Cruz‐Aguilar, Hernández‐González, et al, 2018; Cruz‐Aguilar et al, 2020; Hernández‐Arteaga et al, 2021).…”

“…Previous research suggests that specific cortical regions may encompass the wide EEG bands involved in arboreal body postures (Cruz‐Aguilar, Guevara, et al, 2018) and arousal regulation in these monkeys (Cruz‐Aguilar, Hernández‐González, et al, 2018). Hernández‐Arteaga et al (2021), for example, recently analyzed the topographic distribution of the EEG spectral power of new EEG bands in this species, finding that certain ones predominated in different cortical areas depending on the phases of wakefulness and sleep. However, the spatial distribution of EEG correlations of ad hoc wide bands during these conditions in this species has not been studied.…”