Caracterização comportamental da coruja-buraqueira como modelo aviário para investigação das bases neurais e farmacológicas do piscar espontâneo

Abstract

Eye blinking is characterized by the rapid closing and reopening of the eyelids causing a brief moment of loss of visual information. This movement occurs as a reflex, to maintain corneal homeostasis, as well as spontaneously. Research in mammals, mainly primates, has shown that the rate of spontaneous blinking is related to dopaminergic control of cognitive and attentional processes. Although we do not know the neural mechanism behind this association, it is known that the dopaminergic system is highly conserved throughout vertebrate evolution. Based on this argument, our work proposes the burrowing owl (Athene cunicularia) as a new animal model to study this behavior. We recorded the blinking behavior of six animals over a 24-hour period and conducted a temporal analysis of their blinking patterns. Because it is a cathemeral species, this animal alternates between periods of wakefulness and sleep throughout the day and night, allowing us to examine how central states and exogenous factors contribute to the dynamics of this behavior. Eye blinks were sampled as discrete events (temporal resolution: 1Hz). Time series were compiled for blinks accompanied by head saccades and from blinks occurring alone (isolated blinks). Over the 24 hours, the median rate (IQR - inter-quartile range) was 1.77 (IQR, 0.55) for saccade-associated blinks and 0.21 (IQR, 0.28) events/min for isolated blinks. Using a circular model selection approach, we found that the distribution of daily blinks was not uniform and was better fitted by Von Mises-based models that incorporate at least one peak in the afternoon. There was no significant difference in mean afternoon peak hours between blink with saccade and isolated blinking (Watson-Williams test, F = 0.0787, p = 0.7847). To characterize the temporal structure of each time series, we computed the burstiness parameter B based on the inter-blink time distribution and the memory parameter M based on the inter-blink time correlations metrics. From this analysis, we found that the occurrence of blinking events is neither periodic nor random but follows an intermittent dynamics that is primarily driven by a strong short-term memory effect. Moreover, our findings demonstrated that sleep deprivation has a more significant impact on isolated blinks than those occurring in conjunction with saccades. In any case, the comparison between the pre- and post-deprivation periods showed that the temporal dynamics of blinking are preserved even after sleep deprivation.