Ortiz-Juza, M. M. | bioRxiv Science

bioRxiv2025

Pupil responses to social stimuli are associated with adaptive behaviors across the first 24 months of life

BackgroundPupil changes in response to well-controlled stimuli can be used to understand processes that regulate attention, learning, and arousal. This study investigates whether pupil dynamics to social stimuli are associated with concurrent adaptive behavior in typically developing infants. To accomplish this, we developed and assessed pupillary responses to Stimuli for Early Social Arousal and Motivation in Infants (SESAMI). MethodsA sample of forty-six typically developing children aged six to twenty-four months were exposed to SESAMI. Infants were presented with either dynamic social faces or non-social stimuli that controlled for luminance, motion, and auditory exposure. A multi-level mixed effects model was used to fit pupillary response functions (PRFs) that measure the change in pupil size over time as the infants fixate on either a socially dynamic face or a non-social control. This model produces separate social and non-social PRFs for both the population and each individual. An average individual deviation score from the population PRF was calculated separately for social and non-social trials yielding the pupil response index (PRI). Vineland Adaptive Behavior Scales (VABS) were regressed on social and non-social individual PRIs while controlling for age and average fixation time. We tested whether the social PRI was a statistically significant predictor of adaptive behavior by comparing the model predicted VABS scores with observed scores. ResultsAn increase in PRI to social stimuli was significantly associated with better adaptive behaviors in typically developing children between 6 and 24 months of age. ConclusionsSESAMI combined with pupillometry and multi-level mixed effects modeling, provides a novel and scalable framework for quantifying individual differences in pupil changes in response to social stimuli relative to a population-level baseline. By demonstrating that pupil response indices during social fixations predict adaptive behaviors, we lay the foundation to test how these measures may help identify infants with intellectual and developmental disorders.

physiology↗

bioRxiv2022

Prepronociceptin-expressing neurons in the extended amygdala signal darting away from an aversive odor

Dysregulation in the neural circuitry that encodes physiological arousal responses is thought to contribute to the manifestation of the maladaptive behaviors observed in neuropsychiatric disorders. We previously found that prepronociceptin-expressing neurons in the bed nucleus of the stria terminalis (PnocBNST neurons) modulate rapid changes in physiological arousal upon presentation of motivationally salient stimuli (Rodriguez-Romaguera et al., 2020). However, whether PnocBNST neurons are necessary to regulate behavioral actions to motivationally salient stimuli is still unknown. Here, we investigated the role of PnocBNST neurons in encoding behavioral responses to motivationally salient stimuli using in vivo calcium imaging and optogenetic approaches in freely behaving mice. We find that the bulk activity of PnocBNST neurons increases when mice are near an aversive odor in comparison to a rewarding odor. However, optogenetic inhibition of PnocBNST neurons does not affect the amount of time mice spend near an aversive odor. Further analysis revealed that a subgroup of PnocBNST neurons that correlate with proximity to the aversive odor also correlate to darting away from the same aversive odor. Since these two behaviors are opposite to each other and since we previously found PnocBNST neurons correlate with arousal responses, we believe these results may be due in part to the encoding of arousal responses that occur when mice approach and dart away from aversive stimuli.

neuroscience↗