Biology subjects

Desai, N. P.

Publications and source records attributed to Desai, N. P..

3 recordsLinked to original sources

bioRxiv2026

Increased CSF volume, altered brain development and emotional reactivity after postnatal Zika virus infection in infant rhesus macaques

Although congenital Zika virus (ZIKV) syndrome is well-characterized, the neurodevelopmental consequences of postnatal infection are less understood. Here we used a rhesus macaque model to investigate the developmental consequences of ZIKV infection during infancy on the brain and behavior, building on our prior research. Male and female infant rhesus macaques infected with ZIKV at 1 month of age were compared to sex-, age-, and rearing-matched uninfected controls and infants treated with the TLR3 agonist PolyIC as a control for activation of the innate immune system. Longitudinal behavioral assessments revealed alterations in emotional regulation following ZIKV exposure, including poor state control scores obtained from the Infant Neurobehavioral Assessment Scale early after ZIKV infection and longer-term displays of increased hostility during an acute stressor. While attachment bonds to caregivers were preserved, ZIKV-infected infants showed sex-specific alterations in behavioral regulation during caregiver separation compared to controls. At 3 months of age, MRI scans revealed larger total cerebrospinal fluid (CSF) volume and reduced volumes in visual processing regions in ZIKV-infected infants compared to controls. Postnatal ZIKV exposure also resulted in sex-specific brain structural alterations with males exhibiting amygdala hypertrophy, whereas ZIKV-infected females had volumetric reductions in temporal-limbic and temporal-auditory cortices. These findings demonstrate that postnatal ZIKV infection disrupts the development of sensory, social and emotion-regulatory systems and CSF function, highlighting the critical need for long-term monitoring of exposed children. One-Sentence SummaryPostnatal Zika virus infection disrupts emotional regulation and alters brain development in infant rhesus macaques, revealing a critical window of neurodevelopmental vulnerability that extends beyond the fetal period.

neuroscience↗

bioRxiv2021

Chimpanzee pant-hoots encode information about individual but not group differences

Vocal learning, the ability to voluntarily modify the acoustic structure of vocalizations based on social cues, is a fundamental feature of speech in humans (Homo sapiens). While vocal learning is common in taxa such as songbirds and whales, the vocal learning capacities of nonhuman primates appear more limited. Intriguingly, evidence for vocal learning has been reported in chimpanzees (Pan troglodytes), for example in the form of regional variation ( dialects) in the pant-hoot calls. This suggests that some capacity for vocal learning may be an ancient feature of the Pan-Homo clade. Nonetheless, reported differences have been subtle, with inter-community variation representing only a small portion of the total acoustic variation. To gain further insights into the extent of regional variation in chimpanzee vocalizations, we performed an analysis of pant-hoots from chimpanzees in the neighboring Kasekela and Mitumba communities at Gombe National Park, Tanzania, and the geographically distant Kanyawara community at Kibale National Park, Uganda. We observed group differences only among the geographically isolated communities and did not find any differences between the neighboring communities at Gombe. Furthermore, we found differences among individuals in all communities. Hence, the variation in chimpanzee pant-hoots reflected individual differences, rather than group differences. The limited evidences for vocal learning in Pan suggest that extensive vocal learning emerged in the human lineage after the divergence from Pan.

animal behavior and cognition↗

bioRxiv2020

Proprioceptive afferents differentially contribute to effortful perception of object heaviness and mass distribution

When humans handle a tool, such as a tennis racket or hammer, for the first time, they often wield it to determine its inertial properties, however, the mechanisms that contribute to perception of inertial properties are not fully understood. The goal of the present study was to investigate how proprioceptive afferents contribute to effortful perception of heaviness and mass distribution of a manually wielded object in the absence of vision. Blindfolded participants manually wielded a set of specially-designed experimental objects of different mass and mass distribution about the wrist at different wrist angles and wrist angular kinematics. By independently manipulating these variables, we aimed to elicit different levels of tonic and rhythmic activity in the muscle spindles of the wrist flexors and extensors and relate them to reported perceptual judgments of heaviness and length. Perception of heaviness and length were predominantly dependent on an objects static moment and the moment of inertia, respectively. Manipulations of wrist angle and wrist angular kinematics affected perceptual judgments of heaviness and length in relatively opposite ways. As for wrist angle, ulnar deviation consistently resulted in an object being perceived heavier but shorter. Compared to static holding, wielding the object resulted in it being perceived heavier but wielding did not affect perceived length. These results suggest that proprioceptive afferents differentially contribute to effortful perception of object heaviness and mass distribution.

neuroscience↗