Biology subjects

Gross, J. J.

Publications and source records attributed to Gross, J. J..

4 recordsLinked to original sources

bioRxiv2026

Amygdala Persistence in Aging: Replication and Extension of Puccetti et al. (2021)

Age-related differences in affect are well established, but their neural mechanisms remain unclear. In a preregistered replication of Puccetti et al. (2021) and extension, we examined age, affect, left-amygdala negative persistence, and amygdala-ventromedial prefrontal cortex (vmPFC) task-based connectivity using MIDUS 3 daily diary and fMRI data. Older age predicted higher positive and lower negative affect in the daily diary sample (N = 1,168; ps < .001). In the primary diary + fMRI sample (N = 81; ages 48-95, 61.7% female, 82.7% White), greater persistence predicted higher raw negative affect ({beta} = 0.278, 95% CI [0.012, 0.544], p = .020); associations with positive and log-transformed negative affect were nonsignificant (ps [≥] .063). Older age predicted lower persistence in the final fMRI sample (N = 127; {beta} = -0.00260, 95% CI [-0.00504, -0.00016], p = .018), but this association was weaker in the primary diary + fMRI sample (p = .200), with no evidence of mediation. Greater anterior vmPFC connectivity predicted lower raw negative affect ({beta} = -0.106, 95% CI [-0.223, 0.012], p = .039) and log-transformed negative affect (p = .014). In MIDUS Refresher 1, affect estimates were directionally similar but nonsignificant (N = 48; ps [≥] .081), whereas the age-persistence estimate reversed direction. These findings provide partial support for amygdala persistence and task-based connectivity as neural correlates of daily affect, while highlighting variability in the magnitude and replicability of fMRI-behavior associations.

neuroscience↗

bioRxiv2022

A translational approach to measuring the neural systems underlying approach-avoidance conflict in humans

Approach-avoidance conflict (AAC) arises from decisions with embedded positive and negative outcomes, and appropriate management of these decisions is essential for adaptive functioning. However, translating key advances on AAC in non-human primates to tasks in humans has proven difficult in part due to the inherent limitations in existing human tasks in isolating relevant neural substrates of behavior. Here, we present, and validate, a novel task in humans (N= 38) of both sexes, derived from work in non-human primates utilizing primary reinforcers (shock/juice), and in doing so identify neural features specific to conflict, implementing a computational model of task behavior. We found that neural patterns of activation within the parietal, frontal, temporal and cingulate regions were associated with conflict-specific avoidance behavior. Importantly, a number of these regions were associated with trait anxiety, implicating a potential link between these neural regions and anxiety-driven avoidance behavior. This task platform may help advance both behavioral and biological research examining the neural patterning underlying approach-avoidance behavior in humans, providing an empirically oriented framework with which to translate between non-human primate and human work. Significance StatementThe current paper describes and validates a novel task for studying Approach-Avoidance Conflict behavior that capitalizes on innate reinforcers and stringent thresholding, effectively bridging animal and human work in this field. The task is then used to identify the neural correlates of AAC behavior in humans, identifying patterns of activation linked to temporal variation in avoidance behavior specific to conflict. Further, a novel model is developed and applied to the behavioral data to more sensitively quantify response patterns using reinforcement learning, and neural patterns relating to these behavioral effects were identified. Finally, as anxiety is strongly associated in the animal and human literature with avoidance responding, we identified a subgroup of neural effects associated with trait anxiety.

neuroscience↗

bioRxiv2020

Neurocognitive Heterogeneity in Social Anxiety Disorder: The Role of Self-Referential Processing and Childhood Maltreatment

Social anxiety disorder (SAD) is characterized by negative self-beliefs and altered brain activation in the default mode network (DMN). However, the extent to which there is neurocognitive heterogeneity in SAD remains unclear. We had two independent samples of patients perform a self-referential encoding task, and complete self-reports of childhood maltreatment, subjective well-being, and emotion regulation. In the replication sample, we also measured DMN activation using functional magnetic resonance imaging. K-means clustering revealed two distinct sub-groups of SAD patients in the discovery sample. Cluster 1 demonstrated higher levels of negative and lower levels of positive self-referential trait endorsement, and significantly higher levels of childhood emotional maltreatment, lower subjective well-being, and altered emotion regulation strategy use. A similar pattern was observed in the replication sample, which further demonstrated higher DMN activation during negative trait judgments in cluster 1. These findings reveal neurocognitive heterogeneity in SAD and its relationship to emotional maltreatment.

neuroscience↗

bioRxiv2018

Prevalence of subclinical ketosis and production diseases in dairy cows in Central and South America, Africa, Asia, Australia and New Zealand, and Eastern Europe

Subclinical ketosis (SCK) and periparturient diseases considerably account for economic and welfare losses in dairy cows. The majority of scientific reports investigating the prevalence of SCK and production diseases are based on empirical studies conducted in Western Europe and North America. The present study surveyed the prevalence of SCK and production-related clinical diseases in early lactating cows in various countries across the world other than those in North America and Western Europe. Twelve countries of South and Central America (Argentina, Brazil, Chile, Colombia, Mexico), Africa (South Africa), Asia (Thailand, China), Eastern Europe (Russia, Ukraine), Australia and New Zealand were assessed, and data from a total of 8,902 cows kept at 541 commercial dairy farms were obtained. A minimum of 5 cows per farm were blood sampled and examined once after parturition up to day 21 of lactation. Blood concentration of {beta}-hydroxybutyrate (BHBA) was measured (threshold for SCK: 1.2 mmol/l) and the presence of production-related diseases such as milk fever, retained placenta, mastitis, metritis, displaced abomasum, claw disease and clinical ketosis was recorded. More than 95% of all cows were examined in their second week of lactation. Across all investigated countries, the SCK prevalence was 24.1%, ranging from 8.3% up to 40.1%. The prevalence of production-related diseases detected during the first 21 days of lactation was relatively low (< 5%). Calculated odds ratios did not indicate an elevated risk for production diseases in cows with SCK. Despite differences in production systems across countries and variation between individual farms within a region, the present study data on SCK prevalence align with observations in Western European and North American dairy herds. At the very early stage of sampling and clinical examination for detection of SCK, it cannot be excluded that certain production diseases such as DA, lameness and mastitis have developed later.

physiology↗