Biology subjects

Curzon, M.

Publications and source records attributed to Curzon, M..

3 recordsLinked to original sources

bioRxiv2025

Brain Microstructure and Obesity Risk in Early Childhood: Insights from Restriction Spectrum Imaging

Pediatric obesity is a growing public health concern, yet little is known about the neurobiological underpinnings of obesity risk in early childhood. Using restriction spectrum imaging (RSI), we examined associations between adiposity and brain microstructure in a cross-sectional sample of 159 children aged 4-7 years, including 81 with ADHD and 78 typically developing (TD) peers. We focused on RSI-derived measures of restricted diffusion--specifically restricted normalized isotropic (RNI), directional (RND), and total (RNT) signals--as indicators of cellular density in subcortical and cortical regions implicated in reward and salience processing. Body mass index (BMI), percent body fat, waist circumference, and obesity status were assessed. Higher BMI, but not other adiposity measures, was significantly associated with increased RNI in the right insula, nucleus accumbens (NAcc), and putamen, as well as increased RNT in the right insula and pallidum. These findings suggest early microstructural alterations in reward-related circuits, consistent with theories of diet-related neuroinflammation. Contrary to hypotheses, ADHD diagnosis did not moderate the associations, and anthropometric profiles were similar between groups. This suggests a shared neural pathway linking early adiposity and brain structure, independent of diagnostic status. Our findings replicate and extend prior work in older children, highlighting BMI as the most sensitive marker of obesity-related brain differences in early childhood. These results underscore the potential of RSI as a tool for identifying early neural risk markers of obesity and inform future efforts to design preventive interventions during critical developmental windows.

neuroscience↗

bioRxiv2024

Structural Development of Speech Networks in Young Children at Risk for Speech Disorder

Characterizing the structural development of the neural speech network in early childhood is important to understand speech acquisition. To investigate speech in the developing brain, 94 children aged 4-7-years-old were scanned using diffusion weighted imaging (DWI) magnetic resonance imaging (MRI). In order to increase sample size and performance variability, we included children who were diagnosed with attention-deficit hyperactivity disorder (ADHD) from a larger ongoing study. Additionally, each child completed the Syllable Repetition Task (SRT), a validated measure of phoneme articulation. The DWI data were modeled using restriction spectrum imaging (RSI) to measure restricted and hindered diffusion properties in both grey and white matter. Consequently, we analyzed the diffusion data using both whole brain analysis, and automated fiber quantification (AFQ) analysis to establish tract profiles for each of six fiber pathways thought to be important for supporting speech development. In the whole brain analysis, we found that SRT performance was associated with restricted diffusion in bilateral inferior frontal gyrus, pars opercularis, right pre-supplementary and supplementary motor area, and bilateral cerebellar grey matter (p < .005). Age moderated these associations in left pars opercularis and frontal aslant tract (FAT). However, in both cases only the cerebellar findings survived a cluster correction. We also found associations between SRT performance and restricted diffusion in cortical association fiber pathways, especially left FAT, and in the cerebellar peduncles. Analyses using automated fiber quantification (AFQ) highlighted differences in high and low performing children along specific tract profiles, most notably in left but not right FAT, in bilateral SLFIII, and in the cerebellar peduncles. These findings suggest that individual differences in speech performance are reflected in structural grey and white matter differences as measured by restricted and hindered diffusion metrics, and offer important insights into developing brain networks supporting speech in very young children.

neuroscience↗

bioRxiv2024

Reduced recruitment of inhibitory control regions in very young children with ADHD during a modified Kiddie Continuous Performance Task: a fMRI study.

Attention-Deficit/Hyperactivity Disorder (ADHD) symptom profiles are known to undergo changes throughout development, rendering the neurobiological assessment of ADHD challenging across different developmental stages. Particularly in young children (ages 4 to 7 years), measuring inhibitory control network activity in the brain has been a formidable task due to the lack of child-friendly functional Magnetic Resonance Imaging (fMRI) paradigms. This study aims to address these difficulties by focusing on measuring inhibitory control in very young children within the MRI environment. A total of 56 children diagnosed with ADHD and 78 typically developing (TD) 4-7-year-old children were examined using a modified version of the Kiddie-Continuous Performance Test (K-CPT) during BOLD fMRI to assess inhibitory control. We concurrently evaluated their performance on the established and standardized K-CPT outside the MRI scanner. Our findings suggest that the modified K-CPT effectively elicited robust and expected brain activity related to inhibitory control in both groups. Comparisons between the two groups revealed subtle differences in brain activity, primarily observed in regions associated with inhibitory control, such as the inferior frontal gyrus, anterior insula, dorsal striatum, medial pre-supplementary motor area (pre-SMA), and cingulate cortex. Notably, increased activity in the right anterior insula was associated with improved response time (RT) and reduced RT variability on the K-CPT administered outside the MRI environment, although this did not survive statistical correction for multiple comparisons. In conclusion, our study successfully overcame the challenges of measuring inhibitory control in very young children within the MRI environment by utilizing a modified K-CPT during BOLD fMRI. These findings shed light on the neurobiological correlates of inhibitory control in ADHD and TD children, provide valuable insights for understanding ADHD across development, and potentially inform ADHD diagnosis and intervention strategies. The research also highlights remaining challenges with task fMRI in very young clinical samples.

neuroscience↗