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Zucker, R.

Publications and source records attributed to Zucker, R..

2 recordsLinked to original sources

Cognitive modeling informs interpretation of go/no-go task-related neural activations and their links to externalizing psychopathology

BackgroundIndividuals with ADHD and other forms of externalizing psychopathology tend to display poor behavioral performance on the go/no-go task, which is thought to reflect deficits in inhibitory control. However, clinical neuroimaging studies using this paradigm have yielded conflicting results, raising basic questions about what the task measures and which aspects of the task relate to clinical outcomes of interest. We aimed to provide a clearer understanding of how neural activations from this paradigm relate to the cognitive mechanisms that underlie performance and the implications of these relationships for clinical research.\n\nMethods143 emerging adults (ages 18-21) performed the go/no-go task during fMRI scanning. We used the diffusion decision model (DDM), a mathematical modeling approach, to quantify distinct neurocognitive processes that underlie go/no-go performance. We then correlated DDM parameters with brain activation across several standard go/no-go contrasts and assessed relationships of DDM parameters and associated neural measures with clinical ratings.\n\nResultsFronto-parietal activations on correct inhibition trials, which have typically been assumed to isolate neural processes involved in inhibition, were unrelated to either individuals response biases or their efficiency of task performance. In contrast, responses to false alarms in brain regions putatively responsible for error monitoring were strongly related to more efficient performance on the task and correlated with externalizing behavior and ADHD symptoms.\n\nConclusionsOur findings cast doubt on conventional interpretations of go/no-go task-related activations as reflecting inhibition functioning. We instead find that error-related contrasts provide clinically-relevant information about neural systems involved in monitoring and optimizing cognitive performance.

neuroscience↗

Asymmetrically Positioned Flagellar Control Units Regulate Human Sperm Rotation

The ability of sperm to fertilize an egg is controlled by ion channels, one of which is the pH-dependent calcium channel of sperm CatSper. For CatSper to be fully activated, the cytoplasmic pH must be alkaline, which is accomplished by either proton transporters, or a faster mechanism, such as the voltage-gated proton channel Hv1. To ensure effective regulation, these channels and regulatory proteins must be tightly compartmentalized. Here, we characterize human sperm nanodomains that are comprised of Hv1, CatSper and regulatory protein ABHD2. Super-resolution microscopy revealed that Hv1 forms asymmetrically positioned bilaterally distributed longitudinal lines that span the entire length of the sperm tail. Such a distribution provides a direct structural basis for the selective activation of CatSper, and subsequent flagellar rotation along the long axis that, together with hyperactivated motility, enhances sperm fertility. Indeed, Hv1 inhibition leads to a decrease in sperm rotation. Thus, sperm ion channels are organized in distinct regulatory nanodomains that control hyperactivated motility and rotation.

cell biology↗