Paracingulate Sulcus Length Is Shorter in Voice-Hearers Regardless of Need for Care

Hallucinations—while often considered an indication of mental illness—are commonly experienced by those without a need for clinical care. These nonclinical voice-hearers offer an opportunity to investigate hallucinations in the absence of confounds inherent to the clinical state. Recent work demonstrates an association between auditory verbal hallucinations (AVH) and structural variability in paracingulate sulcus (PCS) of medial prefrontal cortex in a clinical population. However, before PCS length may be considered a biomarker for clinical hallucination risk, it is necessary to investigate PCS structure in a nonclinical population of voice-hearers with AVH phenomenology similar to those of their clinical counterparts. In the current study, PCS length was measured from T1-weighted structural MRI scans of four groups of participants: (1) voice-hearers with a psychotic disorder (n = 15); (2) voice-hearers without a psychotic disorder (n = 15); (3) nonvoice-hearers with a psychotic disorder (n = 14); and (4) nonvoice-hearers without a psychotic disorder (n = 15). There was a main effect of AVH status—but not psychosis—on right PCS length, with no interaction of AVH and psychosis. Participants with AVH exhibited reduced right PCS length compared to participants without AVH (mean reduction = 8.8 mm, P < 0.05). While past studies have demonstrated decreased PCS length in clinical voice-hearers, ours is the first demonstration that shorter right PCS extends to nonclinical voice-hearers. Our findings support the hypothesis that differences in PCS length are related to the propensity to hear voices and not to illness, consistent with a continuum model of voice-hearing.     

Epigenetics explained: a topic “primer” for the epilepsy community by the ILAE Genetics/Epigenetics Task Force

Epigenetics refers broadly to processes that influence medium to long‐term gene expression by changing the readability and accessibility of the genetic code. The Neurobiology Commission of the International League Against Epilepsy (ILAE) recently convened a Task Force to explore and disseminate advances in epigenetics to better understand their role and intersection with genetics and the neurobiology of epilepsies and their co‐morbidities, and to accelerate translation of these findings into the development of better therapies. Here, we provide a topic primer on epigenetics, explaining the key processes and findings to date in experimental and human epilepsy. We review the growing list of genes with epigenetic functions that have been linked with epilepsy in humans. We consider potential practical applications, including using epigenetic signals as biomarkers for tissue‐ and biofluid‐based diagnostics and the prospects for developing epigenetic‐based treatments for epilepsy. We include a glossary of terms, FAQs and other supports to facilitate a broad understanding of the topic for the non‐expert. Last, we review the limitations, research gaps and the next challenges. In summary, epigenetic processes represent important mechanisms controlling the activity of genes, providing opportunities for insight into disease mechanisms, biomarkers and novel therapies for epilepsy.