Kanthi, A. | Search bioRxiv

bioRxiv2026

Microstate Dynamics of Focused Attention Meditation

Focused-attention meditation provides a tractable model for examining how large-scale brain dynamics support attention and self-regulation. Using high-density EEG microstate analysis, we investigated how focused-attention meditation on the breath ([A]n[a]p[a]nasati) modulates intrinsic brain activity in 22 experienced practitioners, compared with baseline rest and deliberate mental imagery. Five canonical microstate classes (A-E) were identified. Meditation produced a robust reduction of Microstate C across coverage, duration, and occurrence, accompanied by increased presence of Microstates D and E (all Microstate x Condition interactions p < 0.0001). Source localization revealed that Microstate C was generated primarily in medial and lateral temporal regions including the hippocampus and parahippocampal cortex, whereas Microstate D involved posterior midline regions including the posterior cingulate cortex and precuneus, and Microstate E engaged frontoparietal and orbitolimbic networks. Together, these results indicate that focused-attention meditation reorganizes the temporal architecture of large-scale brain dynamics by downregulating microstate patterns associated with self-referential and memory-based processing while enhancing neural states supporting attentional stability and internal monitoring.

neuroscience↗

bioRxiv2016

Homozygous c.259G>A variant in ISCA1 is associated with a new multiple mitochondrial dysfunctions syndrome

The iron-sulfur (Fe-S) cluster (ISC) biogenesis pathway is indispensable for many fundamental biological processes and pathogenic variations in genes encoding several components of the Fe-S biogenesis machinery, such as NFU1, BOLA3, IBA57 and ISCA2 are already implicated in causing four types of multiple mitochondrial dysfunctions syndromes (MMDS) among other human diseases. MMDS are clinically characterized by neurodevelopmental delay, neurological deterioration, lactic acidosis, extensive white matter abnormalities and early death. We report on two unrelated families, with two affected children each with neurodevelopmental delay, regression of developmental milestones, seizures, extensive white matter abnormalities, cortical migrational abnormalities, lactic acidosis and early demise. Exome sequencing of two affected individuals, one from each family, revealed a homozygous c.259G>A variant in ISCA1 and Mendelian segregation was confirmed in both families. ISCA1 is a specialized factor known to mediate maturation of distinct Fe-S cluster (ISC) proteins. In silico functional analyses and structural modeling of the protein predict the identified ISCA1 variant to be detrimental to protein stability and function. Notably the phenotype observed in all affected subjects with the ISCA1 pathogenic variant is similar to that previously described in all 4 types of MMDS. The ISCA1 variant lies in the only shared region of homozygosity between the two families suggesting the possibility of a founder effect. To the best of our knowledge this is the first instance where ISCA1 deficiency has been shown to be associated with a human disease, a new type of multiple mitochondrial dysfunctions syndrome.

genetics↗