Biology subjects

Pitts, S.

Publications and source records attributed to Pitts, S..

2 recordsLinked to original sources

bioRxiv2023

Neural Interoceptive Processing is Modulated by Deep Brain Stimulation for Treatment Resistant Depression

BackgroundA critical advance in depression research is to clarify the hypothesized role of interoceptive processing in neural mechanisms of treatment efficacy. This study tests whether cortical interoceptive processing, as indexed by the heartbeat-evoked potential (HEP), is modulated by deep brain stimulation (DBS) to the subcallosal cingulate (SCC) for treatment resistant depression (TRD). MethodsEight patients with TRD were enrolled in a study of SCC DBS safety and efficacy. Electroencephalography (EEG) and symptom severity measures were sampled in a laboratory setting over the course of a six-month treatment protocol. The primary outcome measure was an EEG-derived HEP, which reflects cortical processing of heartbeat sensation. Cluster-based permutation analyses were used to test the effect of stimulation and time in treatment on the HEP. The change in signal magnitude after treatment was correlated with change in depression severity as measured by the 17-item Hamilton Depression Rating Scale. ResultsHEP amplitude was greater after 24 weeks of treatment (t(7)=-4.40, p=.003, g=-1.38, 95% Cl [-2.3, -0.42]), and this change was inversely correlated with latency of treatment response (rho = -0.75, 95% Cl [-0.95, -0.11], p=.03). An acute effect of DBS was also observed, but as a decrease in HEP amplitude (t(6) =6.66, p<.001, g=2.19, 95% Cl [0.81, 3.54]). HEP differences were most pronounced over left posterior sensors from 405-425 ms post-stimulus. ConclusionBrain-based evidence substantiates a theorized link between interoception and depression, and suggests an interoceptive contribution to the mechanism of treatment efficacy with deep brain stimulation for severe depression.

neuroscience↗

bioRxiv2021

Widespread germline genetic heterogeneity of human ribosomal RNA genes

Polymorphism drives survival under stress and provides adaptability. Genetic polymorphism of ribosomal RNA (rRNA) genes derives from internal repeat variation of this multicopy gene, and from interindividual variation. A considerable amount of rRNA sequence heterogeneity has been proposed but has been challenging to estimate given the scarcity of accurate reference sequences. We identified four rDNA copies on chromosome 21 (GRCh38) with 99% similarity to recently introduced reference sequence KY962518.1. Pairwise alignment of the rRNA coding sequences of these copies showed differences in sequence and length. We customized a GATK bioinformatics pipeline using the four rDNA loci, spanning a total 145 kb, for variant calling. We employed whole genome sequencing (WGS) data from the 1000 Genomes Project phase 3 and analyzed variants in 2,504 individuals from 26 populations. Using the pipeline, we identified a total of 3,790 variant positions. The variants positioned non-randomly on the rRNA gene. Invariant regions included the promoter, early 5 ETS, 5.8S, ITS1 and certain regions of the 28S rRNA, and large areas of the intragenic spacer. 18S rRNA coding region had very few variants, while a total of 470 variant positions were observed on 28S rRNA. The majority of the 28S rRNA variants located on highly flexible human-expanded rRNA helical folds ES7L and ES27L, suggesting that these represent positions of diversity and are potentially under continuous evolution. These findings provide a genetic view for rRNA heterogeneity and raise the need to functional assess how the 28S rRNA variants affect ribosome functions.

bioinformatics↗