Biology subjects

Schiller, K.

Publications and source records attributed to Schiller, K..

3 recordsLinked to original sources

bioRxiv2026

HIPPOCAMPAL TAU RELATED SIGNAL INDEXES HYPEREXCITABILITY AND NREM SLEEP MEMORY DYSFUNCTION IN TEMPORAL LOBE EPILEPSY

Background Sleep and memory disturbances are common in temporal lobe epilepsy (TLE), yet their relationship with tau-targeted neuroimaging measures remains unclear. We investigated whether in-vivo temporal 18F-MK6240 tracer retention relates to seizure burden, non-rapid eye movement (NREM) sleep microstructure, and memory performance in TLE. Methods This cross-sectional study was conducted from 2019 to 2024 at the Montreal Neurological Institute-Hospital. Eligible patients had unilateral TLE diagnosed according to International League Against Epilepsy criteria and underwent overnight electroencephalography (EEG) recordings, research-protocol 3T magnetic resonance imaging, and 18F-MK6240 positron emission tomography. Regional 18F-MK6240 standardized uptake value ratios (SUVRs), using the cerebellum as the reference region, were quantified in the ipsilateral hippocampus (defined a priori as the primary region of interest), as well as in peri-hippocampal and lateral temporal regions. Electroclinical and neuropsychological measures, including seizure burden (high vs low), N2 interictal epileptiform discharge frequency (frequent vs non-frequent), and memory performance (impaired vs intact), were classified according to predefined clinical criteria. N2 spindle rate and N3 slow-wave rate were quantified from overnight EEG recordings. Findings Of 70 eligible patients, 25 were included (eight [32%] females; mean age 35.2 years [SD 12.1]). Higher ipsilateral hippocampal 18F-MK6240 uptake was observed in participants with greater focal seizure burden (median [IQR] 0.70 [0.67-0.78] vs 0.64 [0.58-0.65], rank-biserial correlation=-0.58, 95% CI -0.82 to -0.19; p=0.02), was associated with lower N2 spindle rate (r=-0.42, 95% CI -0.70 to -0.03; p=0.04) and higher N3 slow-wave rate (r=0.47; 95% CI 0.09 to 0.73; p=0.02), and was also higher in participants with impaired than intact memory performance (n=21; mean [SD] 0.80 [0.12] vs 0.68 [0.10], Cohen's d=1.15, 95% CI 0.07 to 2.21; p=0.04). Associations outside the hippocampus were generally less consistent and less precise, with the largest non-hippocampal estimate observed in peri-hippocampal regions. Interpretation Higher hippocampal 18F-MK6240 uptake was associated with greater focal seizure burden, altered NREM sleep microstructure, and impaired memory performance in TLE. These findings suggest that hippocampal 18F-MK6240 uptake may represent a candidate marker of circuit vulnerability associated with NREM sleep-memory dysfunction in TLE, warranting validation in larger longitudinal studies.

neuroscience↗

bioRxiv2025

Time- and space-resolved regulatory circuits in Arabidopsis thaliana

O_LIGeneral metabolism and responses to internal or external signals are tightly regulated in plants. We hypothesize that a network of intermediate regulatory proteins including transcription factors, kinases, and E3 ligases connect input signals like light, temperature, circadian clock, and ontogenetic pathways to output pathways. We therefore investigate the transcriptional dynamics of these regulators. C_LIO_LIRNA sequencing was performed on three-week-old Arabidopsis thaliana Col-0 rosettes grown under 12h/12h light/dark conditions sampled every two hours over 24 hours to match publicly available single cell data of same age plants. Both were analyzed to identify the abundance of intermediate regulators in time and space. C_LIO_LIIntermediate regulators are of significantly lower abundance compared to other transcripts in the Arabidopsis transcriptome. More than half of expressed kinases, E3 ligases and transcriptions factors vary in either time, space or both in mature leaves. C_LIO_LIDynamic expression patterns of regulators allow plants to maintain tightly regulated metabolism while providing sufficient room for specific stress responses. High plasticity of the Arabidopsis transcriptome highlights the importance of considering sampling time-of-day and cellular resolution for experiments. C_LI One sentence summaryExpression patterns in time and space of kinases, E3 ligases and transcription factors in Arabidopsis thaliana provide ample room for dynamic and specific regulation of metabolism and stress responses.

plant biology↗

bioRxiv2024

Regulation of Crassulacean Acid Metabolism at the protein level in the CAM plant Kalanchoë laxiflora

Crassulacean acid metabolism (CAM) is an adaptation to environments where water availability is seasonal or extremely low. It serves to ensure survival and/ or maintain productivity in these adverse environments. CAM has repeatedly evolved although it requires a large and complex set of enzymes and transporters and regulatory processes to control metabolite flux and pools. To test potential regulatory levels, we analyze the CAM plant Kalanchoe laxiflora embedded in the context of available CAM genome and transcriptome sequences. We show that CAM associated transcripts and proteins do not show a binary on/off pattern between day and night in K. laxiflora. Instead, we observe that many CAM plants display shared amino acid changes compared to C3 plants especially in starch metabolism. Phosphoproteomics identifies phosphoproteome changes in K. laxiflora between day and night. Taken together, the analyses demonstrate the CAM photosynthesis is regulated at the levels of transcripts and proteins. One sentence summaryRegulation of CAM cannot be explained by transcript and protein abundance alone but is also dependent on adaptive changes in proteins and posttranslational modifications.

plant biology↗