Biology subjects

Mlynarski, W.

Publications and source records attributed to Mlynarski, W..

9 recordsLinked to original sources

bioRxiv2026

Intrinsic Population Dynamics are a Neuronal Substrate for Visual Attention

Perception results from a dynamic interplay between the feedforward processing of sensory stimuli and intrinsic neural activity 1, which is often dismissed as noise 2. To tailor perceptual processes to the organisms current needs on a continuous, moment-to-moment basis, intrinsic dynamics - rather than just being noise - have been suggested to reflect prior expectations 3,4, task demands 5, and attentional focus 6. Here, we identify a novel signature of attentive state in which intrinsic, collective neural activity modulates visuospatial attention by dynamically interacting with sensory input within the superior colliculus (SC), a midbrain hub that integrates bottom-up visual input with top-down signals 7. We show that these intrinsic dynamics organize cell activity into structured, blob-like features that are temporally and topographically localized and that rival sensory-evoked responses in strength. These features emerge as animals learn to engage in the visual detection task, and predict behavioral outcomes on a trial-by-trial basis. Although independent of sensory input or overt behavior, the features can be recruited to enhance visual responses four-fold in the attentive state, generating a "dynamic saliency map" that aligns with reaction times and behavioral outcomes. A computational model indicates that tunable blob-like features can arise from local excitatory-inhibitory interactions within the SC, and enhance sensory-evoked responses in line with observations. Together, our results identify state-dependent intrinsic population activity that interacts with sensory input to give rise to a saliency-map-like representation linked to flexible, goal-directed behavior.

neuroscience↗

bioRxiv2025

Single-cell profiling of CAR-T CD19 cell phenotypes and immune system dynamics in pediatric BCP-ALL

BackgroundChimeric Antigen Receptor T-cell (CAR-T) therapy targeting CD19 has transformed the treatment of relapsed/refractory B-cell precursor acute lymphoblastic leukemia (BCP-ALL). However, the phenotypic heterogeneity of CAR+ T-cells and their interactions with the immune system remain poorly understood. Here, we characterize CAR+ T-cell subsets and persistence in patients receiving standard-of-care tisagenlecleucel in an effort to optimize therapeutic efficacy in pediatric BCP-ALL. MethodsNineteen pediatric patients with relapsed/refractory BCP-ALL treated with tisagenlecleucel in Poland were included in the study. CAR+ T-cell composition and the peripheral blood mononuclear cell (PBMC) immune system were assessed using mass cytometry, with qPCR validation of CAR+ T-cells. Machine learning algorithms in R classified phenotypes. Statistical analyses examined associations between CAR+ T-cell subsets, immune system changes, and CAR-T therapy outcomes, including cytokine release syndrome (CRS). ResultsInfusion product analysis showed a predominance of CD4+ Central Memory (16.6%), MAIT/NKT (7.04%), and Treg memory (63.3%) cells, with high consistency between paired products. Post-infusion, CAR+ Treg memory cells declined to <1%, while CD8+ subsets expanded. PBMC immune system analysis revealed increased monocyte and NK cell counts post-infusion. Patients who experienced CRS had fewer classical monocytes at day 7 and fewer transitional monocytes at day 28. Early and late NK cells increased post-infusion in all patients. However, pre-infusion levels were lower in patients experiencing CRS. CRS correlated with higher CAR+ CD8+ Terminal Effector and MAIT/NKT frequencies in infusion products. While CAR+ composition was not linked to disease burden, prior treatments, or therapy outcomes, changes in monocyte and NK cell dynamics were associated with disease burden, relapse, and CRS. ConclusionsThis study provides a detailed characterization of CAR-T CD19 cell composition and post-infusion dynamics in pediatric BCP-ALL patients treated with tisagenlecleucel. Infusion products were predominantly CAR+ CD4+ T cells with a Central Memory phenotype, including a notable Treg memory subset that declined post-infusion. CAR+ CD8+ subsets expanded, coinciding with immune system shifts. These changes correlated with clinical responses, including CRS, highlighting the role of the immune system in CAR-T therapy outcomes and informing strategies to optimize treatment. Summary boxO_ST_ABSWHAT IS ALREADY KNOWN ON THIS TOPICC_ST_ABSCD19-targeted CAR-T therapy has revolutionized the treatment of relapsed/refractory pediatric BCP-ALL. While studies have examined the diverse composition of CAR-T infusion products in adult large B-cell lymphoma (LBCL), there is limited data in the pediatric BCP-ALL setting. WHAT THIS STUDY ADDSThis study demonstrates that standard-of-care CAR-T infusion products (tisagenlecleucel) are primarily composed of CAR+ CD4+ Central Memory and regulatory T cells, which decline post-infusion as CAR+ CD8+ subsets expand. Additionally, monocyte and NK cell dynamics are closely linked to cytokine release syndrome (CRS) and treatment outcomes, emphasizing the critical role of immune system interactions in CAR-T therapy efficacy. HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE, OR POLICYThese findings indicate that monitoring immune system shifts could enhance CRS risk assessment and improve patient stratification, leading to more personalized CAR-T therapy. Additionally, insights into CAR+ T-cell composition may guide the development of strategies to optimize CAR-T efficacy, potentially improving long-term treatment outcomes in pediatric BCP-ALL.

cancer biology↗

bioRxiv2022

Panoramic visual statistics shape retina-wide organization of receptive fields

Statistics of natural scenes are not uniform - their structure varies dramatically from ground to sky. It remains unknown whether these non-uniformities are reflected in the large-scale organization of the early visual system and what benefits such adaptations would confer. Here, by relying on the efficient coding hypothesis, we predict that changes in the structure of receptive fields across visual space increase the efficiency of sensory coding. We show experimentally that, in agreement with our predictions, receptive fields of retinal ganglion cells change their shape along the dorsoventral retinal axis, with a marked surround asymmetry at the visual horizon. Our work demonstrates that, according to principles of efficient coding, the panoramic structure of natural scenes is exploited by the retina across space and cell-types.

neuroscience↗

bioRxiv2021

Cortical efficient coding dynamics shape behavioral performance.

Neurons throughout the sensory pathway adapt their responses depending on the statistical structure of the sensory environment. Contrast gain control is a form of adaptation in the auditory cortex, but it is unclear whether the dynamics of gain control reflect efficient adaptation, and whether they shape behavioral perception. Here, we trained mice to detect a target presented in background noise shortly after a change in the contrast of the background. The observed changes in cortical gain and behavioral detection followed the dynamics of a normative model of efficient contrast gain control; specifically, target detection and sensitivity improved slowly in low contrast, but degraded rapidly in high contrast. Auditory cortex was required for this task, and cortical responses were not only similarly affected by contrast but predicted variability in behavioral performance. Combined, our results demonstrate that dynamic gain adaptation supports efficient coding in auditory cortex and predicts the perception of sounds in noise.

neuroscience↗

bioRxiv2019

Statistical analysis and optimality of biological systems

Normative theories and statistical inference provide complementary approaches for the study of biological systems. A normative theory postulates that organisms have adapted to efficiently solve essential tasks, and proceeds to mathematically work out testable consequences of such optimality; parameters that maximize the hypothesized organismal function can be derived ab initio, without reference to experimental data. In contrast, statistical inference focuses on efficient utilization of data to learn model parameters, without reference to any a priori notion of biological function, utility, or fitness. Traditionally, these two approaches were developed independently and applied separately. Here we unify them in a coherent Bayesian framework that embeds a normative theory into a family of maximum-entropy "optimization priors." This family defines a smooth interpolation between a data-rich inference regime (characteristic of "bottom-up" statistical models), and a data-limited ab inito prediction regime (characteristic of "top-down" normative theory). We demonstrate the applicability of our framework using data from the visual cortex, the retina, and C. elegans, and argue that the flexibility it affords is essential to address a number of fundamental challenges relating to inference and prediction in complex, high-dimensional biological problems.

neuroscience↗

bioRxiv2019

Adaptability and efficiency in neural coding

The ability to adapt to changes in stimulus statistics is a hallmark of sensory systems. Here, we develop a theoretical framework that can account for the dynamics of adaptation from an information-processing perspective. We use this framework to optimize and analyze adaptive sensory codes, and we show that codes optimized for stationary environments can suffer from prolonged periods of poor performance when the environment changes. To mitigate the adversarial effects of these environmental changes, sensory systems must navigate tradeoffs between the ability to accurately encode incoming stimuli, and the ability to rapidly detect and adapt to changes in the distribution of these stimuli. We derive families of codes that balance these objectives, and we demonstrate their close match to experimentally-observed neural dynamics during mean and variance adaptation. Our results provide a unifying perspective on adaptation across a range of sensory systems, environments, and sensory tasks.

neuroscience↗

bioRxiv2019

Ecological origins of perceptual grouping principles in the auditory system

Events and objects in the world must be inferred from sensory signals to support behavior. Because sensory measurements are temporally and spatially local, the estimation of an object or event can be viewed as the grouping of these measurements into representations of their common causes. Per-ceptual grouping is believed to reflect internalized regularities of the natural environment, yet grouping cues have traditionally been identified using informal observation, and investigated using artificial stim-uli. The relationship of grouping to natural signal statistics has thus remained unclear, and additional or alternative cues remain possible. Here we derive auditory grouping cues by measuring and summarizing statistics of natural sound features. Feature co-occurrence statistics reproduced established cues but also revealed previously unappreciated grouping principles. The results suggest that auditory grouping is adapted to natural stimulus statistics, show how these statistics can reveal novel grouping phenomena, and provide a framework for studying grouping in natural signals.

neuroscience↗

bioRxiv2018

Defective DNA damage repair leads to frequent catastrophic genomic events in murine and human tumors

Chromothripsis and chromoanasynthesis are catastrophic events leading to clustered genomic rearrangements. Whole-genome sequencing revealed frequent chromothripsis or chromoanasynthesis (n= 16/26) in brain tumors developing in mice deficient for factors involved in homologous-recombination-repair or non-homologous-end-joining. Catastrophic events were tightly linked to Myc/Mycn amplification, with increased DNA damage and inefficient apoptotic response already observable at early postnatal stages. Inhibition of repair processes and comparison of the mouse tumors with human medulloblastomas (n=68) and glioblastomas (n=32) identified chromothripsis as associated with MYC/MYCN gains and with DNA repair deficiencies, pointing towards therapeutic opportunities to target DNA repair defects in tumors with complex genomic rearrangements.

cancer biology↗

bioRxiv2017

Adaptive coding for dynamic sensory inference

Behavior relies on the ability of sensory systems to infer properties of the environment from incoming stimuli. The accuracy of inference depends on the fidelity with which behaviorally-relevant properties of stimuli are encoded in neural responses. High-fidelity encodings can be metabolically costly, but low-fidelity encodings can cause errors in inference. Here, we discuss general principles that underlie the tradeoff between encoding cost and inference error. We then derive adaptive encoding schemes that dynamically navigate this tradeoff. These optimal encodings tend to increase the fidelity of the neural representation following a change in the stimulus distribution, and reduce fidelity for stimuli that originate from a known distribution. We predict dynamical signatures of such encoding schemes and demonstrate how known phenomena, such as burst coding and firing rate adaptation, can be understood as hallmarks of optimal coding for accurate inference.

neuroscience↗