Combinatorial Effects of Alpha- and Gamma-Protocadherins on Neuronal Survival and Dendritic Self-Avoidance.

The clustered protocadherins (Pcdhs) comprise 58 cadherin-related proteins encoded by three tandemly arrayed gene clusters, Pcdh-α, Pcdh-ß, and Pcdh-γ (Pcdha, Pcdhb, and Pcdhg, respectively). Pcdh isoforms from different clusters are combinatorially expressed in neurons. They form multimers that interact homophilically and mediate a variety of developmental processes, including neuronal survival, synaptic maintenance, axonal tiling, and dendritic self-avoidance. Most studies have analyzed clusters individually. Here, we assessed functional interactions between Pcdha and Pcdhg clusters. To circumvent neonatal lethality associated with deletion of Pcdhgs, we used Crispr-Cas9 genome editing in mice to combine a constitutive Pcdha mutant allele with a conditional Pcdhg allele. We analyzed roles of Pcdhas and Pcdhgs in the retina and cerebellum from mice (both sexes) lacking one or both clusters. In retina, Pcdhgs are essential for survival of inner retinal neurons and dendritic self-avoidance of starburst amacrine cells, whereas Pcdhas are dispensable for both processes. Deletion of both Pcdha and Pcdhg clusters led to far more dramatic defects in survival and self-avoidance than Pcdhg deletion alone. Comparisons of an allelic series of mutants support the conclusion that Pcdhas and Pcdhgs function together in a dose-dependent and cell-type-specific manner to provide a critical threshold of Pcdh activity. In the cerebellum, Pcdhas and Pcdhgs also cooperate to mediate self-avoidance of Purkinje cell dendrites, with modest but significant defects in either single mutant and dramatic defects in the double mutant. Together, our results demonstrate complex patterns of redundancy between Pcdh clusters and the importance of Pcdh cluster diversity in postnatal CNS development.SIGNIFICANCE STATEMENT The formation of neural circuits requires diversification and combinatorial actions of cell surface proteins. Prominent among them are the clustered protocadherins (Pcdhs), a family of ∼60 neuronal recognition molecules. Pcdhs are encoded by three closely linked gene clusters called Pcdh-α, Pcdh-ß, and Pcdh-γ. The Pcdhs mediate a variety of developmental processes, including neuronal survival, synaptic maintenance, and spatial patterning of axons and dendrites. Most studies to date have been limited to single clusters. Here, we used genome editing to assess interactions between Pcdh-α and Pcdh-γ gene clusters. We examined two regions of the CNS, the retina and cerebellum and show that the 14 α-Pcdhs and 22 γ-Pcdhs act synergistically to mediate neuronal survival and dendrite patterning.

Stress echocardiography for left ventricular diastolic dysfunction detection in patients with non-severe chronic obstructive pulmonary disease: a cross-sectional study.

AIM: To assess whether the simultaneous performance of exercise stress echocardiography and cardio-pulmonary testing (ESE-CPET) may facilitate the timely diagnosis of subclinical left ventricular diastolic dysfunction (LVDD) in patients with non-severe chronic obstructive pulmonary disease (COPD), preserved left ventricular systolic function, and exertional dyspnea or exercise intolerance. METHODS: This cross-sectional study, conducted between May 2017 and April 2018, involved 104 non-severe COPD patients with exertional dyspnea and preserved ejection fraction who underwent echocardiography before CPET and 1-2 minutes after peak exercise. Based on the peak E/e' ratio, patients were divided into the group with stress-induced LVDD - E/e'>15 and the group without stress-induced LVDD. We assessed the association between LVDD and the following CPET variables: minute ventilation, peak oxygen uptake (VO2), ventilatory efficiency, heart rate reserve, and blood pressure. RESULTS: During ESE-CPET, stress-induced LVDD occurred in 67/104 patients (64%). These patients had lower work load, peak VO2, O2 pulse, and minute ventilation (VE), and higher VE/VCO2 slope than patients without stress-induced LVDD (35.18±10.4 vs 37.01±11.11, P<0.05). None of the CPET variables correlated with E/e'. CONCLUSION: Combined ESE-CPET may distinguish masked LVDD in patients with non-severe COPD with exertional dyspnea and preserved left ventricular systolic function. None of the CPET variables was a predictor for subclinical LVDD.

Protocadherins mediate dendritic self-avoidance in the mammalian nervous system.

Dendritic arborizations of many neurons are patterned by a process called self-avoidance, in which branches arising from a single neuron repel each other. By minimizing gaps and overlaps within the arborization, self-avoidance facilitates complete coverage of a neuron's territory by its neurites. Remarkably, some neurons that display self-avoidance interact freely with other neurons of the same subtype, implying that they discriminate self from non-self. Here we demonstrate roles for the clustered protocadherins (Pcdhs) in dendritic self-avoidance and self/non-self discrimination. The Pcdh locus encodes 58 related cadherin-like transmembrane proteins, at least some of which exhibit isoform-specific homophilic adhesion in heterologous cells and are expressed stochastically and combinatorially in single neurons. Deletion of all 22 Pcdh genes in the mouse γ-subcluster (Pcdhg genes) disrupts self-avoidance of dendrites in retinal starburst amacrine cells (SACs) and cerebellar Purkinje cells. Further genetic analysis of SACs showed that Pcdhg proteins act cell-autonomously during development, and that replacement of the 22 Pcdhg proteins with a single isoform restores self-avoidance. Moreover, expression of the same single isoform in all SACs decreases interactions among dendrites of neighbouring SACs (heteroneuronal interactions). These results suggest that homophilic Pcdhg interactions between sibling neurites (isoneuronal interactions) generate a repulsive signal that leads to self-avoidance. In this model, heteroneuronal interactions are normally permitted because dendrites seldom encounter a matched set of Pcdhg proteins unless they emanate from the same soma. In many respects, our results mirror those reported for Dscam1 (Down syndrome cell adhesion molecule) in Drosophila: this complex gene encodes thousands of recognition molecules that exhibit stochastic expression and isoform-specific interactions, and mediate both self-avoidance and self/non-self discrimination. Thus, although insect Dscam and vertebrate Pcdh proteins share no sequence homology, they seem to underlie similar strategies for endowing neurons with distinct molecular identities and patterning their arborizations.

Biomarkers in COPD - Challenging, Real or Illusive.

Biomarker research in COPD is becoming the most rapidly progressing sphere in respiratory medicine. Although "omics" generate a huge amount of biomarkers, fibrinogen is the only one validated by the European Medicines Agency. Thousands of studies analyzing different biological samples from the respiratory tract, collected in different ways, using various kits and techniques are generating more and more data, rendering biomarkers very confusing rather than having practical value. It seems that in order to be applicable and validated, biomarkers should be analysed in an accurately described cohort of patients, homogeneous in disease severity and activity. As COPD has multiple mechanisms of pathobiology it raises the issue of which is the most appropriate biological sample reflecting each of them. Unified criteria for tissue sampling, validated kits for respiratory tract probes and standardized technologies should be announced. The review presents the biomarkers that are currently validated and raises the problem of standardization.

ALK Mutation Status in EGFR-negative Non-small-cell Lung Cancer Patients in Bulgaria.

BACKGROUND: Patients with non-small-cell lung cancer (NSCLC) with anaplastic lymphoma kinase (ALK) rearrangement mutation are found to be 3-13%. AIM: To evaluate the prevalence of ALK mutations in EGFR-negative NSCLC patients in Bulgaria. MATERIALS AND METHODS: One hundred and thirty-two patients with EGFR-negative NSCLC were examined for ALK mutation analysis between January and June 2016. Data were obtained from patients' register of four major oncological hospitals in Bulgaria. RESULTS: Data were available for 124 (93.9%) patients, tumor mass was insufficient for analysis in 8 (6.1%) patients. Most of the patients were with adenocarcinoma (82 patients, 62.1%); 11 patients (8.3%) were with squamous histology and 2 patients (1.5%) were with other type of NSCLC. Histology data were missing in 37 patients (28.0%). ALK mutation was confirmed in 5 patients (3.8%), 119 (90.2%) patients had ALK wild type. ALK positive patients were with adenocarcinoma (n=3), squamous cell carcinoma (n=1) and other type (n=1) NSCLC. All ALK mutations were observed in never smokers (n=3) and former smokers (n=2). CONCLUSION: The present study is the first of this kind in Bulgaria - it investigates the prevalence of ALK mutation rate in EGFR-negative NSCLC patients, which was found to be 3.8%. The presence of EGFR, ALK or other driver mutations is a prerequisite for targeted therapy and thus needs to be accurately assessed in NSCLC.

Chronic Obstructive Pulmonary Disease and Hepatitis C.

Chronic obstructive pulmonary disease (COPD) is a preventable, treatable disease with significant extrapulmonary manifestations that could affect negatively its course in some patients. Hepatitis C virus infection (HCV), on the other hand, is associated with a number of extrahepatic manifestations. COPD patients have increased prevalence of HCV and patients with HCV, especially older ones, have increased prevalence and faster progression of COPD. HCV infection exerts long-term effects on lung tissue and is an additional risk factor for the development of COPD. The presence of HCV is associated with an accelerated loss of lung function in COPD patients, especially in current smokers. COPD could represent extrahepatic manifestation associated with HCV infection. The aim of this article was to review the literature on prevalence of HCV in COPD and vice versa, pathogenetic link and the consequences of their mutual existence.

Diabetes Mellitus Type 2 in Hospitalized COPD Patients: Impact on Quality of Life and Lung Function.

INTRODUCTION: Diabetes mellitus (DM) is estimated to affect 2-37% of COPD patients, results varying widely between studies. DM may also correlate with quality of life and lung function. AIM: To examine correlations between DM and quality of life and lung function in COPD patients admitted to hospital with exacerbation of COPD. PATIENTS AND METHODS: A hundred and fifty-two patients were included in the study. They were all examined for diabetes mellitus. All patients completed CAT and mMRC questionnaires and underwent spirometry. RESULTS: 13.2% (20/152) of patients received medications for DM. 21.7% (33/152) had newly diagnosed DM and 30.9% (47/152) had prediabetes. DM is not associated with reduced quality of life and worse pulmonary function. However, untreated DM is associated with both reduced quality of life and worse pulmonary function. HbA1c is negatively correlated with FVC and positively correlated with CAT score. CONCLUSIONS: COPD patients hospitalized for exacerbation are at high risk for impaired glucose metabolism. Untreated DM is associated with worse lung function and lower quality of life, which stresses the importance of screening for the disease. The patients may benefit from optimizing blood glucose level.

Therapeutic approaches to the treatment of recurrent respiratory papillomatosis of the aerodigestive tract (a clinical study).

Recurrent respiratory papillomatosis (RRP) is a rare disease, characterized by recurrent proliferation of benign squamous cell papillomas in the larynx as well as in the other parts of the aerodigestive tract. We have compared different treatment options for RRP of the aerodigestive tract including surgical, conservative and combined approaches. A total of 43 patients with papillomatosis that received a combined therapy were followed in the period from 2009 to 2013. The treatment included electrosurgery and CO2 laser surgery alongside with either immunotherapy with Bacillus Calmette-Guerin (BCG) (Calgevax) or α-interferon. In the control group without immunotherapy (n = 16) we used conventional microlaryngeal surgery. During the follow-up, relapse occurred in two patients for the CO2 laser surgery with Calgevax immunotherapy group (n = 16). In the group treated with α-interferon preceded by CO2 laser surgery (n = 9) and electrosurgery (n = 2), relapse had occurred in three patients. Among the control group, recurrence was observed in six patients. This required re-operation. Our data showed a three times more frequent relapses among patients who were operated with conventional surgery as compared to those operated with CO2 laser surgery and Calgevax immunotherapy, and two times more often relapses in patients operated with conventional surgery as compared to those with electrosurgery and CO2 laser surgery and application of α-interferon therapy. Conventional and laser surgeries have a palliative effect, though playing an important role in ensuring the airway patency. While specific antivirus treatment for human papilloma viruses does not exist, the immune modulation with Calgevax considerably reduces the frequency of relapses, by stimulating cellular immune effector mechanisms. The combined protocol allows rarefication of relapses and improvement of patients' quality of life, but not complete healing.

A deep-learning strategy to identify cell types across species from high-density extracellular recordings.

High-density probes allow electrophysiological recordings from many neurons simultaneously across entire brain circuits but don't reveal cell type. Here, we develop a strategy to identify cell types from extracellular recordings in awake animals, revealing the computational roles of neurons with distinct functional, molecular, and anatomical properties. We combine optogenetic activation and pharmacology using the cerebellum as a testbed to generate a curated ground-truth library of electrophysiological properties for Purkinje cells, molecular layer interneurons, Golgi cells, and mossy fibers. We train a semi-supervised deep-learning classifier that predicts cell types with greater than 95% accuracy based on waveform, discharge statistics, and layer of the recorded neuron. The classifier's predictions agree with expert classification on recordings using different probes, in different laboratories, from functionally distinct cerebellar regions, and across animal species. Our classifier extends the power of modern dynamical systems analyses by revealing the unique contributions of simultaneously-recorded cell types during behavior.

Visualization of the individual blood microbiome to study the etiology of sarcoidosis.

Introduction: Single microbial pathogens or host-microbiome dysbiosis are the causes of lung diseases with suspected infectious etiology. Metagenome sequencing provides an overview of the microbiome content. Due to the rarity of most granulomatous lung diseases collecting large systematic datasets is challenging. Thus, single-patient data often can only be summarized visually. Objective: To increase the information gain from a single-case metagenome analysis we suggest a quantitative and qualitative approach. Results: The 16S metagenomic results of 7 patients with pulmonary sarcoidosis were compared with those of 22 healthy individuals. From lysed blood, total microbial DNA was extracted and sequenced. Cleaned data reads were identified taxonomically using Kraken 2 software. Individual metagenomic data were visualized with a Sankey diagram, Krona chart, and a heat-map. We identified five genera that were exclusively present or significantly enhanced in patients with sarcoidosis - Veillonella, Prevotella, Cutibacterium, Corynebacterium, and Streptococcus. Conclusions: Our approach can characterize the blood microbiome composition and diversity in rare diseases at an individual level. Investigation of the blood microbiome in patients with granulomatous lung diseases of unknown etiology, such as sarcoidosis could enhance our comprehension of their origin and pathogenesis and potentially uncover novel personalized therapeutics.

Reward signals in the cerebellum: Origins, targets, and functional implications.

The cerebellum has long been proposed to play a role in cognitive function, although this has remained controversial. This idea has received renewed support with the recent discovery that signals associated with reward can be observed in the cerebellar circuitry, particularly in goal-directed learning tasks involving an interplay between the cerebellar cortex, basal ganglia, and cerebral cortex. Remarkably, a wide range of reward contingencies-including reward expectation, delivery, size, and omission-can be encoded by specific circuit elements in a manner that reflects the microzonal organization of the cerebellar cortex. The facts that reward signals have been observed in both the mossy fiber and climbing fiber input pathways to the cerebellar cortex and that their convergence may trigger plasticity in Purkinje cells suggest that these interactions may be crucial for the role of the cerebellar cortex in learned behavior. These findings strengthen the emerging consensus that the cerebellum plays a pivotal role in shaping cognitive processing and suggest that the cerebellum may combine both supervised learning and reinforcement learning to optimize goal-directed action. We make specific predictions about how cerebellar circuits can work in concert with the basal ganglia to guide different stages of learning.

Tuberculosis in Adolescents in Bulgaria for a Three-Year Period: 2018-2020.

Background: Each year, approximately two million adolescents and young adults in the world become infected with tuberculosis (TB). The problem is that the classification of the disease includes children in the age group 0−14 years and young adults aged 15 and over. The present study aims to analyze and compare the epidemiology and clinical presentation of TB in Bulgaria in the different age subgroups of childhood. Methods: A retrospective study was undertaken of the newly diagnosed children (n = 80) with TB treated onsite from January 2018 to December 2020 at the Multiprofile Hospital for Active Treatment of Pulmonary Diseases ("St. Sofia"). They were distributed into three age groups: aged 8−11 (prepuberty), aged 12−14 (younger adolescents), and aged above 15 (older adolescents). Results: A clear finding of the research indicated that adolescent children develop TB both as primary and secondary infections. In a large number of cases with the children under our care, we found enlarged intrathoracic lymph nodes as well as infiltrative changes in the lungs, i.e., we observed transitional forms. There were statistically significant differences between the age group >15 years old and each of the other two younger groups for diagnosis, the severity of intoxication, and BK spreading status. Conclusion: The course of tuberculosis in adolescence has its own specifics and differences between the three age groups in the current study.

MiRNA expression profiling in adenocarcinoma and squamous cell lung carcinoma reveals both common and specific deregulated microRNAs.

The current study investigated the expression signatures of miRNAs in lung adenocarcinoma (LUAD) and squamous cell lung carcinoma (LUSC). miRNA profiling was performed using microarray in 12 LUAD and 12 LUSC samples and adjacent normal tissues. In LUAD, 107 miRNAs were significantly deregulated, whereas 235 miRNAs were deregulated in LUSC. Twenty-six miRNAs were common between the 2 cancer subtypes and 8 were prioritized for validation, in addition to 6 subtype-specific miRNAs. The RT-qPCR validation samples included 50 LUAD, 50 LUSC, and adjacent normal tissues. Eight miRNAs were validated in LUAD: 3 upregulated - miR-7-5p, miR-375-5p, miR-6785-3p, and 5 downregulated - miR-101-3p, miR-139-5p, miR-140-3p, miR-144-3p, miR-195-5p. Ten miRNAs were validated in the LUSC group: 3 upregulated - miR-7-5p, miR-21-3p, miR-650, and 7 downregulated - miR-95-5p, miR-140-3p, miR-144-3p, miR-195-5p, miR-375, miR-744-3p, and miR-4689-3p. Reactome pathway analysis revealed that the target genes of the deregulated miRNAs in LUAD were significantly enriched in cell cycle, membrane trafficking, gene expression processes, and EGFR signaling, while in LUSC, they were enriched in the immune system, transcriptional regulation by TP53, and FGFR signaling. This study identified distinct miRNA profiles in LUSC and LUAD, which are common and specific miRNAs that could be further investigated as biomarkers for diagnosis and prognosis.

EGFR mutation status yield from bronchoalveolar lavage in patients with primary pulmonary adenocarcinoma compared to a venous blood sample and tissue biopsy.

BACKGROUND: In recent years, there has been a revolution in the genomic profiling and molecular typing of lung cancer. A key oncogene is the epidermal growth factor receptor (EGFR). The gold standard for determining EGFR mutation status is tissue biopsy, where a histological specimen is taken by a bronchoscopic or surgical method (transbronchial biopsy, forceps biopsy, etc.). However, in clinical practice the tissue sample is often insufficient for morphological and molecular analysis. Bronchoalveolar lavage is a validated diagnostic method for pathogenic infections in the lower respiratory tract, yet its diagnostic value for oncogenic mutation testing in lung cancer has not been extensively investigated. This study aims to compare the prevalence of EGFR mutation status in bronchoalveolar lavage and peripheral blood referring to the gold standard - tissue biopsy in patients with primary lung adenocarcinoma. METHODS: Twenty-six patients with adenocarcinoma were examined for EGFR mutation from tissue biopsy, peripheral blood sample and bronchoalveolar lavage. RESULTS: Thirteen patients had wild type EGFR and the other 13 had EGFR mutation. EGFR mutation from a peripheral blood sample was identified in 38.5% (5/13) of patients, whereas EGFR mutation obtained from bronchoalveolar lavage (BAL) was identified in 92.3% (12/13). This study demonstrates that a liquid biopsy sample for EGFR status from BAL has a higher sensitivity compared to a venous blood sample.

A Case of Tracheal Stenosis as an Isolated Form of Immunoproliferative Hyper-IgG4 Disease in a 17-Year-Old Girl.

Immunoglobulin G4-related disease (IgG4-RD) is a lymphoproliferative disease which is described almost exclusively in adults. There are only a few pediatric patients who have been observed with this disorder. Here, we describe a rare case of IgG4-RD in a 17-year-old girl with a single manifestation-tracheal stenosis without previous intubation or other inciting event. She had mixed dyspnea and noisy and weakened breathing. Immunoproliferative hyper-IgG4 disease was diagnosed, based on elevated serum IgG4 and histological findings. Until now we have chosen to treat the girl only with corticosteroids with a good response so far. The general condition as well as the respiratory function are regularly monitored. The tracheal involvement of IgG4-RD is uncommon. Nonetheless, it is a manifestation that should be included in the differential diagnosis of tracheal stenosis.

Neuropixels 2.0: A miniaturized high-density probe for stable, long-term brain recordings.

Measuring the dynamics of neural processing across time scales requires following the spiking of thousands of individual neurons over milliseconds and months. To address this need, we introduce the Neuropixels 2.0 probe together with newly designed analysis algorithms. The probe has more than 5000 sites and is miniaturized to facilitate chronic implants in small mammals and recording during unrestrained behavior. High-quality recordings over long time scales were reliably obtained in mice and rats in six laboratories. Improved site density and arrangement combined with newly created data processing methods enable automatic post hoc correction for brain movements, allowing recording from the same neurons for more than 2 months. These probes and algorithms enable stable recordings from thousands of sites during free behavior, even in small animals such as mice.

Endobronchial Ultrasound Transbronchial Needle Aspiration for the Diagnosis of Paratracheal and Peribronchial Central Parenchymal Lesions.

OBJECTIVES: Obtaining qualitative, sufficient material for the diagnosis of malignancies in cases with normal endoscopic findings in patients with suspected lung cancer and hilar and mediastinal lymphadenopathy is challenging. MATERIALS AND METHODS: Endobronchial ultrasound (EBUS) was used to control a transbronchial needle biopsy (ТBNA) for the first time in our country. From 2015 to 2018, TBNA with a convex probe EBUS was performed on 57 patients [41 men, 16 women, mean age 56.10 (range 37-77 years)] with mediastinal lesions found on CT scan. We used the Hitachi Aloka - ProSound Alpha 7 and BF-UC180F (Olympus) 21G and 22G needles Ultrasound System. In 22 of the cases, we performed a biopsy of hilum lesions (9 on the left and 13 on the right), in 13 - of subcarinal lesions, and in 4 - of lesions located on the right paratracheal lymphatic chain. RESULTS: EBUS-TBNA confirmed lung cancer in 48 patients (84.2%). In 33 of them, it was non-small cell lung cancer: spinocellular in 13 cases and adenocarcinoma in 17 cases; three cases were without accurate verification. Small cell lung cancer was found in 15 cases. In two cases, the biopsies were negative for tumor (3.5%), and in seven - non-specific inflammatory process (12.3%). CONCLUSIONS: This study confirms the high diagnostic success rate of EBUS-TBNA reported in similar studies developed on a daily routine basis without adhering to a specific protocol. EBUS-TBNA is an interventional procedure with high sensitivity in diagnosing hilar and mediastinal lesions in negative conventional bronchoscopy and thus is useful in patients with paratracheal and peribronchial lesions. The results could be improved with training and experience.

Publisher Correction: Predictive and reactive reward signals conveyed by climbing fiber inputs to cerebellar Purkinje cells.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Epigenetic Targets for Therapeutic Approaches in COPD and Asthma. Nutrigenomics ­ Possible or Illusive.

Oxidative stress generated by cigarette smoking, environmental pollution, or other noxious particles leads to epigenetic changes in the cells of the respiratory tract. They reflect cell adaptation in response to chronic exposure to external factors. Although there is no change in the genetic code, epigenetic changes may be heritable and translated from one generation to another, accumulating abnormalities and rendering cells into entirely different phenotype, causing disease. DNA methylation, post-translation histone modification, ubiquitination, sumoylation and miRNA transcriptional regulation are the major processes that are responsible for the epigenetic control of gene expression. All of them are reversible. They can be regulated by targeting specific enzymes/proteins involved in the process in order to mitigate inflammation. Chronic respiratory diseases have epigenetic signatures that affect gene expression in the lung. Targeting them provides the development of novel diagnostic and therapeutic approaches in respiratory medicine. Nutrigenomics reveals the beneficial effect of natural phytochemicals, affecting key steps in the signaling pathways of chronic respiratory diseases.

Predictive and reactive reward signals conveyed by climbing fiber inputs to cerebellar Purkinje cells.

There is increasing evidence for a cerebellar contribution to cognitive processing, but the specific input pathways conveying this information remain unclear. We probed the role of climbing fiber inputs to Purkinje cells in generating and evaluating predictions about associations between motor actions, sensory stimuli and reward. We trained mice to perform a visuomotor integration task to receive a reward and interleaved cued and random rewards between task trials. Using two-photon calcium imaging and Neuropixels probe recordings of Purkinje cell activity, we show that climbing fibers signal reward expectation, delivery and omission. These signals map onto cerebellar microzones, with reward delivery activating some microzones and suppressing others, and with reward omission activating both reward-activated and reward-suppressed microzones. Moreover, responses to predictable rewards are progressively suppressed during learning. Our findings elucidate a specific input pathway for cerebellar contributions to reward signaling and provide a mechanistic link between cerebellar activity and the creation and evaluation of predictions.