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It is plausible to hypothesize that the spiking responses of certain neurons represent functions of the spiking signals of other neurons. A natural ensuing question concerns how to use experimental data to infer what kind of a function is being computed. Model-based approaches typically require assumptions on how information is represented. By contrast, information measures are sensitive only to relative behavior: information is unchanged by applying arbitrary invertible transformations to the involved random variables. This paper develops an approach based on the information bottleneck method that attempts to find such functional relationships in a neuron population. Specifically, the information bottleneck method is used to provide appropriate compact representations which can then be parsed to infer functional relationships. In the present paper, the parsing step is specialized to the case of remapped-linear functions. The approach is validated on artificial data and then applied to recordings from the motor cortex of a macaque monkey performing an arm-reaching task. Functional relationships are identified and shown to exhibit some degree of persistence across multiple trials of the same experiment.

Background: Forced vital capacity (FVC) and six-minute walk distance (6MWD) are robust markers in interstitial lung diseases (ILD) to assess severity and prognosis. It is unknown whether high-resolution computed tomography pattern has any independent effect on the exercise capacity in ILD. We compared six-minute walk test (6MWT) parameters between usual interstitial pneumonia (UIP) and non-UIP ILD after adjusting for FVC. Methods: Data from a tertiary care ILD clinic were retrospectively analysed. Based on HRCT, patients were classified as UIP and non-UIP. 6MWT parameters and FVC were recorded for enrolled patients. 6MWD, distance-saturation product (DSP) and exertional desaturation were compared between UIP and non-UIP, using analysis of covariance (ANCOVA), with per cent predicted FVC as covariate. Patients were grouped as mild (≥70%), moderate (51%–69%) and severe (≤50%) based on FVC severity. Results: Out of 169 patients enrolled, only patients with all three data points: spirometry, 6MWT and HRCT were included in the analysis (n = 139). UIP group comprised 56 (40.3%), while non-UIP group had 83 (59.7%) patients. More females and lesser smokers were present in non-UIP group. Mean predicted FVC% was similar between the two HRCT groups (P = 0.611) and had a statistically significant, though very weak to weak correlation with 6MWT parameters {6MWD (r = 0.138); pred 6MWD% (r = 0.170); desaturation (r = -0.227); DSP index (r = 0.166)}. Analysis of covariance showed no statistically significant difference in the 6MWT parameters between UIP and non-UIP groups for similar FVC levels. Conclusion: For a similar level of lung function, exercise capacity was similar for patients with UIP and non-UIP pattern ILD.

Blau syndrome is a rare condition characterized by the triad of granulomatous skin lesions, symmetric polyarthritis with boggy joint swellings, and ocular inflammation. It has an autosomal dominant mode of inheritance and occurs due to a mutation in CARD-15/NOD-2 gene which encodes the cytosolic NOD2 protein, a key molecule in the regulation of innate immunity. Clinical onset is generally in the 1st year of life and is characterized by articular, cutaneous, and ocular noncaseating granulomatous inflammation, which can be variably associated with a heterogeneous systemic spectrum. Here, we describe one such rare case.

Background: Systemic sclerosis (SSc) is a rare multisystemic autoimmune disorder in which the esophagus is the second most common organ to be affected after the skin, leading to dysmotility. Literature available on esophageal dysmotility in SSc is limited. Moreover, studies explaining the spectrum of esophageal dysmotility in the disease in the Indian population are sparse. Aim: The aim of this study was to characterize esophageal motility disorders in SSc using esophageal high-resolution manometry (HRM) in a representative of the Southwestern Indian population. Methods: Thirty-two SSc patients participated in the study. All of them met the inclusion and exclusion criteria and underwent esophageal HRM at the Gastrointestinal Physiology Laboratory, Department of Physiology, of our center. The findings were interpreted using the Chicago Classification v3.0 criteria. Results: Among patients of SSc with a mean age of 42.25 ± 10.45 years, 19 (59.38%) had “absent contractility (AC),” 3 (9.38%) had “ineffective esophageal motility (IEM),” 3 (9.38%) had “type I achalasia, 1 (3.13%) had “esophagogastric junction outflow obstruction,” and 6 (18.75%) had “normal” HRM findings. The HRM parameter of “basal lower esophageal sphincter pressure” differed significantly between “IEM type I achalasia” (P = 0.043) and “type I achalasia AC” groups (P = 0.032), while “median integral relaxation pressure” of “type I achalasia” groups showed significant difference with “normal, IEM, and AC” groups each (P < 0.001). Conclusions: The findings of the study suggest that varying degrees of esophageal motility disorders are present in SSc using HRM as defined by the Chicago Classification v3.0. Majority (59.38%) of patients had AC, but the rest of them showed other dysmotility patterns.