S100B protein, astrocytes and memory

S100 is a vertebrate-specific family of small, calcium-binding proteins. One of them is the S100B protein, mostly expressed in, and released by astroglial cells in the brain. The protein has been implicated in the regulation of numerous processes including phosphorylation of cytoskeletal proteins, cell proliferation and differentiation, as well as many other functions. This article focuses on the role of S100B in processes relating to learning and memory. More than four decades of behavioral and neurophysiological research have revealed beneficial effects of this protein. However, there is also evidence suggesting that overexpression of S100B can lead to memory dysfunction. It is possible that an increased S100B release from astrocytes may be co-responsible for memory dysfunction observed in the early stages of Alzheimer's disease

Relationship between neurological and cerebellar soft signs, and implicit motor learning in schizophrenia and bipolar disorder

Background: Schizophrenia (SZ) and bipolar disorder (BD) patients share deficits in motor functions in the form of neurological (NSS) and cerebellar soft signs (CSS), and implicit motor learning disturbances. Here, we use cluster analysis method to assess (1) the relationship between those abnormalities in SZ and BD and (2) the differences between those groups. Methods: 33 SZ patients, 33 BD patients as well as 31 healthy controls (HC) took part in the study. We assessed CSS with the International Cooperative Ataxia Rating Scale (ICARS) and NSS with the Neurological Evaluation Scale (NES). Implicit motor learning was evaluated with the Serial Reaction Time Task (SRTT). Participants were divided into clusters (Ward's method) based on the mean response time and mean error rate in SRTT. The difference in ICARS and NES scores, and SRTT variables between clusters were evaluated. We have measured associations between SRTT parameters and both ICARS and NES total scores and subscores. Results: Cluster analysis based on the SRTT parameters allowed to extract three clusters. Those were characterized by the increasing disruption of motor functioning (psychomotor retardation, the severity of NSS and CSS) regardless of the diagnosis. Cluster 1 covered almost all of HC and was characterized by faster reaction times and small number of errors. BD and SZ patients represented in cluster 1, although fully functional in performing the SRTT, showed higher rates of NSS and CSS. Patients with BD and SZ were set apart in clusters 2 and 3 in a similar proportion. Cluster 2 presented significantly slower reaction times but with the comparable number of errors to cluster 1. Cluster 3 consisted of participants with normal or decreased reaction time and significantly increased number of errors. None of the clusters were predominantly composed of the patients representing one psychiatric diagnosis. Conclusions: To our best knowledge, we are presenting the first data indicating the relationship between implicit motor learning and NSS and CSS in SZ and BD patients' groups. Lack of clusters predominantly represented by patients with the diagnosis of SZ or BD may refer to the model of schizophrenia-bipolar disorder boundary, pointing out the similarities between those two disorders

Vergence eye movements in bipolar disorder

Aim. With respect to bipolar disorder (BD), previous research have demonstrated saccadic eye movements abnormalities, manifested mainly as an increase in reaction time (latency) in both prosaccadic and antisaccadic task. So far, there were no studies related to vergence eye movements in subjects with BD. Our primary aim was to evaluate vergence tracking performance in this clinical group.  Methods. 30 patients with BD in remission and 23 healthy controls were enrolled. Subjects underwent optometric examination where near point of convergence was measured by the use of Wolff Wand. Instrumented convergence measurements were performed using infrared eye tracker and dedicated vergence stimuli generator. Results. BD patients presented significantly higher average error between eyes’ convergence and convergence required to fixate the target and higher number of saccadic intrusions compared with healthy controls group. Principal component analysis performed on oculometric parameters revealed differences between BD patients and healthy controls. Significant correlations between the vergence disturbances and saccadic intrusions were found. Conclusions. BD patients showed the alterations of the vergence eye movements similar to the disturbances of eye movements in the fronto-parallel plane. While the abnormalities of vergence eye movements in some mental disorders have been reported, we have for the first time objectively measured this phenomenon in BD

Miocene land snails from Belchatów (Central Poland). II: Aciculidae (Gastropoda Prosobranchia)

The paper reports five species of Aciculidae from calcareous intercalations within lignite units of the opencast brown coal mine in Belchatów. Two of them, Acicula schlickumi (Schütt 1967) and Renea pretiosa (Andreae 1904) were only poorly known on the basis of some incomplete shells, while Acicula crassistoma is described as a new species