I know what I will see: action-specific motor preparation activity in a passive observation task

Literature on mirror neurons has shown that seeing someone preparing to move generates in the motor areas of the observers a brain activity similar to that generated when the subject prepares his own actions. Thus, the ‘mirroring’ of action would not be limited to the execution phase but also involves the preparation process. Here we confirm and extend this notion showing that, just as different brain activities prepare different voluntary actions, also different brain activities prepare to observe different predictable actions. Videos of two different actions from egocentric point of view were presented in separate blocks: (i) grasping of a cup and (ii) impossible grasping of a cup. Subjects had to passively observe the videos showing object-directed hand movements. Through the use of the event-related potentials, we found a cortical activity before observing the actions, which was very similar to the one recorded prior to the actual execution of that same action, in terms of both topography and latency. This anticipatory activity does not represent a general preparation state but an action-specific state, because being dependent on the specific meaning of the forthcoming action. These results reinforce our knowledge about the correspondence between action, perception and cognition.     

Rapid Response to Cyclosporin A and Favorable Renal Outcome in Nongenetic Versus Genetic Steroid–Resistant Nephrotic Syndrome

Background and objectives

Treatment of congenital nephrotic syndrome (CNS) and steroid–resistant nephrotic syndrome (SRNS) is demanding, and renal prognosis is poor. Numerous causative gene mutations have been identified in SRNS that affect the renal podocyte. In the era of high–throughput sequencing techniques, patients with nongenetic SRNS frequently escape the scientific interest. We here present the long-term data of the German CNS/SRNS Follow-Up Study, focusing on the response to cyclosporin A (CsA) in patients with nongenetic versus genetic disease.

Design, setting, participants, & measurements

Cross–sectional and longitudinal clinical data were collected from 231 patients with CNS/SRNS treated at eight university pediatric nephrology units with a median observation time of 113 months (interquartile range, 50–178). Genotyping was performed systematically in all patients.

Results

The overall mutation detection rate was high at 57% (97% in CNS and 41% in SRNS); 85% of all mutations were identified by the analysis of three single genes only (NPHS1, NPHS2, and WT1), accounting for 92% of all mutations in patients with CNS and 79% of all mutations in patients with SRNS. Remission of the disease in nongenetic SRNS was observed in 78% of patients after a median treatment period of 2.5 months; 82% of nongenetic patients responded within 6 months of therapy, and 98% of patients with nongenetic SRNS and CsA–induced complete remission (normalbuminemia and no proteinuria) maintained a normal renal function. Genetic SRNS, on the contrary, is associated with a high rate of ESRD in 66% of patients. Only 3% of patients with genetic SRNS experienced a complete remission and 16% of patients with genetic SRNS experienced a partial remission after CsA therapy.

Conclusions

The efficacy of CsA is high in nonhereditary SRNS, with an excellent prognosis of renal function in the large majority of patients. CsA should be given for a minimum period of 6 months in these patients with nongenetic SRNS. In genetic SRNS, response to CsA was low and restricted to exceptional patients.     

Different neural capacity limitations for articulatory and non-articulatory maintenance of verbal information

Many studies have demonstrated attenuated verbal working memory (WM) under articulatory suppression. However, performance is not completely abolished, suggesting a less efficient, non-articulatory mechanism for the maintenance of verbal information. The neural causes for the reduced efficiency of such a putative complementary maintenance system have not yet been addressed. The present study was conducted to fill this gap. Subjects performed a Sternberg task (a) under articulatory maintenance at low, high, and supracapacity set sizes and (b) under non-articulatory maintenance at low and high set sizes. With functional magnetic resonance imaging, set-size related increases in activity were compared between subvocal articulatory rehearsal and non-articulatory maintenance. First, the results replicate previous findings showing different networks underlying these two maintenance strategies. Second, activation of all key nodes of the articulatory maintenance network increased with the amount of memorized information, showing no plateau at high set sizes. In contrast, for non-articulatory maintenance, there was evidence for a plateau at high set sizes in all relevant areas of the network. Third, for articulatory maintenance, the non-articulatory maintenance network was additionally recruited at supracapacity set sizes, presumably to assist processing in this highly demanding condition. This is the first demonstration of differential neural bottlenecks for articulatory and non-articulatory maintenance. This study adds to our understanding of the performance differences between these two strategies supporting verbal WM.     

Both plasmacytoid dendritic cells and monocytes stimulate natural killer cells early during human herpes simplex virus type 1 infections

Herpes simplex virus type 1 (HSV‐1), a member of the herpes virus family, is characterized by a short replication cycle, high cytopathogenicity and distinct neurotropism. Primary infection and reactivation may cause severe diseases in immunocompetent and immunosuppressed individuals. This study investigated the role of human plasmacytoid dendritic cells (pDC) in the activation of natural killer (NK) cells for the control of herpesviral infections. Within peripheral blood mononuclear cells, UV‐inactivated HSV‐1 and CpG‐A induced CD69 up‐regulation on NK cells, whereas infectious HSV‐1 was particularly active in inducing NK cell effector functions interferon‐γ (IFN‐γ) secretion and degranulation. The pDC‐derived IFN‐α significantly contributed to NK cell activation, as evident from neutralization and cell depletion experiments. In addition, monocyte‐derived tumour necrosis factor‐α (TNF‐α) induced after exposure to infectious HSV‐1 was found to stimulate IFN‐γ secretion. A minority of monocytes was shown to be non‐productively infected in experiments using fluorescently labelled viruses and quantitative PCR analyses. HSV‐1‐exposed monocytes up‐regulated classical HLA‐ABC and non‐classical HLA‐E molecules at the cell surface in an IFN‐α‐dependent manner, whereas stress molecules MICA/B were not induced. Notably, depletion of monocytes reduced NK cell effector functions induced by infectious HSV‐1 (P < 0·05). Altogether, our data suggest a model in which HSV‐1‐stimulated pDC and monocytes activate NK cells via secretion of IFN‐α and TNF‐α. In addition, infection of monocytes induces NK cell effector functions via TNF‐α‐dependent and TNF‐α‐independent mechanisms. Hence, pDC and monocytes, which are among the first cells infiltrating herpetic lesions, appear to have important bystander functions for NK cells to control these viral infections.