Fast-Spiking Interneurons of the Premotor Cortex Contribute to Initiation and Execution of Spontaneous Actions.

Planning and execution of voluntary movement depend on the contribution of distinct classes of neurons in primary motor and premotor areas. However, timing and pattern of activation of GABAergic cells during specific motor behaviors remain only partly understood. Here, we directly compared the response properties of putative pyramidal neurons (PNs) and GABAergic fast-spiking neurons (FSNs) during spontaneous licking and forelimb movements in male mice. Recordings centered on the face/mouth motor field of the anterolateral motor cortex (ALM) revealed that FSNs fire longer than PNs and earlier for licking, but not for forelimb movements. Computational analysis revealed that FSNs carry vastly more information than PNs about the onset of movement. While PNs differently modulate their discharge during distinct motor acts, most FSNs respond with a stereotyped increase in firing rate. Accordingly, the informational redundancy was greater among FSNs than PNs. Finally, optogenetic silencing of a subset of FSNs reduced spontaneous licking movement. These data suggest that a global rise of inhibition contributes to the initiation and execution of spontaneous motor actions.SIGNIFICANCE STATEMENT Our study contributes to clarifying the causal role of fast-spiking neurons (FSNs) in driving initiation and execution of specific, spontaneous movements. Within the face/mouth motor field of mice premotor cortex, FSNs fire before pyramidal neurons (PNs) with a specific activation pattern: they reach their peak of activity earlier than PNs during the initiation of licking, but not of forelimb, movements; duration of FSNs activity is also greater and exhibits less selectivity for the movement type, as compared with that of PNs. Accordingly, FSNs appear to carry more redundant information than PNs. Optogenetic silencing of FSNs reduced spontaneous licking movement, suggesting that FSNs contribute to the initiation and execution of specific spontaneous movements, possibly by sculpting response selectivity of nearby PNs.

Preclinical upper limb neurorobotic platform to assess, rehabilitate, and develop therapies.

Numerous neurorehabilitative, neuroprosthetic, and repair interventions aim to address the consequences of upper limb impairments after neurological disorders. Although these therapies target widely different mechanisms, they share the common need for a preclinical platform that supports the development, assessment, and understanding of the therapy. Here, we introduce a neurorobotic platform for rats that meets these requirements. A four-degree-of-freedom end effector is interfaced with the rat's wrist, enabling unassisted to fully assisted execution of natural reaching and retrieval movements covering the entire body workspace. Multimodal recording capabilities permit precise quantification of upper limb movement recovery after spinal cord injury (SCI), which allowed us to uncover adaptations in corticospinal tract neuron dynamics underlying this recovery. Personalized movement assistance supported early neurorehabilitation that improved recovery after SCI. Last, the platform provided a well-controlled and practical environment to develop an implantable spinal cord neuroprosthesis that improved upper limb function after SCI.

Combining Optogenetic Stimulation and Motor Training Improves Functional Recovery and Perilesional Cortical Activity.

Background. An ischemic stroke is followed by the remapping of motor representation and extensive changes in cortical excitability involving both hemispheres. Although stimulation of the ipsilesional motor cortex, especially when paired with motor training, facilitates plasticity and functional restoration, the remapping of motor representation of the single and combined treatments is largely unexplored. Objective. We investigated if spatio-temporal features of motor-related cortical activity and the new motor representations are related to the rehabilitative treatment or if they can be specifically associated to functional recovery. Methods. We designed a novel rehabilitative treatment that combines neuro-plasticizing intervention with motor training. In detail, optogenetic stimulation of peri-infarct excitatory neurons expressing Channelrhodopsin 2 was associated with daily motor training on a robotic device. The effectiveness of the combined therapy was compared with spontaneous recovery and with the single treatments (ie optogenetic stimulation or motor training). Results. We found that the extension and localization of the new motor representations are specific to the treatment, where most treatments promote segregation of the motor representation to the peri-infarct region. Interestingly, only the combined therapy promotes both the recovery of forelimb functionality and the rescue of spatio-temporal features of motor-related activity. Functional recovery results from a new excitatory/inhibitory balance between hemispheres as revealed by the augmented motor response flanked by the increased expression of parvalbumin positive neurons in the peri-infarct area. Conclusions. Our findings highlight that functional recovery and restoration of motor-related neuronal activity are not necessarily coupled during post-stroke recovery. Indeed the reestablishment of cortical activation features of calcium transient is distinctive of the most effective therapeutic approach, the combined therapy.

Experimental and Computational Study on Motor Control and Recovery After Stroke: Toward a Constructive Loop Between Experimental and Virtual Embodied Neuroscience.

Being able to replicate real experiments with computational simulations is a unique opportunity to refine and validate models with experimental data and redesign the experiments based on simulations. However, since it is technically demanding to model all components of an experiment, traditional approaches to modeling reduce the experimental setups as much as possible. In this study, our goal is to replicate all the relevant features of an experiment on motor control and motor rehabilitation after stroke. To this aim, we propose an approach that allows continuous integration of new experimental data into a computational modeling framework. First, results show that we could reproduce experimental object displacement with high accuracy via the simulated embodiment in the virtual world by feeding a spinal cord model with experimental registration of the cortical activity. Second, by using computational models of multiple granularities, our preliminary results show the possibility of simulating several features of the brain after stroke, from the local alteration in neuronal activity to long-range connectivity remodeling. Finally, strategies are proposed to merge the two pipelines. We further suggest that additional models could be integrated into the framework thanks to the versatility of the proposed approach, thus allowing many researchers to achieve continuously improved experimental design.

A Robotic System for Adaptive Training and Function Assessment of Forelimb Retraction in Mice.

Rodent models are decisive for translational research in healthy and pathological conditions of motor function thanks to specific similarities with humans. Here, we present an upgraded version of the M-Platform, a robotic device previously designed to train mice during forelimb retraction tasks. This new version significantly extends its possibilities for murine experiments during motor tasks: 1) an actuation system for friction adjustment allows to automatically adapt pulling difficulty; 2) the device can be used both for training, with a retraction task, and for assessment, with an isometric task; and 3) the platform can be integrated with a neurophysiology systems to record simultaneous cortical neural activity. Results of the validation experiments with healthy mice confirmed that the M-Platform permits precise adjustments of friction during the task, thus allowing to change its difficulty and that these variations induce a different improvement in motor performance, after specific training sessions. Moreover, simultaneous and high quality (high signal-to-noise ratio) neural signals can be recorded from the rostral forelimb area (RFA) during task execution. With the novel features presented herein, the M-Platform may allow to investigate the outcome of a customized motor rehabilitation protocol after neural injury, to analyze task-related signals from brain regions interested by neuroplastic events and to perform optogenetic silencing or stimulation during experiments in transgenic mice.

FarmaREL: An Italian pharmacovigilance project to monitor and evaluate adverse drug reactions in haematologic patients.

Adverse drug reactions (ADRs) reduce patients' quality of life, increase mortality and morbidity, and have a negative economic impact on healthcare systems. Nevertheless, the importance of ADR reporting is often underestimated. The project "FarmaREL" has been developed to monitor and evaluate ADRs in haematological patients and to increase pharmacovigilance culture among haematology specialists. In 13 haematology units, based in Lombardy, Italy, a dedicated specialist with the task of encouraging ADRs reporting and sensitizing healthcare professionals to pharmacovigilance has been assigned. The ADRs occurring in haematological patients were collected electronically and then analysed with multiple logistic regression. Between January 2009 and December 2011, 887 reports were collected. The number of ADRs was higher in older adults (528; 59%), in male (490; 55%), and in non-Hodgkin lymphoma patients (343; 39%). Most reactions were severe (45% required or prolonged hospitalization), but in most cases, they were fully resolved at the time of reporting. According to Schumock and Thornton criteria, a percentage of ADRs as high as 7% was found to be preventable versus 2% according to reporter opinion. Patients' haematological diagnosis, not age or gender, resulted to be the variable that most influenced ADR, in particular severity and outcome. The employment of personnel specifically dedicated to pharmacovigilance is a successful strategy to improve the number and quality of ADR reports. "FarmaREL", the first programme of active pharmacovigilance in oncohaematologic patients, significantly contributed to reach the WHO "Gold Standard" for pharmacovigilance in Lombardy, Italy.

Adefovir added to lamivudine for hepatitis B recurrent infection in refractory B-cell chronic lymphocytic leukemia on prolonged therapy with Campath-1H.

We describe a case of severe reactivation of occult hepatitis B virus infection in a 49-year-old man, who was treated with high doses of chlorambucil for a Binet stage A B-cell chronic lymphocytic leukemia (B-CLL). The patient was initially treated with lamivudine and subsequently with lamivudine and adefovir dipivoxil combination therapy to control viral replication and allow for long-term anti-cancer chemotherapy with alemtuzumab (Campath-1H), which was introduced to rescue for a B-CLL relapse. During 20 months of anti-HBV therapy, ALT and HBV-DNA levels progressively declined and B-CLL was successfully kept under control by long-term alemtuzumab administration.

ZAP-70 immunoreactivity is a prognostic marker of disease progression in chronic lymphocytic leukemia.

The expression of zeta-associated protein 70 (ZAP-70) in chronic lymphocytic leukemia (CLL) seems to correlate with the mutational status of the immunoglobulin heavy-chain variable-region genes, clinical course and patient prognosis. The aim was to determine the prognostic significance of the immunohistochemical expression of ZAP-70 protein in CLL by means of the long-term follow-up of 108 patients. This study identified 3 patterns of ZAP-70 immunoreactivity: negative (58 patients, 54%), weakly positive (20 patients, 18%) and strongly positive (30 patients, 28%). Overall, ZAP-70 immunoreactivity correlated with an abnormal karyotype ( p = 0.017), a lymphocyte doubling time (LDT) of <6 months ( p = 0.001) and <12 months ( p = 0.01), Rai II - IV and Binet B - C stage ( p = 0.013), the clinical need for chemotherapy ( p < 0.001) and the need for more than 1 chemotherapy line ( p < 0.001). Kaplan-Meier analysis demonstrated that ZAP-70 immunoreactivity closely correlated with a shorter LDT ( p < 0.0001) and time from diagnosis to initial therapy ( p = 0.0001). The same significance was retained when the patients were stratified into the ZAP-70 immunoreactivity groups ( p < 0.0001). This study shows that ZAP-70 immunoreactivity can be a reliable prognostic marker in CLL and proposes a system for evaluating the results. The observations support the inclusion of the immunohistochemical expression of ZAP-70 in clinical trials involving CLL patients.

A pilot study of low-dose subcutaneous alemtuzumab therapy for patients with hemotherapy-refractory chronic lymphocytic leukemia.

Subcutaneous low-dose alemtuzumab (10 mg t.i.w. for 18 weeks) induced a 50% response rate, including 25% complete response, in 16 patients with refractory chronic lymphocytic leukemia (CLL) patients. The responses were substantial even in patients with unfavorable cytogenetics, fludarabine/rituximab refractoriness, Rai stage IV, previous infections, and age over 65 years. Subcutaneous low-dose alemtuzumab is effective in poor prognosis B-CLL, and has a particularly favourable toxicity profile.