Two brains in action: joint-action coding in the primate frontal cortex

Daily life often requires the coordination of our actions with those of another partner. After sixty years (1968-2018) of behavioral neurophysiology of motor control, the neural mechanisms which allow such coordination in primates are unknown. We studied this issue by recording cell activity simultaneously from dorsal premotor cortex (PMd) of two male interacting monkeys trained to coordinate their hand forces to achieve a common goal. We found a population of 'joint-action cells' that discharged preferentially when monkeys cooperated in the task. This modulation was predictive in nature, since in most cells neural activity led in time the changes of the "own" and of the "other" behavior. These neurons encoded the joint-performance more accurately than 'canonical action-related cells', activated by the action per se, regardless of the individual vs. interactive context. A decoding of joint-action was obtained by combining the two brains activities, using cells with directional properties distinguished from those associated to the 'solo' behaviors. Action observation-related activity studied when one monkey observed the consequences of the partner's behavior, i.e. the cursor's motion on the screen, did not sharpen the accuracy of 'joint-action cells' representation, suggesting that it plays no major role in encoding joint-action. When monkeys performed with a non-interactive partner, such as a computer, 'joint-action cells' representation of the "other" (non-cooperative) behavior was significantly degraded. These findings provide evidence of how premotor neurons integrate the time-varying representation of the self-action with that of a co-actor, thus offering a neural substrate for successful visuo-motor coordination between individuals.SIGNIFICANT STATEMENTThe neural bases of inter-subject motor coordination were studied by recording cell activity simultaneously from the frontal cortex of two interacting monkeys, trained to coordinate their hand forces to achieve a common goal. We found a new class of cells, preferentially active when the monkeys cooperated, rather than when the same action was performed individually. These 'joint-action neurons' offered a neural representation of joint-behaviors by far more accurate than that provided by the canonical action-related cells, modulated by the action per se regardless of the individual/interactive context. A neural representation of joint-performance was obtained by combining the activity recorded from the two brains. Our findings offer the first evidence concerning neural mechanisms subtending interactive visuo-motor coordination between co-acting agents

Superficial peroneal nerve entrapment in ankle sprain in childhood and adolescence

Traumatic injuries of the ankle are the most common injuries in sports. Up to 40% of patients who have undergone inversion ankle sprain report residual symptoms. The primary purpose of the study is to evaluate the incidence of SPN entrapment as consequence of acute severe inversion ankle sprain in children and adolescents; the secondary is to report the diagnostic pathway and the results after surgical treatment. From 2000 to 2015 were reviewed to summarize patients under the age of 15 years treated for a first episode of severe inversion ankle sprain. Cases with persistent symptoms (more than 3 months) indicative for SPN neuropathy were then identified. Instrumental investigations were recovered and a pre-operative assessment of pain (VAS) was recorded. Patients were evaluated at minimum of 1-year post-operative follow-up. 981 acute ankle sprains have been evaluated. 122 were considered severe according to van Dijk criteria. 5 patients were considered affected by neuropathy of the SPN. All patients underwent surgery consisting in neurolysis and capsular retention and ligament reconstruction. At 25 months of follow-up AOFAS moved from 57.6 to 98.6. The study highlights a previously unreported condition of perineural fibrosis of the superficial peroneal nerve at the level of the ankle following first acute severe inversion ankle sprain in children

Aesthetic Alteration of Marble Surfaces Caused by Biofilm Formation: Effects of Chemical Cleaning

Despite the massive presence of biofilms causing aesthetic alteration to the facade of the Monza Cathedral, our team in a previous work proved that the biocolonization was not a primary damaging factor if compared to chemical-physical deterioration due to the impact of air pollution. Nonetheless, the conservators tried to remove the sessile dwelling microorganisms to reduce discolouration. In this research, two nearby sculpted leaves made of Candoglia marble were selected to study the effects of a chemical treatment combining the biocides benzalkonium chloride, hydrogen peroxide and Algophase\uae and mechanical cleaning procedures. One leaf was cleaned with the biocides and mechanically, and the other was left untreated as control. The impact of the treatment was investigated after 1 month from the cleaning by digital microscopy, environmental scanning electron microscopy, confocal microscopy and molecular methods to determine the composition and the functional profiles of the bacterial communities. Despite the acceptable aesthetic results obtained, the overall cleaning treatment was only partially effective in removing the biofilm from the colonized surfaces and, therefore, not adequately suitable for the specific substrate. Furthermore, the cleaning process selected microorganisms potentially more resistant to biocides so that the efficacy of future re-treatment by antimicrobial agents could be negatively affected

Multidrug-resistant Pseudomonas aeruginosa producing PER-1 extended-spectrum serine-beta-lactamase and VIM-2 metallo-beta-lactamase.

[No abstract available]Europena Training and Mobility of Researchers Network on Metallo-beta-Lactamases (grant no. FMRX-CT98-0232