Homeostatic Modulation of Stimulation-Dependent Plasticity in Human Motor Cortex

Since recently, it is possible, using noninvasive cortical stimulation, such as the protocol of paired associative stimulation (PAS), to induce the plastic changes in the motor cortex, in humans that mimic Hebb's model of learning. Application of TMS conjugated with peripheral electrical stimulation at strictly coherent temporal manner lead to convergence of inputs in the sensory-motor cortex, with the consequent synaptic potentiation or weakening, if applied repetitively. However, when optimal interstimulus interval (ISI) for induction of LTP-like effects is applied as a single pair, Motor evoked potential (MEP) amplitude inhibition is observed, the paradigm known as short-latency afferent inhibition (SLAI). Aiming to resolve this paradox, PAS protocols were applied, with 200 repetitions of TMS pulses paired with median nerve electrical stimulation, at ISI equal to individual latencies of evoked response of somatosensory cortex (N-20) (PASLTP), and at ISI of N-20 shortened for 5 msec (PASLTD) protocols that mimic LTP-like changes in the human motor cortex. MEP amplitudes before, during and after interventions were measured as an indicator based on output signals originating from the motor system. Post-intervention MEP amplitudes following the TMS protocols of PASLTP and PASLTD were facilitated and depressed, respectively, contrary to MEP amplitudes during intervention. During PASLTP MEP amplitudes were significantly decreased in case of PASLTP, while in the case of PASLTD an upward trend was observed. In conclusions, a possible explanation for the seemingly paradoxical effect of PAS can be found in the mechanism of homeostatic modulation of plasticity. Those findings indicate the existence of complex relationships in the development of plasticity induced by stimulation, depending on the level of the previous motor cortex excitability

Veterinarski informacioni menadžment sistem (VIMS) u procesu prijavljivanja i menadžmenta zaraznih bolesti

A prerequisite to the development of an efficient animal health, food safety and traceability management system in the animal food production chain is the implementation of an integrated veterinary informational management system (VIMS) capable for the capture, storage, analysis and retrieval of data and providing the opportunity for the cumulative gathering of the knowledge and capability for its competent interpretation. Such a system will enable collecting appropriate data, including quality management and inspection controls, from all establishments and commodities in the 'from farm to fork' food production chain (farms, holdings, slaughterhouses, laboratories, traders etc.) in a structured, predefined format, and facilitate competent analyses and reporting of such data, as well as the improvement of the existing programs and strategies. The role of information system in animal disease diagnosis, surveillance and notification, control of national and international trade of commodities, food safety management, investigation of diseases, predictive microbiology and quantitative risk assessment is of great importance for the quality of veterinary service. Integral part of the VIMS is animal disease notification system designed according to and in compliance with international requirements, standards and recommendation and able to exchange relevant information with similar information systems. The aim of this contribution is to describe national animal disease notification system which is in place in Serbia as a part of VIMS.Preduslov za uspostavljanje efikasnog sistema menadžmenta zdravstvene zaštite životinja, bezbednosti hrane i sledljivosti u lancu proizvodnje hrane je uvođenje integrisanog veterinarskog informacionog menadžment sistema (VIMS) razvijenog na takav način da omogući prikupljanje, čuvanje, analizu i povlačenje podataka i obezbedi kumulativno skupljanje saznanja i njihovu stručnu interpretaciju. Takav sistem će omogućiti prikupljanje podataka, uključujući one iz upravljanja kvalitetom i u okviru inspekcijskih kontrola, od svih objekata u sistemu proizvodnje hrane 'od farme do viljuške' (farme, gazdinstva, klanice, laboratorije, lica koja se bave prometom i dr.) u strukturirano, unapred definisanom obliku, i obezbediti kompetentnu analizu takvih podataka kao i unapređenje postojećih programa i strategija. Uloga informacionih sistema u dijagnostici, nadzoru i prijavljivanju zaraznih bolesti, kontroli unutrašnjeg i međunarodnog prometa, upravljanju bezbednošću hrane, istraživanju žarišta zaraznih bolesti, prediktivnoj mikrobiologiji i kvantitativnoj analizi rizika je od izuzetnog značaja za kvalitet veterinarske službe. Sastavni deo VIMS-a je sistem za prijavljivanje zaraznih bolesti dizajniran prema i u saglasnosti sa međunarodnim zahtevima, standardima i preporukama i osposobljen da vrši razmenu određenih podatka sa sličnim informacionim sistemima. Cilj ovog rada je da se opiše nacionalni sistem za prijavljivanje zaraznih bolesti koji je u Srbiji u primeni kao deo VIMS-a

Complex modulation of fingertip forces during precision grasp and lift after theta burst stimulation over the dorsal premotor cortex

Background/Aim. Adaptive control and fingertip force synchronization of precise grasp stability during unimanual manipulation of small objects represents an illustrative example of highly fractionated movements that are foundation of fine motor control. It is assumed that this process is controlled by several motor areas of the frontal lobe, particularly applicable to the primary motor (M-1) and dorsal premotor cortex (PMd). Aiming to examine the role of PMd during fine coordination of fingertip forces we applied theta burst repetitive magnetic stimulation (TBS) to disrupt neural processing in that cortical area. Methods. Using a single-blind, randomized, crossover design, 10 healthy subjects (29 ± 3.9 years) received single sessions of continuous TBS (cTBS600), intermittent TBS (iTBS600), or sham stimulation, separate from one another at least one week, over the PMd region of dominant hemisphere. Precision grasp and lift were assessed by instrumented device, recording grip (G) and load (L) forces, during three manipulation tasks (ramp-and-hold, oscillation force producing and simple lifting tasks), with each hand separately, before and after interventions. Results. We observed the improvement of task performance related to constant error (CE) in oscillation task with the dominant hand (DH) after the iTBS (p = 0.009). On the contrary, the cTBS reduced variable error (VE) for non-dominant hand (NH), p = 0.005. Considering force coordination we found that iTBS worsened variables for NH (G/L ratio, p = 0.017; cross-correlation of the G and L, p = 0.047; Gain, p = 0.047). Conclusion. These results demonstrate the ability of TBS to modulate fingertip forces during precision grasping and lifting, when applied over PMd. These findings support the role of PMd in human motor control and forces generation required to hold small objects stable in our hands

History of exposure to dopaminergic medication does not affect motor cortex plasticity and excitability in Parkinson's disease

Objective: Little is known whether and how chronic exposure to dopaminergic treatment alters physiological mechanisms in Parkinson's disease (PD). Methods: Two clinically similar groups of PD patients, one consisting of drug-naive patients and another of patients already on chronic dopaminergic medication (when off medication), were compared to each other and to a control group. Plasticity and excitability of the hand primary motor cortex of the more affected side were evaluated using transcranial magnetic stimulation (TMS) techniques. Results: There was little difference between two patient groups, and both groups showed similar differences in comparison to controls: decreased facilitatory sensory-motor plasticity (as measured by paired associative stimulation [PAS] protocol), impaired short-interval intracortical inhibition (SICI), and diminished slope of input-output curves at higher TMS intensities. The exception was that 30 min after PAS, intracortical facilitation (ICF) was significantly reduced in drug-naive patients, whereas it changed much less in other two groups. Conclusions: Chronic exposure to dopaminergic drugs does not affect substantially the features of motor cortex excitability and plasticity in PD. There is little interaction between plasticity and excitability features of motor cortex in PD. Significance: Reduced response to facilitatory PAS protocol, reduced SICI, and reduced slope of the input-output curve at higher TMS pulse intensities, seem to be physiological markers for the presence of the pathological disease process in PD. Long term treatment does not seem to change the underlying physiology of the disease

Sport-Specific Warm-Up Attenuates Static Stretching-Induced Negative Effects on Vertical Jump But Not Neuromuscular Excitability in Basketball Players

The purpose of this study was to examine the acute effects of static stretching (SS) and dynamic stretching (DS), alone and in combination with specific basketball warm-up (SBWU), on the neuromuscular excitability and vertical jump height in basketball players. Twelve healthy young male basketball players participated in the study (18 +/- 0.42 years; 17.4 - 18.6 age range; 188 +/- 9 cm; 76.5 +/- 9 kg). All participants completed two different stretching treatments (static and dynamic), performed on different days at least seven days apart, in the same period of training microcycle, in a counterbalanced order. Each session consisted of a self-paced jogging warm-up, followed by a 10-minute testing period (T0), which involved eliciting H reflex and M waves, followed by three trials of a vertical jump test. Participants then performed one of the treatment protocols. After another test (T1), participants conducted 8-minute specific basketball warm-up and then one more test (T2). Combined 3 (time) x 2 (stretching protocol) analysis of variance with repeated measures on both factors revealed that SS significantly decreased spinal excitability (H/M ratio) (p = 0.015, d = -0.38, percentage of change = -20.55%) and vertical jump height (p = 0.007, d = -1.91, percentage of change = -2.6%), but after SBWU, vertical jump height increased (p = 0.006, d = 1.13, percentage of change = 3.01%), while H/M ratio continued decreasing (p = 0.019, d = -0.45, percentage of change = -30.23%). Acute effects of DS, alone and in combination with SBWU were not significant. It seems that SBWU attenuates negative acute effects of SS on vertical jump performance in young basketball players, while DS appears to cause no significant acute effect for this population