Local field potentials in a pre-motor region predict learned vocal sequences

Neuronal activity within the premotor region HVC is tightly synchronized to, and crucial for, the articulate production of learned song in birds. Characterizations of this neural activity detail patterns of sequential bursting in small, carefully identified subsets of neurons in the HVC population. The dynamics of HVC are well described by these characterizations, but have not been verified beyond this scale of measurement. There is a rich history of using local field potentials (LFP) to extract information about behavior that extends beyond the contribution of individual cells. These signals have the advantage of being stable over longer periods of time, and they have been used to study and decode human speech and other complex motor behaviors. Here we characterize LFP signals presumptively from the HVC of freely behaving male zebra finches during song production to determine if population activity may yield similar insights into the mechanisms underlying complex motor-vocal behavior. Following an initial observation that structured changes in the LFP were distinct to all vocalizations during song, we show that it is possible to extract time-varying features from multiple frequency bands to decode the identity of specific vocalization elements (syllables) and to predict their temporal onsets within the motif. This demonstrates the utility of LFP for studying vocal behavior in songbirds. Surprisingly, the time frequency structure of HVC LFP is qualitatively similar to well-established oscillations found in both human and non-human mammalian motor areas. This physiological similarity, despite distinct anatomical structures, may give insight into common computational principles for learning and/or generating complex motor-vocal behaviors.

A wireless spinal stimulation system for ventral activation of the rat cervical spinal cord

Electrical stimulation of the cervical spinal cord is gaining traction as a therapy following spinal cord injury; however, it is difficult to target the cervical motor region in a rodent using a non-penetrating stimulus compared with direct placement of intraspinal wire electrodes. Penetrating wire electrodes have been explored in rodent and pig models and, while they have proven beneficial in the injured spinal cord, the negative aspects of spinal parenchymal penetration (e.g., gliosis, neural tissue damage, and obdurate inflammation) are of concern when considering therapeutic potential. We therefore designed a novel approach for epidural stimulation of the rat spinal cord using a wireless stimulation system and ventral electrode array. Our approach allowed for preservation of mobility following surgery and was suitable for long term stimulation strategies in awake, freely functioning animals. Further, electrophysiology mapping of the ventral spinal cord revealed the ventral approach was suitable to target muscle groups of the rat forelimb and, at a single electrode lead position, different stimulation protocols could be applied to achieve unique activation patterns of the muscles of the forelimb.

Comparative characteristic of capillaries 5 layers of motor region of the person and rat brain ischemia

Aim – to reveal existence pf similarities and differences in reaction of capillaries of the 5th layer motor bark at experimental ischemia of at white brain rats and the relevant department of a brain of the person at chronic insufficiency blood supplies because of atherosclerotic damage of brain arteries. Material and methods: on 36 medicines of a brain of white rats at which the model of ischemia of body by bandaging of the left general sleepy was created arteries and 36 – from corpses of 55-90 years suffering from atherosclerotic damage of the arteries feeding a brain with reduction of diameter by 75-85% are studied by histologic techniques a condition of the capillary course of the 5th layer of bark of a motor zone of hemispheres. Results of a research and discussion: similar and not comparable distinction of changes of the microcirculation course of the fifth layer of bark of a motor zone are revealed and rats and the person in the conditions of brain ischemia. It is established that the capillary course at white rats, unlike the person, is steadier against ischemia. Conclusion. Results of the conducted research confirm a hypothesis of the progressing defeat of the microcirculation course of motor bark on to measure of reduction of diameter of brain arteries at the person, demand a certain care at extrapolation of results experiments to clinic.

Evolutionary divergence of locomotion in two related vertebrate species

Locomotion exists in diverse forms in nature and is adapted to the environmental constraints of each species1. However, little is known about how closely related species with similar neuronal circuitry can evolve different navigational strategies to explore their environments. We established a powerful approach in comparative neuroethology to investigate evolution of neuronal circuits in vertebrates by comparing divergent swimming pattern of two closely related larval fish species, Danionella translucida (DT) and Danio rerio or zebrafish (ZF)2,3. During swimming, we demonstrate that DT utilizes lower half tail-beat frequency and amplitude to generate a slower and continuous swimming pattern when compared to the burst-and-glide swimming pattern in ZF. We found a high degree of conservation in the brain anatomy between the two species. However, we revealed that the activity of a higher motor region, referred here as the Mesencephalic Locomotion Maintenance Neurons (MLMN) correlates with the duration of swim events and differs strikingly between DT and ZF. Using holographic stimulation, we show that the activation of the MLMN is sufficient to increase the frequency and duration of swim events in ZF. Moreover, we propose two characteristics, availability of dissolved oxygen and timing of swim bladder inflation, which drive the observed differences in the swim pattern. Our findings uncover the neuronal circuit substrate underlying the evolutionary divergence of navigational strategies and how they are adapted to their respective environmental constraints.

Effects of tDCS Dose and Electrode Montage on regional cerebral blood flow and motor behavior

We used three dose levels (Sham, 2mA and 4mA) and two different electrode montages (unihemispheric or bihemispheric) to examine DOSE and MONTAGE effects on regional cerebral blood flow (rCBF) as a surrogate marker of neural activity, and on a finger sequence task, as a surrogate behavioral measure drawing on brain regions targeted by transcranial direct current stimulation (tDCS). We placed the anodal electrode over the right motor region (C4) while the cathodal or return electrode was placed either over a left supraorbital region (unihemispheric montage) or over the left motor region (C3 in the bihemispheric montage). Performance changes in the finger sequence task for both hands (left hand: p = 0.0026, and right hand: p = 0.0002) showed a linear tDCS dose response, but no effect of montage. rCBF in the the right hemispheric perirolandic area increased with dose under the anodal electrode (p = 0.027), while in the perirolandic ROI in the left hemisphere, rCBF showed a trend to increase with dose (p = 0.053), and significant effect of montage (p = 0.00004). The bihemispheric montage showed additional rCBF increases in frontomesial regions in the 4mA condition but not in the 2mA condition. Furthermore, we found correlations between rCBF changes in the right perirolandic region and improvements in the finger sequence task performance (FSP) for left and right hand. Our data support not only a strong direct tDCS dose effect for rCBF and FSP as surrogate measures of targeted brain regions, but also indirect effects on rCBF in functionally connected regions (e.g., frontomesial regions), particularly in the higher dose condition, and on FSP of the ipsilateral hand (to the anodal electrode). At higher dose and irrespective of polarity, a wider network of sensorimotor regions is positively affected by tDCS.Graphical AbstractHighlightstDCS-DOSE had linear effect on finger sequence performance for both handsrCBF changes in both perirolandic ROIs demonstrated tDCS-DOSE effects and left perirolandic ROI demonstrated tDCS-MONTAGE effects.Simulated current intensity in the left and right perirolandic ROI strongly correlated with the contralateral hand’s finger sequence performance.tDCS-Tolerability scores did not correlate with change in rCBF or finger sequence performance of the left hand.

Edouard Long. The central pathways of general sensitivity (anatomo-clinical study). Paris. 1899

In the first part of his work, the author gives a literary survey of the question of the central conductors of general sensitivity. The order of presentation is as follows: sensitive pathways of the spinal cord, brain stem, large brain (from thalamus opticus to the cortex); at the end, the author examines the arguments in favor of one or another localization of the sensory motor region in the cortex.

About the feeling function of the so-called the motor region of the human cerebral cortex

How known is the question of whether we have only motor centers in the region of the central convolutions, or together with the feeling and feeling centers, hence, the so-called. sense-motor centers, still remains not completely clarified.

Isometric Exercising Impact on Dynamics of Physical Condition Indicators of Dorsopathy Patients

Introduction. the low-back pain is a challenging medical issue. the disorder polymorphism requires ongoing search for new treatment solutions based on up-to-date technologies, including these related to rehabilitation and preventive treatment of pathological conditions. However, our findings have shown, most studies are narrowly focused on one or several pathogenesis components only. the dedicated publications do not fully highlight the role, which the basic physical characteristics (BPC) have in building movement patterns. Purpose of the study. Our research was aimed at working out an isometric exercising program for dorsopathy patients to develop the above characteristics. Material and research methods. We analyzed findings of the clinical and functional examination methods as well as treatment results of 150 patients. the design included the pre-randomization into treatment and control groups, clinical study techniques, questionnaire-based surveys, use of genuine FSSD diagnostic profile and tension dynamometry to assess both initial BPC values and their dynamics at the adjustment stage. Results. According to the further result analysis, within the treatment group of patients suffering from pain-associated dorsopahies, the proposed exercising program allowed the add-on of BPC like tone, strength and endurance of main posture- dependent muscle groups as to static and dynamic loads. At that, comparing to the control group, where patients exercised to mobilize a vertebral motor region and have general restorative effect, no positive impact on the indicators was acquired. Conclusion. The study proved the deviation of dorsopathy patients’ BPC from the age-appropriate norms. In addition, complex functional assessment of spine and myofascial system was described based on functional muscle testing and movement tasks.

Plasticity of the Primary Motor Cortex in Patients with Primary Brain Tumors

There are two neuron-level mechanisms proposed to underlie neural plasticity: recruiting neurons nearby to support the lost function (ipsilesional plasticity) and uncovering latent pathways that can assume the function that was lost (contralesional plasticity). While both patterns have been demonstrated in patient groups following injury, the specific mechanisms underlying each mode of plasticity are poorly understood. In a retrospective case series of 13 patients, we utilize a novel paradigm that analyzes serial fMRI scans in patients harboring intrinsic brain tumors that vary in location and growth kinetics to better understand the mechanisms underlying these two modes of plasticity in the human primary motor cortex. Twelve patients in our series had some degree of primary motor cortex plasticity, an area previously thought to have limited plasticity. Patients harboring smaller lesions with slower growth kinetics and increasing distance from the primary motor region demonstrated recruitment of ipsilateral motor regions. Conversely, larger, faster-growing lesions in close proximity to the primary motor region were associated with activation of the contralesional primary motor cortex, along with increased activation of the supplementary motor area. These data increase our understanding of the adaptive abilities of the brain and may lead to improved treatment strategies for those suffering from motor loss secondary to brain injuries.