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1.
Eur Rev Med Pharmacol Sci ; 24(14): 7845-7854, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32744712

RESUMO

OBJECTIVE: Current trends show a rise of attention given to breast cancer patients' quality of life and the surgical reconstructive result. Along with this trend, surgical training quality and efficacy are gaining importance and innovative training methods such as online videos shared on social media portals, are becoming main updating tools. In hazardous times like COVID-19 pandemic nowadays, online communication becomes of vital importance and adaptation and innovation are fundamental to keep research and education alive. The authors aimed to investigate the role of video and multimedia sources on the daily activity and surgical training of a representative group of surgeons specifically dedicated to oncologic, oncoplastic and reconstructive breast surgeries. MATERIALS AND METHODS: A survey was produced and administered to 20 major Italian Breast Centers. Collected data were analyzed with Fisher's Exact Test. RESULTS: From October 2019 to March 2020, a total of 320 surveys were collected. Among the responders, there were 188 trainees (intern medical doctors and residents) and 110 faculty, 72% of them belonged to a plastic surgery environment, while 28% to general surgery environment. Almost all respondents have ever watched videos concerning breast surgery. CONCLUSIONS: The results of the study show how breast surgeons rely on videos and web platforms, mostly YouTube, when searching for training info about surgical procedures. Social media offer great opportunities for sharing knowledge and diffusion of new ideas but greater attention to their reliability is mandatory.


Assuntos
Infecções por Coronavirus/patologia , Educação a Distância/normas , Pneumonia Viral/patologia , Cirurgiões/psicologia , Betacoronavirus/isolamento & purificação , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , COVID-19 , Infecções por Coronavirus/virologia , Feminino , Humanos , Mastectomia , Pandemias , Pneumonia Viral/virologia , Qualidade de Vida , SARS-CoV-2 , Mídias Sociais , Inquéritos e Questionários , Gravação em Vídeo
2.
Neuropsychologia ; 43(3): 450-9, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15707620

RESUMO

The present study aimed to determine whether the bradykinesia of Parkinson's disease (PD) patients during the execution of reaching-grasping movements (i) is related to an impaired implementation of movement parameters and (ii) selectively involves the control of reach and/or grasp movements. We compared the kinematics of reaching to grasp of differently sized objects placed at different positions, among PD patients in the early stage of disease (ESPD), in the advanced stage of disease (ASPD) without L-dopa medication (off-state), and in healthy controls. In addition, we analysed the effects of L-dopa replacement therapy by comparing the kinematics of the patients in the advanced stage of disease after L-dopa administration with those of the other groups. Bradykinesia increased with disease progression, but only in the initial phases of the reach and grasp components. However at both stages of the disease, the kinematics of reaching and grasping responded to extrinsic and intrinsic object properties just as in controls. L-dopa administration improved the performance of PD patients, though this was more evident for the reach than for the grasp. We suggest that the basal ganglia (BG) are involved in implementing kinematic parameters, but neither (or only marginally) in the initial movement parameterization itself, nor in the on-line control of movement. Specifically, the BG dysfunction in PD induces a slowed implementation of movement parameters. The lack of effect of L-dopa administration on grasp kinematics may be because the motor control of distal effectors is less represented in the motor circuitry formed by the supplementary motor area (SMA), thalamus and BG.


Assuntos
Gânglios da Base/fisiologia , Hipocinesia/etiologia , Hipocinesia/fisiopatologia , Doença de Parkinson/complicações , Idoso , Antiparkinsonianos/administração & dosagem , Antiparkinsonianos/farmacologia , Fenômenos Biomecânicos , Estudos de Casos e Controles , Progressão da Doença , Feminino , Humanos , Levodopa/administração & dosagem , Levodopa/farmacologia , Masculino , Pessoa de Meia-Idade , Transtornos das Habilidades Motoras/fisiopatologia , Doença de Parkinson/fisiopatologia , Índice de Gravidade de Doença , Análise e Desempenho de Tarefas
3.
Neuropsychologia ; 35(12): 1577-82, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9460728

RESUMO

In the present study we attempted to determine the nature of the visual analysis that is performed on an object in order to grasp it. We required eight healthy subjects to reach and grasp a wooden bar which was superimposed over the shaft of the Müller-Lyer illusion. Vision of both the hand and the bar was allowed. Three different bar lengths were used. Two additional control tasks in which the subjects were required to reproduce the length of the shafts were carried out. The results showed that hand shaping while grasping the bar was influenced by the illusion configurations on which it was superimposed. However, this effect was smaller than that observed in the two tasks of length reproduction. These results support the notion that visual analysis performed on the object of a grasp movement is global and takes into account the object itself, as well as its relationships with surrounding cues. We propose, as suggested previously for reaching movements (Gentilucci, M. et al., Neuropsychologia, 1996, 34, 369-376), two partially independent stages during visuo-motor integration for grasping an object. In the first stage, the object is coded inside an object-centred frame of reference. In the second stage it is transposed in an egocentric frame of reference, in which the spatial relations between object and agent are computed. In this second stage the influence of cues surrounding the target is minimized.


Assuntos
Ilusões/psicologia , Desempenho Psicomotor/fisiologia , Percepção Visual/fisiologia , Adulto , Feminino , Humanos , Masculino
4.
Neuropsychologia ; 30(10): 877-97, 1992 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1436435

RESUMO

In this investigation we studied the influence of object velocity on the transport and on the grasp components of prehension movements directed to approaching objects. Three experiments were carried out. In the first experiment six subjects were required to reach and grasp a sphere that approached them with a constant velocity. The effects of four velocities were studied. The results showed that the end point of the arm movement changed with object velocity: nearer the body with higher than with lower object velocities. Transport velocity increased with movement amplitude and the deceleration phase decreased in duration with higher object velocities. On the contrary the grasp component was not affected by object velocity. The second experiment was a control experiment carried out in order to verify whether a possible influence of object velocity on the grasp could be revealed in an experimental condition in which grasp planning relies without doubt on visual computation of all object features. In this experiment object velocity and object size were randomly varied. The results showed that the grasp was not influenced by object velocity, whereas it was sensitive to changes of object size. The third experiment had the two-fold aim of establishing (1) whether transport velocity was influenced by object velocity once the location in space at which the object had to be grasped was fixed and (2) whether the grasp kinematics differed for prehension movements directed respectively to stationary or to moving objects. Results showed that the first part of the transport is affected only by distance, whereas the deceleration phase decreased with increasing object velocity. This last result suggests that subjects minimized object displacements in order to grasp the sphere correctly. The grasp component differed between the conditions of stationary and moving stimuli only in the relative timing between finger aperture and closure phases. The closure phase decreased in the condition of moving stimuli. The results of the three experiments indicate the dependence of transport parameters on object velocity, whereas grasp parameters appear to be unaffected.


Assuntos
Atenção , Percepção de Distância , Percepção de Movimento , Orientação , Desempenho Psicomotor , Aceleração , Adulto , Aprendizagem por Discriminação , Percepção de Forma , Humanos , Cinestesia , Masculino , Propriocepção , Psicofísica , Tempo de Reação , Percepção do Tempo
5.
Neuropsychologia ; 39(2): 132-9, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11163371

RESUMO

The aim of the present study was to determine whether children like adults (Gentilucci M, Chieffi S, Daprati E, Saetti MC, Toni I. Visual illusion and action. Neuropsychologia 1996;34:369-76; Gentilucci M, Daprati E, Gangitano M, Toni I. Eye position tunes the contribution of allocentric and egocentric information to target localisation in human goal directed arm movements. Neurosci Lett 1997;222:123-6) are influenced by visual illusions when they transform visual information in motor command. Children and adults pointed to a shaft extremity of the Müller-Lyer configurations, as well as to an extremity of a control configuration. Movements were executed in two experimental conditions. In the vision condition subjects saw both the stimulus and their hand before and during movement. In the no vision (memory) condition subjects saw the stimulus and their hand before, but not during movement. Movement started 5 s after vision was precluded. The Müller-Lyer illusion affected pointing kinematics of both children and adults. As found previously (Gentilucci M, Chieffi S, Daprati E, Saetti MC, Toni I. Visual illusion and action. Neuropsychologia 1996;34:369-76; Gentilucci M, Daprati E, Gangitano M, Toni I. Eye position tunes the contribution of allocentric and egocentric information to target localisation in human goal directed arm movements. Neurosci Lett 1997;222:123-6), subjects undershot and overshot the shaft extremity of the closed and of the open configuration, respectively. The illusion effect was greater in the no vision than in the vision condition. These results show that in children like in adults the system underlying visual perception in an object-centered frame of reference and that involved in motor control functionally interact with each other. Although the processes of target localisation were the same, the transformation of target position information in a sequence of motor patterns was different in children from that in adults. Even if both children and adults lengthened duration of the deceleration phase in the vision condition, only adults shortened duration of the acceleration phase in order to maintain constant movement time (Viviani P, Schneider R. A developmental study of the relationship between geometry and kinematics in drawing movements. J Exp Psychol 1991;17:198-218). This result suggests that children are yet unable to co-ordinate temporally acceleration with deceleration phase.


Assuntos
Braço , Movimento , Ilusões Ópticas , Desempenho Psicomotor , Percepção Visual , Aceleração , Adulto , Análise de Variância , Criança , Feminino , Humanos , Masculino , Psicofísica
6.
Neuropsychologia ; 34(5): 369-76, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-9148193

RESUMO

The role of allocentric cues on movement control was investigated in the present study. Pointing movements directed to the more distant vertex of closed and open configurations of the Muller-Lyer illusion, as well as to the vertex of control lines, were studied in four experimental conditions. In the first (full-vision condition) subjects saw both stimulus and their hand before and during movement, in the second (non-visual feedback condition) they saw the stimulus, but not their hand during movement. In the two remaining conditions (no-vision conditions) vision of the scene and the hand was precluded. Pointing was executed 0 sec (no vision 0 sec delay condition) or 5 sec (no-vision 5 sec delay condition) after the light was switched off. The Muller-Lyer illusion affected pointing kinematics with respect to the control lines. Subjects undershot and overshot the vertex location, respectively, of the closed and open configuration. Correspondingly, the entire kinematics were changed. The main result was, however, a gradually increasing effect of the perceptual illusion when pointing was executed from memory compared to the full-vision condition. These data are discussed according to the hypothesis that the system underlying visual perception in the allocentric frame of reference and that involved in motor action can functionally interact. The strength of this interaction depends upon the efficiency of the egocentric frame of reference by which motor actions are constructed.


Assuntos
Ilusões/fisiologia , Movimento/fisiologia , Adolescente , Adulto , Sinais (Psicologia) , Retroalimentação/fisiologia , Feminino , Mãos/fisiologia , Humanos , Masculino , Estimulação Luminosa , Desempenho Psicomotor/fisiologia
7.
Neuropsychologia ; 29(5): 361-78, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1886680

RESUMO

The main aim of the present study was to clarify whether different types of grasping may affect the transport component of prehension movements. To this purpose two experiments were carried out. In the first experiment the kinematics of arm movements (transport and manipulation components) were studied in eight normal subjects instructed to reach and grasp different objects located either 20 or 30 cm from their hand. The objects employed required two different types of grip: prehension with the whole hand and prehension with the index finger and the thumb (precision grip). In the second experiment subjects were instructed to point to the same objects employed in the first experiment. This experiment served as a control for the precision requirements related to the object size. The results showed that, once the precision requirements were taken into account, the transport component remained unmodified with the different types of grip. The time course of the manipulation component and its temporal relations with the transport component changed with the type of grasping. The maximal hand aperture was reached earlier in the precision grip than in the whole hand prehension and the temporal coupling with the transport component was weaker in the former condition than in the latter. The data are interpreted as further evidence in favour of independence between the transport and the manipulation "channels".


Assuntos
Braço/fisiologia , Mãos/fisiologia , Movimento/fisiologia , Adolescente , Humanos , Masculino , Estimulação Luminosa , Fatores de Tempo
8.
Neuropsychologia ; 38(10): 1398-404, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10869583

RESUMO

The kinematics of the action formed by reaching-grasping an object and placing it on a second target was studied in a patient who suffered from an acute vascular left brain lesion, which affected the Supplementary Motor Area proper (SMA-proper) (Matelli M, Luppino G. Thalamic input to mesial and superior area 6 in the macaque monkey. Journal of Comparative Neurology 1996;372:59-87, Matelli M, Luppino G, Fogassi L, Rizzolatti G. Thalamic input to inferior area 6 and area 4 in the macaque monkey. Journal of Comparative Neurology 1989;280:468-488), and in five healthy control subjects. The reach kinematics of the controls was affected by the positions of both the reaching-grasping and the placing targets (Gentilucci M, Negrotti A, Gangitano M. Planning an action. Experimental Brain Research 1997;115:116-28). In contrast, the reach kinematics of the patient was affected only by the position of the reaching-grasping target. By comparing these results with those previously found in Parkinson's disease patients executing the same action (Gentilucci M, Negrotti A. Planning and executing an action in Parkinson's disease patients. Movement Disorders 1999;1:69-79, Gentilucci M, Negrotti A. The control of an action in Parkinson's disease. Experimental Brain Research 1999;129:269-277), we suggest that the anatomical "motor" circuit formed by SMA-proper (see above), Basal Ganglia (BG) and Thalamus (Alexander GE, Crutcher MD. Functional architecture of basal ganglia circuits: neural substrates of parallel processing. Trends in the Neurosciences 1990;13:266-271, Hoover JE, Strick PL. Multiple output channels in the basal ganglia. Nature 1993;259:819-821) may be involved in the control of actions: SMA-proper assembles the sequence of the action, whereas BG updates its parameters and stores them.


Assuntos
Ataxia/etiologia , Lobo Frontal/fisiopatologia , Córtex Motor/fisiopatologia , Destreza Motora , Acidente Vascular Cerebral/complicações , Aceleração , Adulto , Braço , Feminino , Lobo Frontal/patologia , Lateralidade Funcional , Força da Mão , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Córtex Motor/patologia , Tempo de Reação , Recuperação de Função Fisiológica
9.
Am J Cardiol ; 80(1): 96-8, 1997 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-9205032

RESUMO

Fossa ovalis membrane aneurysm was diagnosed by transesophageal echocardiography in 45 of 134 consecutive patients (34%) with embolic cerebrovascular ischemic events. A potential cardiovascular source of embolism, other than the fossa ovalis membrane aneurysm, was found in 91% of these patients (41 of 45).


Assuntos
Isquemia Encefálica/complicações , Cardiopatias/complicações , Aneurisma Intracraniano/etiologia , Trombose/complicações , Adulto , Idoso , Ecocardiografia , Feminino , Cardiopatias/diagnóstico por imagem , Comunicação Interatrial/complicações , Comunicação Interatrial/epidemiologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade
10.
Brain Res Cogn Brain Res ; 6(3): 185-92, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9479070

RESUMO

The visual control of our own hand when dealing with an object and the observation of interactions between other people's hand and objects can be involved in the construction of internal representations of our own hand, as well as in hand recognition processes. Therefore, a different effect on handedness recognition is expected when subjects are presented with hands holding objects with either a congruent or an incongruent type of grip. Such an experiment was carried out on right-handed and left-handed subjects. We expected that the different degree of lateralisation in motor activities observed in the two populations [J. Herron, Neuropsychology of left-handedness, Academic Press, New York, 1980.] could account for the construction of different internal hand representations. As previously found [L.M. Parsons, Imaged spatial transformations of one's hands and feet, Cogn. Psychol., 19 (1987) 178-241.], in order to identify handedness, subjects mentally rotated their own hand until it matched with the presented one. This process was confirmatory, being preceded by an implicit visual analysis of the target hand. Presentation of hands holding objects with congruent or incongruent types of grip influenced handedness recognition at different stages in right-handed and left-handed subjects. That is, the mental rotation stage was affected in right-handed subjects, whereas the initial phase of implicit hand analysis was affected in left-handed subjects. We suggest that in handedness recognition, left-handers relied more on a pictorial hand representation, whereas right-handers relied more on a pragmatic hand representation, probably derived from experience in the control of their own movements. The use of different hand representations may be due to differential activation of temporal and premotor areas.


Assuntos
Lateralidade Funcional/fisiologia , Mãos/inervação , Desempenho Psicomotor/fisiologia , Adulto , Análise de Variância , Feminino , Força da Mão , Humanos , Masculino , Tempo de Reação/fisiologia , Rotação
11.
Brain Res Cogn Brain Res ; 9(2): 125-35, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10729696

RESUMO

The present study aimed to demonstrate that motor representations are used to recognise biological stimuli. In three experiments subjects were required to judge laterality of hands and forearms presented by pictures. The postures of the hands were those assumed when holding a small, medium and large sphere. In experiment 1, the sphere held in hand was presented, whereas in experiment 2 it was absent. In experiment 3, the same images, showing holding-a-sphere hands, as in experiment 1 were presented, but without forearm. In all experiments one finger of each hand could be absent. In experiment 1 recognition time was longer for those hand postures for which the corresponding grasping motor acts required more accuracy. This was confirmed by a control experiment (experiment 4), in which subjects actually grasped the spheres. Absence of fingers did not influence right-left hand recognition. However, the absence of target object in experiment 2, and of forearm in experiment 3 reduced the effects of the type of holding on hand laterality recognition. The results of the present study indicate that grasp representations are used to recognise hand laterality. In particular, the visual description of how hand and object interact in space (the opposition space [M.A. Arbib, Programs, schemas and neural networks for control of hand movement: beyond the RS frameworks, in: M. Jeannerod (Ed.), Attention and Performance XIII: Motor Representation and Control, Lawrence Erlbaum, Hillsdale, NJ, 1990, 111-138; M.A. Arbib, T. Iberall, D. Lyons, Coordinated control programs for movements of the hand, in: A.W. Goodman, I. Darian-Smith (Eds.), Hand function and the neocortex, Springer, Berlin, 1985, pp. 135-170]) and the anchoring of the hand to the agent are the features of the grasp representations used in hand-recognition processes. The data are discussed according to the more general notion that motor representations are automatically extracted in the process of intuiting situations, or people's intentions. These motor representations, which are compared with those of other people, contain concrete information on the actions (the motor program) by which a situation is created and on the aim of the agents executing those actions.


Assuntos
Percepção de Forma/fisiologia , Lateralidade Funcional/fisiologia , Força da Mão/fisiologia , Tato/fisiologia , Adulto , Fenômenos Biomecânicos , Feminino , Dedos , Antebraço , Humanos , Masculino , Memória/fisiologia , Orientação/fisiologia , Estimulação Luminosa
12.
Neuroreport ; 9(5): 887-91, 1998 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-9579685

RESUMO

We used an interference paradigm in order to study integration between haptic and visual information in motor control and in perceptual analysis. Subjects either reached and grasped a visually presented sphere or matched its size with their left hand while manipulating with their right hand another sphere whose size could be smaller or greater. In four experiments haptic analysis of the manipulated sphere could be either automatically incorporated with or explicitly dissociated from visual analysis. In a fifth experiment reaching-grasping and matching were executed with the right hand, whereas manipulation was executed with the left hand. Manipulation with the right hand influenced finger shaping during grasping with the left hand when the sizes of the two objects were different. Interference was observed mainly in those experiments in which haptic analysis could be automatically integrated with visual analysis. In the matching task, no effect was observed. Finally, manipulation with the left hand did not produce any interference effect on reaching-grasping and matching executed by the right hand. The results of the present study suggest that somesthetic information is integrated with visual information only in sensorimotor transformations. In addition, they support the notion that the left hemisphere together with the right hemisphere is involved in the control of left hand reaching-grasping movements.


Assuntos
Lateralidade Funcional/fisiologia , Força da Mão/fisiologia , Desempenho Psicomotor/fisiologia , Percepção Visual/fisiologia , Adulto , Feminino , Dedos/inervação , Dedos/fisiologia , Humanos , Masculino , Estimulação Luminosa
13.
Neuroreport ; 7(2): 589-92, 1996 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-8730836

RESUMO

Subjects were required to reach and grasp a parallelepiped, the position, orientation and size of which were varied. The kinematics of reaching and grasping movements was studied in full vision and in no vision conditions. Both direction and movement amplitude of reaching were affected by object orientation. Conversely, both the time course of finger axis orientation and the angular displacement of the hand at wrist were influenced by object position. These results were not modified by the absence of visual control. Finger aperture during grasping was affected by both object size and orientation. This latter result was not due to a distorted size perception, as shown by a control matching experiment. Taken together, the results of the present study suggest the integration between distal and proximal components during reaching and grasping.


Assuntos
Mãos/fisiologia , Movimento/fisiologia , Orientação/fisiologia , Adulto , Retroalimentação/fisiologia , Feminino , Dedos/inervação , Dedos/fisiologia , Mãos/inervação , Humanos , Iluminação , Masculino , Percepção/fisiologia , Visão Ocular/fisiologia
14.
Behav Brain Res ; 47(1): 71-82, 1992 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-1571102

RESUMO

The temporal coupling between the transport and grasp components of prehension movements was investigated through two experiments. In Experiment 1, six normal subjects were required to reach and grasp each of three spheres located at three different distances (Blocked trials). In Experiment 2, a visual perturbation paradigm was used in which the location of the object to be reached and grasped could change at the beginning of arm movement (Perturbed trials). The same subjects participated in both experiments. Kinematics of wrist trajectory (transport component) and of distance between thumb and index finger (grasp component) were analyzed. The results of Experiment 1 showed that the two components could be temporally coupled during their time course. In Experiment 2, the visual perturbation affected both the components, but different times were required by each component to reorganize the movement towards the new target. These different times caused the decoupling of those events that appeared synchronized in Experiment 1. Finally, evidence was found to suggest that planning of grip formation takes into account not only the perceived characteristics of the object, but also the time planned by the transport component to reach the object.


Assuntos
Atenção , Destreza Motora , Orientação , Desempenho Psicomotor , Percepção do Tempo , Aceleração , Adolescente , Adulto , Humanos , Cinestesia , Masculino , Mascaramento Perceptivo , Propriocepção
15.
Behav Brain Res ; 2(2): 125-46, 1981 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7248054

RESUMO

The afferent properties of single neurons of the periarcuate cortex have been studied in the macaque monkey. Most of the recorded neurons responded to stimuli in one or two sensory modalities and, accordingly, they were classified as somatosensory, visual or bimodal (visual and somatosensory) neurons. Visual neurons were located rostral to the arcuate sulcus, whereas the somatosensory and the bimodal neurons were found predominantly caudal to this sulcus. Somatosensory neurons (n = 102) and bimodal neurons (n = 69) had identical somatic afferent properties. They were subdivided into 'tactile' neurons, 'joint' neurons and 'tactile and joint' neurons. 'Tactile' neurons (70%) had their receptive fields formed either by one or by two or more spatially separated responding areas. The parts of the body most represented were the hands and the mouth. 'Joint' neurons (10%) were activated by the rotation of one or, more often, of two or more articulations. The movement of the hand towards the mouth was the most frequently represented movement. 'Tactile and joint' neurons (20%) responded to both tactile and joint stimulation having receptive field locations and properties like those of the other two classes of neurons. Some 'joint' and 'tactile and joint' neurons had summing properties, i.e. their response to tactile or joint stimulation was conditional upon a simultaneous stimulation of another articulation. The data are interpreted as evidence in favor of the existence of an area in the agranular cortex that organizes the mouth and the hand to mouth movements.


Assuntos
Lobo Frontal/fisiologia , Percepção/fisiologia , Vias Aferentes/fisiologia , Animais , Sincronização Cortical , Mãos/inervação , Articulações/inervação , Macaca fascicularis , Macaca nemestrina , Mecanorreceptores/fisiologia , Boca/inervação , Neurônios/fisiologia , Pele/inervação , Tato/fisiologia , Percepção Visual/fisiologia
16.
Behav Brain Res ; 2(2): 147-63, 1981 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7248055

RESUMO

The visual response of single neurons of the periarcuate cortex have been studied in the macaque monkey. Two sets of neurons responding to visual stimuli have been found. The first set, located rostral to the arcuate sulcus, was formed by units that could be activated by stimuli presented far from the animal. These neurons had large receptive fields and were neither orientation nor direction selective. The second set, found predominantly caudal to the arcuate sulcus, was formed by units that were maximally or even exclusively activated by stimuli presented in the space immediately around the animal. These neurons were bimodal, responding also to somatosensory stimuli. According to the location of their visual responding regions the bimodal neurons were subdivided into pericutaneous (54%) and distant peripersonal neurons (46%). The former responded best to stimuli presented a few centimeters from the skin, the latter to stimuli within the animal's reaching distance. The visual responding regions were spatially related to the tactile fields. It is argued that neurons with a receptive field consisting of several responding areas, some in one sensory modality, some in another, have a praxic function and that they are involved in organizing sequences of movements.


Assuntos
Lobo Frontal/fisiologia , Percepção Visual/fisiologia , Animais , Percepção de Distância/fisiologia , Potenciais Evocados , Mãos/inervação , Articulações/inervação , Macaca fascicularis , Macaca nemestrina , Boca/inervação , Neurônios/classificação , Neurônios/fisiologia , Pele/inervação , Percepção Espacial/fisiologia , Tato/fisiologia , Vias Visuais/fisiologia
17.
Behav Brain Res ; 60(1): 91-113, 1994 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-8185856

RESUMO

We mapped the motor areas of the prosimian Galago crassicaudatus using intracortical electrical microstimulation and morphological and histochemical (cytochrome oxidase) techniques. Stimulation data showed that on the brain convexity there is an area (area Frontalis posterior, F post.) from which movements could be evoked at low threshold (< 10 microA). This area is somatotopically organized, with the leg represented medially, the arm centrally and the face and mouth laterally. Proximal and distal movements are not segregated. Most of the evoked movements, even at threshold, consist of movements involving two or more joints. F post. is characterized by a three-band cytochrome oxidase activity pattern. It has an agranular structure, but it lacks pyramidal cells that are larger than those observed in other areas. In front of F post. there is an area histochemically similar to it, Frontalis intermedialis (F int.). This area consists of two cytoarchitectonic divisions: an agranular division (F int. pars caudalis) and a disgranular division (F int. pars rostralis). The excitability threshold of F int. is relatively high (10 to 30 microA). Eye, ear and neck movements are elicited from its lateral part, whereas trunk movements associated with limb movements are elicited from its medial part. Caudal to F post., there is another region from which movements can be evoked with currents between 10 to 30 microA. This region has the same medio-lateral somatotopic arrangement of F post. Typically, single joint movements are elicited from it. Proximal and distal movements are not segregated. In spite of its homogeneity in terms of motor response, the posterior excitable region is formed by two anatomically separate areas: anterior somatic area (S ant.) and posterior somatic area (S post.). S ant. has a typical koniocortex structure, whereas S post, resembles the parakoniocortex as defined by Sanides (J. Hirnforsch., 9 (1967) 225-252). Histochemically both areas are made up of four longitudinal stripes differing for enzymatic activity. The three superficial stripes tend to merge together and are sharply separated from a deeply located, light stripe. This stripe is homogeneous in S ant., whilst its central part shows an increase in activity in S post. The possible homologies between the motor and somatic areas of the galago and monkey as well as their role in movement control are discussed.


Assuntos
Complexo IV da Cadeia de Transporte de Elétrons/fisiologia , Lobo Frontal/fisiologia , Atividade Motora/fisiologia , Músculos/inervação , Lobo Parietal/fisiologia , Animais , Mapeamento Encefálico , Dominância Cerebral/fisiologia , Estimulação Elétrica , Músculos Faciais/inervação , Membro Anterior/inervação , Galago , Membro Posterior/inervação , Córtex Motor/fisiologia , Boca/inervação , Neurônios/fisiologia , Córtex Somatossensorial/fisiologia
18.
Brain Res ; 225(2): 421-4, 1981 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-7306798

RESUMO

Single neurons were recorded from the "mouth area" of the postarcuate cortex in macaque monkeys. According to their responses to somatosensory stimuli and their activity during the animal's movements, the neurons were subdivided into three classes: (1) neurons activated only by external stimuli; (2) neurons showing an enhancement of their response when a specific motor act followed the external stimulation; (3) neurons responding reliably to external stimuli only if the stimulation triggered a specific, related motor act. Of the recorded neurons, 50% also responded to visual stimuli.


Assuntos
Córtex Motor/fisiologia , Neurônios/fisiologia , Animais , Lateralidade Funcional , Macaca nemestrina
19.
Neurosci Lett ; 222(2): 123-6, 1997 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-9111744

RESUMO

Subjects were required to point to the distant vertex of the closed and the open configurations of the Müller-Lyer illusion using either their right hand (experiment 1) or their left hand (experiment 2). In both experiments the Müller-Lyer figures were horizontally presented either in the left or in the right hemispace and movements were executed using either foveal or peripheral vision of the target. According to the illusion effect, subjects undershot and overshot the vertex location of the closed and the open configuration, respectively. The illusion effect decreased when the target was fixated and when the stimulus was positioned in the right hemispace. These results confirm the hypothesis that both egocentric and allocentric information are combined in order to encode target position in space. When movements are directed to foveal targets, decreasing effects of allocentric cues, as shown by decreasing the illusion effect, could be due to enhanced efficiency of the egocentric system. That is, information on eye position when target is fixated can be used to precisely establish its spatial relations with the body. In addition, a more accurate analysis of allocentric information is hypothesized when the target is positioned in the left hemispace. In other words, our data confirm the notion that the right cerebral hemisphere is involved in space representation.


Assuntos
Movimentos Oculares/fisiologia , Desempenho Psicomotor/fisiologia , Adulto , Braço/fisiologia , Dominância Cerebral/fisiologia , Humanos , Ilusões/fisiologia , Gravação em Vídeo
20.
Ital Heart J ; 1(6): 426-30, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10929744

RESUMO

BACKGROUND: Abnormalities of the skeletal muscle vasculature, such as endothelial dysfunction and reduced microvascular density, can be reversed by physical training in patients with chronic heart failure. The molecular mechanisms that mediate the beneficial effects of physical training on the vascular endothelium are unknown. METHODS: Endothelial nitric oxide synthase (eNOS) and vascular endothelial growth factor (VEGF) gene expression in the skeletal muscle, peak oxygen consumption (VO2) and calf peak reactive hyperemia were measured before and after 12 weeks of supervised physical training in 10 patients with chronic heart failure. Five patients with heart failure of similar severity who did not participate in the training program served as controls. RESULTS: The effects of physical training on eNOS and VEGF gene expression were heterogeneous. eNOS gene expression increased 3-4 fold in 4 patients while it remained constant in 6 patients. VEGF gene expression increased significantly in all patients who were not treated with beta-adrenergic blockade and remained constant in all patients who were treated with beta-adrenergic blockade. In contrast, physical training increased peak VO2 and calf peak reactive hyperemia in all patients. Mean peak VO2 increased from 13.13 +/- 2.21 to 16.19 +/- 2.69 ml/kg/min (p < 0.001) and calf peak reactive hyperemia increased from 19.7 +/- 2.3 to 29.6 +/- 4.0 ml*min(-1)*100 ml(-1) (p < 0.001). CONCLUSIONS: A supervised program of physical training that consistently enhanced peak VO2 and vascular reactivity in patients with chronic heart failure increased or left eNOS and VEGF gene expression unchanged in skeletal muscle. Changes in vascular endothelial gene expression may contribute to the benefits of training on vascular endothelial function but are not solely responsible for these benefits.


Assuntos
Fatores de Crescimento Endotelial/metabolismo , Endotélio Vascular/enzimologia , Exercício Físico , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/terapia , Linfocinas/metabolismo , Óxido Nítrico Sintase/metabolismo , Idoso , Doença Crônica , Feminino , Regulação da Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Insuficiência Cardíaca/enzimologia , Humanos , Hiperemia , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/metabolismo , Consumo de Oxigênio , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
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