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PloS One 2015Eyelid opening stretches mechanoreceptors in the supratarsal Müller muscle to activate the proprioceptive fiber supplied by the trigeminal mesencephalic nucleus. This...
Eyelid opening stretches mechanoreceptors in the supratarsal Müller muscle to activate the proprioceptive fiber supplied by the trigeminal mesencephalic nucleus. This proprioception induces reflex contractions of the slow-twitch fibers in the levator palpebrae superioris and frontalis muscles to sustain eyelid and eyebrow positions against gravity. The cell bodies of the trigeminal proprioceptive neurons in the mesencephalon potentially make gap-junctional connections with the locus coeruleus neurons. The locus coeruleus is implicated in arousal and autonomic function. Due to the relationship between arousal, ventromedial prefrontal cortex, and skin conductance, we assessed whether upgaze with trigeminal proprioceptive evocation activates sympathetically innervated sweat glands and the ventromedial prefrontal cortex. Specifically, we examined whether 60° upgaze induces palmar sweating and hemodynamic changes in the prefrontal cortex in 16 subjects. Sweating was monitored using a thumb-mounted perspiration meter, and prefrontal cortex activity was measured with 45-channel, functional near-infrared spectroscopy (fNIRS) and 2-channel NIRS at Fp1 and Fp2. In 16 subjects, palmar sweating was induced by upgaze and decreased in response to downgaze. Upgaze activated the ventromedial prefrontal cortex with an accumulation of integrated concentration changes in deoxyhemoglobin, oxyhemoglobin, and total hemoglobin levels in 12 subjects. Upgaze phasically and degree-dependently increased deoxyhemoglobin level at Fp1 and Fp2, whereas downgaze phasically decreased it in 16 subjects. Unilateral anesthetization of mechanoreceptors in the supratarsal Müller muscle used to significantly reduce trigeminal proprioceptive evocation ipsilaterally impaired the increased deoxyhemoglobin level by 60° upgaze at Fp1 or Fp2 in 6 subjects. We concluded that upgaze with strong trigeminal proprioceptive evocation was sufficient to phasically activate sympathetically innervated sweat glands and appeared to induce rapid oxygen consumption in the ventromedial prefrontal cortex and to rapidly produce deoxyhemoglobin to regulate physiological arousal. Thus, eyelid opening with trigeminal proprioceptive evocation may activate the ventromedial prefrontal cortex via the mesencephalic trigeminal nucleus and locus coeruleus.
Topics: Adult; Brain Stem; Eyelids; Female; Hemoglobins; Humans; Male; Mechanoreceptors; Neurovascular Coupling; Prefrontal Cortex; Proprioception; Sweat Glands; Sweating; Trigeminal Nuclei
PubMed: 26244675
DOI: 10.1371/journal.pone.0134659 -
International Journal of... Dec 2014We present the first quantitative characterization of electrodermal activity (EDA) patterns on the wrists of healthy adults during sleep using dry electrodes. We compare...
We present the first quantitative characterization of electrodermal activity (EDA) patterns on the wrists of healthy adults during sleep using dry electrodes. We compare the new results on the wrist to the prior findings on palmar or finger EDA by characterizing data measured from 80 nights of sleep consisting of 9 nights of wrist and palm EDA from 9 healthy adults sleeping at home, 56 nights of wrist and palm EDA from one healthy adult sleeping at home, and 15 nights of wrist EDA from 15 healthy adults in a sleep laboratory, with the latter compared to concurrent polysomnography. While high frequency patterns of EDA called "storms" were identified by eye in the 1960s, we systematically compare thresholds for automatically detecting EDA peaks and establish criteria for EDA storms. We found that more than 80% of the EDA peaks occurred in non-REM sleep, specifically during slow-wave sleep (SWS) and non-REM stage 2 sleep (NREM2). Also, EDA amplitude is higher in SWS than in other sleep stages. Longer EDA storms were more likely to occur in the first two quarters of sleep and during SWS and NREM2. We also found from the home studies (65 nights) that EDA levels were higher and the skin conductance peaks were larger and more frequent when measured on the wrist than when measured on the palm. These EDA high frequency peaks and high amplitude were sometimes associated with higher skin temperature, but more work is needed looking at neurological and other EDA elicitors in order to elucidate their complete behavior.
Topics: Adolescent; Adult; Female; Galvanic Skin Response; Humans; Longitudinal Studies; Male; Microelectrodes; Polysomnography; Sleep Stages; Wireless Technology; Wrist; Young Adult
PubMed: 25286449
DOI: 10.1016/j.ijpsycho.2014.09.011 -
Physiological Research 2013In this study, we tested the hypothesis that experimental stress induces a specific change of left-right electrodermal activity (EDA) coupling pattern, as indexed by...
In this study, we tested the hypothesis that experimental stress induces a specific change of left-right electrodermal activity (EDA) coupling pattern, as indexed by pointwise transinformation (PTI). Further, we hypothesized that this change is associated with scores on psychometric measures of the chronic stress-related psychopathology. Ninety-nine university students underwent bilateral measurement of EDA during rest and stress-inducing Stroop test and completed a battery of self-report measures of chronic stress-related psychopathology. A significant decrease in the mean PTI value was the prevalent response to the stress conditions. No association between chronic stress and PTI was found. Raw scores of psychometric measures of stress-related psychopathology had no effect on either the resting levels of PTI or the amount of stress-induced PTI change. In summary, acute stress alters the level of coupling pattern of cortico-autonomic influences on the left and right sympathetic pathways to the palmar sweat glands. Different results obtained using the PTI, EDA laterality coefficient, and skin conductance level also show that the PTI algorithm represents a new analytical approach to EDA asymmetry description.
Topics: Adult; Algorithms; Female; Galvanic Skin Response; Humans; Lie Detection; Male; Psychometrics; Reproducibility of Results; Sensitivity and Specificity; Skin; Stress, Psychological
PubMed: 24359433
DOI: 10.33549/physiolres.932589 -
Cognitive and Behavioral Neurology :... Sep 2013Alexithymia, the inability to describe one's own emotions, is linked to deficits in empathy, manifesting as a diminished capacity to recognize or understand the emotions...
BACKGROUND
Alexithymia, the inability to describe one's own emotions, is linked to deficits in empathy, manifesting as a diminished capacity to recognize or understand the emotions and mental states of others. Several brain centers of autonomic control and interoception that are activated in empathy are thought to misfunction in alexithymia. We hypothesized that individual differences in autonomic changes under affective stimulation might be associated with differences in alexithymia and empathy.
METHODS
We studied 21 healthy volunteers, comparing their alexithymia and empathy scores with changes in their sympathetic autonomic arousal, indexed by the palmar skin potential level, during 3 tasks: playing a computer game, performing mental arithmetic, and watching a negative emotional valence video.
RESULTS
Both autonomic and subjective sense of arousal increased at the beginning of each task and then gradually subsided over the course of the task. Higher autonomic arousal at the onset of the computer game was associated with higher empathy scores, and at the onset of the negative video with higher scores for both empathy and alexithymia. Alexithymia delayed the habituation of autonomic arousal during the computer game, while the empathy score was related to a faster decline in arousal during the negative video task.
CONCLUSIONS
High alexithymia and high empathy scores were linked to increased autonomic arousal at the onset of emotional stimulation, but were distinguishable in the rates of habituation of the evoked arousal. Our data provide insight into the relationships among interacting psychological traits, physiologic regulation, and the arousal dimension of emotional experience.
Topics: Adult; Affect; Affective Symptoms; Arousal; Emotions; Empathy; Female; Galvanic Skin Response; Habituation, Psychophysiologic; Healthy Volunteers; Humans; Male; Mental Processes; Self-Assessment; Sympathetic Nervous System; Video Games; Young Adult
PubMed: 24077571
DOI: 10.1097/WNN.0000000000000002 -
Experimental Brain Research Aug 2013The purpose of this study was to investigate the effects of changes in the proprioceptive signals induced by muscle vibration on multi-finger interaction and... (Randomized Controlled Trial)
Randomized Controlled Trial
The purpose of this study was to investigate the effects of changes in the proprioceptive signals induced by muscle vibration on multi-finger interaction and coordination. We hypothesized that unintended force production by non-instructed fingers (enslaving) would increase with muscle vibration while synergy indices during steady-state force production would drop. The framework of the uncontrolled manifold hypothesis was used to quantify indices of multi-finger synergies stabilizing total force during steady-state force production and anticipatory changes in these indices (anticipatory synergy adjustments, ASAs) in preparation to a quick force pulse production with and without hand-muscle vibration at 80 Hz. The dominant hands of twelve healthy right-handed subjects were tested under three conditions: no vibration, vibration of the palmar surface of the hand, and vibration of the forearm applied over the flexor muscles. There were no significant effects of vibration on maximal voluntary force. The magnitude of enslaving was larger during vibration of the hand compared to the other two conditions. During steady-state force production, strong synergies stabilizing total force were seen in all three conditions; however, indices of force-stabilizing synergies were lower during vibration of the hand. Prior to the force pulse initiation, the synergy index started to drop earlier and over a larger magnitude without vibration compared to either vibration condition. Effects of vibration on enslaving and synergy index may be due to diffuse reflex effects of the induced afferent activity on alpha-motoneuronal pools innervating the extrinsic flexor compartments. We conclude that multi-finger synergies are not based on signals from muscle receptors. The smaller synergy indices and ASAs may reflect supraspinal effects of the vibration-induced afferent activity, in particular its interactions with trans-thalamic loops.
Topics: Adult; Feedback, Sensory; Female; Fingers; Humans; Male; Motor Skills; Muscle, Skeletal; Psychomotor Performance; Vibration
PubMed: 23736524
DOI: 10.1007/s00221-013-3597-y -
Critical Care (London, England) Mar 2013Many intensive care unit (ICU) patients describe pain and other adverse feelings that may impact long-term psychological morbidity. Sympathetically mediated palmar skin... (Observational Study)
Observational Study
INTRODUCTION
Many intensive care unit (ICU) patients describe pain and other adverse feelings that may impact long-term psychological morbidity. Sympathetically mediated palmar skin conductance variability is related to emotionally induced perspiration and correlates with pain levels in the perioperative setting but has not been studied in ICU patients.
METHODS
Twenty non-intubated and 20 intubated general ICU patients were included in this observational study. Patients were monitored with the MED-STORM Pain Monitoring System®. The number of skin conductance fluctuations per second (NSCF) was measured in parallel with bedside observation during one hour of intensive care, including rest, procedures and patient-staff interactions. Arousal-agitation level was monitored with the motor activity assessment scale (MAAS). Pain was monitored with the numeric rating scale (0 to 10) in patients able to communicate or by observation in patients unable to communicate.
RESULTS
In non-intubated patients, NSCF increased with increasing stimulation/pain but also with higher MAAS (P=0.002). An interaction effect was found, with increased NSCF response to stimulation/pain with increasing MAAS (P<0.001).
CONCLUSIONS
In critically ill patients, NSCF may be more useful evaluating emotional distress rather than pain alone. It needs to be assessed whether NSCF monitoring is clinically useful and whether controlling emotional distress with the aid of such monitoring may impact on patient care and outcomes.
Topics: Adult; Aged; Electric Stimulation; Female; Galvanic Skin Response; Humans; Intensive Care Units; Male; Middle Aged; Motor Activity; Pain; Pain Measurement; Prospective Studies
PubMed: 23510014
DOI: 10.1186/cc12571 -
Romanian Journal of Morphology and... 2012Gheorghe Marinescu (Georges Marinesco, in French) is a Romanian physician, founder of the School of Neurology in that country. He begins his medical studies in...
Gheorghe Marinescu (Georges Marinesco, in French) is a Romanian physician, founder of the School of Neurology in that country. He begins his medical studies in Bucharest, then has the opportunity to reach Paris and join the School of Neurology in La Salpêtrière Hospital, lead by Jean-Martin Charcot. This trip will forever imprint the mind of Marinescu, a great friend of France, a respectful student of Charcot and a friendly colleague of many Parisian neurologists. Marinescu's works are multiple and very important. He describes the succulent hand in syringomyelia and the palmar-jaw reflex. Marinescu is also one of the first to use the cinema for medical purposes. His work as an anatomo-clinician, a method developed by Charcot, is important. We denote the description of the locus niger affected by tuberculosis in a case of parkinsonism (this description paving Etienne Brissaud's way to highlight the anatomical origin of Parkinson's disease), the original clinical description of Marinesco-Sjögren syndrome, and that of medullomyoblastoma. Marinescu is also a famous neurocytologist as evidenced by his work, La Cellule Nerveuse, published in 1909. The first volume of the book is devoted to the aspects of the normal nervous tissue: the neurofibrillar network, the chromatophilic elements, and the paranucleolar corpuscles (now known as Marinescu's bodies). The second volume of the book is almost related to features revealed by experimental lesions: chromatolysis and neuronophagia. Furthermore, Marinescu describes with Oscar Blocq, small nodules than are now regarded as the first description of senile plaques.
Topics: History, 19th Century; History, 20th Century; Humans; Neurology; Romania
PubMed: 23303009
DOI: No ID Found -
International Journal of Pediatrics 2012The plantar grasp reflex is of great clinical significance, especially in terms of the detection of spasticity. The palmar grasp reflex also has diagnostic significance....
The plantar grasp reflex is of great clinical significance, especially in terms of the detection of spasticity. The palmar grasp reflex also has diagnostic significance. This grasp reflex of the hands and feet is mediated by a spinal reflex mechanism, which appears to be under the regulatory control of nonprimary motor areas through the spinal interneurons. This reflex in human infants can be regarded as a rudiment of phylogenetic function. The absence of the Moro reflex during the neonatal period and early infancy is highly diagnostic, indicating a variety of compromised conditions. The center of the reflex is probably in the lower region of the pons to the medulla. The phylogenetic meaning of the reflex remains unclear. However, the hierarchical interrelation among these primitive reflexes seems to be essential for the arboreal life of monkey newborns, and the possible role of the Moro reflex in these newborns was discussed in relation to the interrelationship.
PubMed: 22778756
DOI: 10.1155/2012/191562 -
Iranian Journal of Child Neurology 2012Congenital insensitivity to pain and anhidrosis (CIPA) or hereditary sensory autonomic neuropathies type IV (HSAN type IV) is an extremely rare autosomal recessive...
Congenital insensitivity to pain and anhidrosis (CIPA) or hereditary sensory autonomic neuropathies type IV (HSAN type IV) is an extremely rare autosomal recessive disorder initially described by Swanson in 1963. We report a 2.5-year-old boy with clinical features of CIPA as the first case in Iran. The symptoms included recurrent episodes of hyperthermia and unexplained fever that began in early infancy, anhidrosis (inability to sweat), profound loss of pain sensitivity, neurodevelopmental delay, unconscious self-mutilation of fingers, lips and tongue, corneal lacerations, palmar hyperkeratosis, non-painful fracture and joint deformities in the right ankle. Tearing, deep tendon reflexes and motor and sensory nerve action potentials were normal. Prenatal screening is the sole accessible option to prevent the birth of an affected child as no cure is available. Early recognition of CIPA patients and its orthopedic complications, prevention of accidental injuries, regular visual and eye follow-up and specific dental management could be useful in the reduction of frequency and severity of complications.
PubMed: 24665272
DOI: No ID Found -
Journal of Neurophysiology Jan 2012In humans, propriospinal neurons located at midcervical levels receive peripheral and corticospinal inputs and probably participate in the control of grip tasks, but...
In humans, propriospinal neurons located at midcervical levels receive peripheral and corticospinal inputs and probably participate in the control of grip tasks, but their role in reaching movements, as observed in cats and primates, is still an open question. The effect of ulnar nerve stimulation on flexor carpi radialis (FCR) motor evoked potential (MEP) was tested during reaching tasks and tonic wrist flexion. Significant MEP facilitation was observed at the end of reach during reach-to-grasp but not during grasp, reach-to-point, or tonic contractions. MEP facilitation occurred at a longer interstimulus interval than expected for convergence of corticospinal and afferent volleys at motoneuron level and was not paralleled by a change in the H-reflex. These findings suggest convergence of the two volleys at propriospinal level. Ulnar-induced MEP facilitation was observed when conditioning stimuli were at 0.75 motor response threshold (MT), but not 1 MT. This favors an increased excitability of propriospinal neurons rather than depression of their feedback inhibition, as has been observed during tonic power grip tasks. It is suggested that the ulnar-induced facilitation of FCR MEP during reach may be due to descending activation of propriospinal neurons, assisting the early recruitment of large motoneurons for rapid movement. Because the feedback inhibitory control is still open, this excitation can be truncated by cutaneous inputs from the palmar side of the hand during grasp, thus assisting movement termination. It is concluded that the feedforward activation of propriospinal neurons and their feedback control may be involved in the internal model, motor planning, and online adjustments for reach-to-grasp movements in humans.
Topics: Adult; Analysis of Variance; Biophysics; Electric Stimulation; Electromyography; Evoked Potentials, Motor; Female; Functional Laterality; H-Reflex; Hand; Hand Strength; Humans; Male; Movement; Muscle, Skeletal; Psychomotor Performance; Reaction Time; Recruitment, Neurophysiological; Transcranial Magnetic Stimulation; Ulnar Nerve; Wrist
PubMed: 22031772
DOI: 10.1152/jn.00774.2011