Neural pathways from the central nucleus of the amygdala to the paraventricular nucleus of the hypothalamus are involved in induction of yawning behavior due to emotional stress in rats.

As yawning is often observed in stressful or emotional situations such as tension and anxiety, this suggests that yawning can be considered to be an emotional behavior. However, the neural mechanisms underlying emotion-induced yawning remain unclear. It is well known that the hypothalamic paraventricular nucleus (PVN) is the most important brain structure for induction of yawning behavior. We previously showed that induction of yawning involves the central nucleus of the amygdala (CeA), as well as the PVN. Therefore, emotion-induced yawning could potentially be induced through activation of the direct/indirect neural pathways from the CeA to the PVN. Our present study used a combination of retrograde tracing (injection of Fluoro-Gold (FG) into the PVN) and c-Fos immunohistochemistry to examine the neural pathways that evoke emotion-induced yawning. We additionally performed lesion experiments on the CeA using ibotenic acid, a neurotoxin, to determine whether the CeA is involved in the induction of emotion-induced yawning. Emotional stress by fear conditioning induced yawning behavior, and induced expression of double-labeled cells for c-Fos and FG in the bed nucleus of the stria terminalis (BNST), but not in the CeA. Furthermore, the CeA lesions caused by ibotenic acid abolished the induction of emotion-induced yawning. These results suggest that a neural pathway from the CeA to the PVN via the BNST may be primarily involved in the induction of emotion-induced yawning behavior.

Oxytocin-induced yawning: sites of action in the brain and interaction with mesolimbic/mesocortical and incertohypothalamic dopaminergic neurons in male rats.

Oxytocin (80 ng) induces yawning when injected into the caudal part of the ventral tegmental area, the hippocampal ventral subiculum and the posteromedial nucleus of the amygdala of male rats. The behavioural response occurred concomitantly with an increase in the concentration of extracellular dopamine and its main metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) in the dialysate obtained from the shell of the nucleus accumbens and of the prelimbic medial prefrontal cortex by means of intracerebral microdialysis. Both oxytocin responses were significantly reduced by d(CH2)5Tyr(Me)²-Orn8-vasotocin, a selective oxytocin receptor antagonist, injected in the above brain areas 15 min before oxytocin. Similar results were obtained by activating central oxytocinergic neurons originating in the paraventricular nucleus of the hypothalamus and projecting to the ventral tegmental area, the hippocampus and the amygdala, with the dopamine agonist apomorphine given at a dose that induces yawning when injected into the paraventricular nucleus. Since oxytocin is considered a key regulator of emotional and social reward that enhances amygdala-dependent, socially reinforced learning and emotional empathy, mesolimbic and mesocortical dopamine neurons play a key role in motivation and reward, and yawning in mammals is considered a primitive, unconscious form of empathy, the present results support the hypothesis that oxytocinergic neurons originating in the paraventricular nucleus of the hypothalamus and projecting to the above brain areas and mesolimbic and mesocortical dopaminergic neurons participate in the complex neural circuits that play a role in the above mentioned functions.

Pandiculation: nature's way of maintaining the functional integrity of the myofascial system?

Pandiculation is the involuntary stretching of the soft tissues, which occurs in most animal species and is associated with transitions between cyclic biological behaviors, especially the sleep-wake rhythm (Walusinski, 2006). Yawning is considered a special case of pandiculation that affects the musculature of the mouth, respiratory system and upper spine (Baenninger, 1997). When, as often happens, yawning occurs simultaneously with pandiculation in other body regions (Bertolini and Gessa, 1981; Lehmann, 1979; Urba-Holmgren et al., 1977) the combined behavior is referred to as the stretch-yawning syndrome (SYS). SYS has been associated with the arousal function, as it seems to reset the central nervous system to the waking state after a period of sleep and prepare the animal to respond to environmental stimuli (Walusinski, 2006). This paper explores the hypothesis that the SYS might also have an auto-regulatory role regarding the locomotor system: to maintain the animal's ability to express coordinated and integrated movement by regularly restoring and resetting the structural and functional equilibrium of the myofascial system. It is now recognized that the myofascial system is integrative, linking body parts, as the force of a muscle is transmitted via the fascial structures well beyond the tendonous attachments of the muscle itself (Huijing and Jaspers, 2005). It is argued here that pandiculation might preserve the integrative role of the myofascial system by (a) developing and maintaining appropriate physiological fascial interconnections and (b) modulating the pre-stress state of the myofascial system by regularly activating the tonic musculature. The ideas presented here initially arose from clinical observations during the practice of a manual therapy called Muscular Repositioning (MR) (Bertolucci, 2008; Bertolucci and Kozasa, 2010a; Bertolucci, 2010b). These observations were supplemented by a review of the literature on the subject. A possible link between MR and SYS is presented: The neural reflexes characteristically evoked through MR are reminiscent of SYS, which both suggests that MR might stimulate parts of the SYS reaction, and also points to one of MR's possible mechanisms of action.

Complaints related to mandibular function impairment after closed treatment of fractures of the mandibular condyle.

This study analysed the relationship between complaints and mandibular function after closed treatment of fractures of the mandibular condyle in a prospective study. In a 1-year follow-up, complaints were assessed during physical examination and function was assessed using the mandibular function impairment questionnaire (MFIQ), scoring range 0-68. Data from 114 patients (41 women, 73 men), mean age 28.1 years (SD 13.3), were available. On average the MFIQ scores were low 3.4 (SD 7.3). Ten patients (9%) experienced pain and 45 (39%) patients had a MFIQ score > 0. Mean mouth opening was 51.9 mm (SD 8.4). Occlusion was perceived as moderate or poor by 24% of the patients. In the logistic regression analysis mandibular function impairment (MFIQ score > 0) was entered as a dependent variable. Risk factors for mandibular function impairment were: pain, perceived occlusion (moderate or poor), absolute difference between left and right horizontal movements and age. A protective factor was mouth opening. The results of this study show that complaints (i.e. pain, perceived occlusion, reduced mouth opening, difference between left and right lateral movements and increased age) are predictors of mandibular function impairment after closed treatment of fractures of the mandibular condyle.

Evaluation of Eustachian tube function with perfect sequences: technical realization and first clinical results.

The aim of this study was the introduction of a specific class of signals, the so-called perfect sequences (PSEQ), in a novel approach for sonotubometry of the Eustachian tube (ET). Sonotubometry using PSEQ stimuli was performed on 20 healthy subjects in order to gauge its potential for clinical applications. In a series of 320 measurements ET opening was probed, which was induced by dry and water swallowing, Toynbee maneuver, and yawning. All sonotubograms were analyzed with respect to their shape, increase of sound intensity, and opening duration. In 298/320 measurements (>93%) the subjects reported subjective ET openings. The evaluation of the recorded sonotubograms showed good detection of ET opening for the inducing maneuvers of swallowing (dry and water swallowing) and the Toynbee maneuver, with 90, 86, and 80% valid sonotubograms, respectively. Yawning led to only 40% valid sonotubograms. In total, 237/320 (~74%) sonotubograms were classified as valid. The evaluation of the sound level increase during ET openings showed that it was significantly higher in measurements with dry and water swallowing, as well as Toynbee maneuvers (mean 17.1, 19.0 and 17.2 dB, respectively), than with yawning (mean 10.17 dB; P < 0.0001). Nasal decongestion was found to have little influence on the results (P > 0.05). Sonotubometry using PSEQ stimuli is a novel sonotubometry methodology that provides valuable information regarding the auditory tube patency. By further technical refinements of the method, a diagnostic tool with high sensitivity and specificity could be developed.

Etiology, pathogenesis and treatment of habitual dislocations of the T.M. Joints [original work].

Definite treatment of any pathological condition, is based on the understanding of its correct pathogenesis and etiology. Without this basic understanding correct and lasting treatment is not possible. When there is no knowledge of exact pathogenesis and etiology, various theories and treatments are suggested by various workers. This is what exactly happened in the case of habitual dislocations of the T.M. Joints. This in term has happened because the dental surgeons and so called oral surgeons, never expanded their vision, beyond their restricted field of 20 deciduous teeth and 32 permanent teeth. Lack of understanding of basic physiological functions, of various tissues in the body and their effects on various systems as a whole was neglected. For this study four patients were selected from many, who could visit my clinic regularly and co-operate to follow all the instructions over a period of at least 5 years. The analysis of their symptoms and signs, had a different story to tell than what was described in the literature so far.

Historia clínica del paciente con cefalea: entrevista clinica. Anamnesis / Clinical history of the migraine patients: clinical interview and anamnesis

El acto de recogerla anamnesis de un paciente migrañoso reviste ciertas peculiaridades que posiblemente no se dan en otras situaciones clínicas: en primer lugar, la descripción que el paciente hará de sus síntomas será excepcionalmente buena, ya que su experiencia de sus -múltiples- crisis a lo largo del tiempo le permite hacer una relación sumamente detallada. En segundo lugar, la exploración clínica, siempre parte integrante de la anamnesis, tiene en esta situación un papel muy secundario. En tercer lugar, existe un riesgo de obtener respuestas sesgadas en función de las preguntas. El autor recoge en el presente trabajo una serie de recomendaciones y sugerencias fundamentales a la hora de "historiar" a un paciente de este tipo (AU)

Activity recognition in long-term electromyograms.

Long-term electromyography with portable recorders allows the study of muscle activity in the natural environment to investigate whether muscle overuse or oral habits may contribute to initiate or perpetuate a myoarthropathy of the masticatory system. At present, little is known about the behaviour of masticatory muscles over long time periods. The aim of this preliminary study was to define parameters which allow the automatic recognition of different types of oral activities from the electromyogram form. A programme with functional and parafunctional activities was performed by four volunteers (total of 333 functional and 82 parafunctional recordings). Electromyograms of the masseter and temporal muscles were recorded by means of a self-developed portable intelligent solid state recorder. Signal mean level (mw) and dynamics (dw) within a sliding window were determined. Temporal muscle recordings allowed better discrimination between function and simulated parafunction. The average of mw for clenching was 51.4 +/- 3.5% and for tooth grinding 21.2 +/- 2% of the peak electromyogram value at maximum voluntary clench. At 0.96 s sliding window duration, clenching, tooth grinding and chewing signals had maximum separation, using dw/mw as parameters (average: 0.16 +/- 0.01 for clenching, 0.39 +/- 0.01 for teeth grinding and 0.88 +/- 0.01 for chewing).

Bio-feedback and the yawning breath pattern in voice therapy: a clinical trial.

A breathing technique, or effective breath method is important for both singers and speakers for effective vocalization, and also useful for helping people with a voice problem. Here a diaphragm support breath pattern was used in voice therapy for patients with vocal nodules, recurrent laryngeal nerve paralysis, and incomplete glottal closure. Singing teachers use a technique, called the diaphragm breath support. This is called the yawning breath pattern (YBP) in our voice clinic and is used in teaching the patients with some kinds of voice disorder. In order to correct patients' breath pattern, an equipment system was designed to check their breath patterns conveniently in voice therapy practice. A respiratory kinematic sensor which connected to a TV monitor was attached to the patients' rib cage near the diaphragm, and by bio-feedback, patients could observe and adjust their breath pattern to the desired pattern during vocalization. In each of the 10 outpatient sessions, the patients performed for 20 to 30 min, and were instructed to practice at home for 3 or more times daily. The YBP method was applied to 91 patients, 17 males and 74 females, with ages ranging from 17 to 79 years. Of the 91 patients 41 had vocal nodules, 20 had recurrent laryngeal nerve paralysis and 30 had incomplete glottal closure associated with chronic laryngitis and sulcus vocalis. Most of the patients could master the YBP technique successfully. The higher the patients' ability to master the YBP was the better the results of both voice tests and subjective evaluation. The scientific background of the YBP method and its clinical effects in voice therapy was reviewed.