Yawning in neurology: a review / Bocejo em neurologia: uma revisão

ABSTRACT Yawning is a stereotyped physiological behavior that can represent a sign or symptom of several conditions, such as stroke, parakinesia brachialis oscitans, parkinsonism, Parkinson's disease and epilepsy. More rarely, it can occur in patients with intracranial hypertension, brain tumor, multiple sclerosis, migraine, Chiari malformation type I, and amyotrophic lateral sclerosis. Drug-induced yawning is an uncommon clinical condition and yawning in patients with autism or schizophrenia is very rare. The aim of this review is to describe in detail the occurrence of the phenomenon in such conditions, and its' phenomenology and pathophysiology.

RESUMO Bocejo é um comportamento estereotipado fisiológico, o qual, contudo, pode representar um sinal ou sintoma de várias condições neurológicas, tais como, acidente vascular encefálico, incluindo a parakinesia brachial oscitans, parkinsonismo, doença de Parkinson, e epilepsia. Mais raramente, o bocejo pode ocorrer em pacientes com hipertensão intra-craniana, tumor cerebral, esclerose múltipla, migrânea, malformação de Chiari tipo I, e esclerose lateral amiotrófica. Bocejo-induzido por drogas representa outra condição clínica pouco comum. De outro modo, bocejo é muito raro em pacientes com autismo e esquizofrenia. O objetivo desta revisão foi descrever em detalhes a ocorrência deste fenômeno em tais condições, sua fenomenologia e fisiopatologia.

Prevalence of Operation Room-Related Syncope and Presyncope among Medical Students / 의학교육논단

Attending the operation room is an essential part of surgical clerkships. Syncope or presyncopal attacks in the operation room may negatively affect students' learning and career development. This study set out to identify the prevalence of syncope and presyncopal attacks in the operation room during medical students' surgical clerkships. Data from 420 medical students (303 men and 117 women) in their 3rd year of clerkship were collected between 2014 and 2017. An anonymous questionnaire was distributed to assess the prevalence and degree of syncope and presyncopal symptoms. A total of 27% of the respondents had experienced syncope or presyncopal symptoms, 49.6% of the female students and 18.8% of the male students (p < 0.001). Fifty students (43.5%) had been attending as observers at the time of the syncopal attack, while 65 students (56.5%) had been participating as assistants. Thirty-four students (29.6%) had recently eaten at the time of the syncopal attack, while 81 students (70.4%) had not recently eaten. Prodromal symptoms included the urge to sit down (21.2%), sweating (19.3%), nausea (16.9%), a feeling of warmth (13.3%), darkened vision (12.6%), yawning (11.7%), palpitation (11.0%), ear fullness (10.2%), black spots in one's vision (7.6%), and hyperventilation (7.1%). This study showed the prevalence of syncope and presyncopal symptoms in the operation room during surgical clerkships. For students' safety and effective clerkship learning, thorough proactive education on syncopal attacks is required.

Opioid Withdrawal Symptoms after Conversion to Oral Oxycodone/Naloxone in Advanced Cancer Patients Receiving Strong Opioids / 한국호스피스완화의료학회지

PURPOSE: Oral naloxone is combined with oxycodone to alleviate or prevent opioid-induced constipation in cancer pain patients. However, there is still concern that oral naloxone may precipitate opioid withdrawal symptoms in patients on opioids. We retrospectively investigated clinical characteristics of cancer patients who experienced opioid withdrawal symptoms. METHODS: We reviewed medical records of all patients who were prescribed with oral oxycodone/naloxone at a tertiary cancer center from January 1, 2012 through December 31, 2016. Eligible patients were screened based on demographics, opioid and naloxone dosages, clinical manifestation and pain intensity. RESULTS: Among a total of 1,641 patients, 10 patients were selected. Seven patients were male, and the average age was 68.1 years. The median dose of naloxone that induced withdrawal symptoms was 20 mg. Most common withdrawal symptom was shivering (seven patients) followed by cold sweating (five), and muscle twitching (five). Other symptoms included restlessness, fever, dizziness, and yawning. Pain was exacerbated from the median intensity of numeric rating scale (NRS) 3 to NRS 6. CONCLUSION: Opioid withdrawal symptoms may occur when switching to oral oxycodone/naloxone for cancer patients who have been treated with other strong opioids. A prospective, multicenter study on this issue should be conducted in future.

Temporomandibular joint dislocation: experiences from Zaria, Nigeria

OBJECTIVES: Dislocation of the temporomandibular joint may occur for various reasons. Although different invasive methods have been advocated for its treatment, this study highlights the value of non-invasive treatment options even in chronic cases in a resource-poor environment. MATERIALS AND METHODS: A seven-year retrospective analysis of all patients managed for temporomandibular joint dislocation in our department was undertaken. Patient demographics, risk factors associated with temporomandibular joint dislocation and treatment modalities were retrieved from patient records. RESULTS: In all, 26 patients were managed over a seven-year period. Males accounted for 62% of the patients, and yawning was the most frequent etiological factor. Conservative treatment methods were used successfully in 86.4% of the patients managed. Two (66.7%) of the three patients who needed surgical treatment developed complications, while only one (5.3%) patient who was managed conservatively developed complications. CONCLUSION: Temporomandibular joint dislocation appears to be associated with male sex, middle age, yawning, and low socio-economic status, although these observed relationships were not statistically significant. Non-invasive methods remain an effective treatment option in this environment in view of the low socio-economic status of the patients affected.

Tecleo e inducción visual del bostezo en pacientes ansiosos: La Lisa, Ciudad de La Habana, 2008-2009 / Tapping and yawning visual induction in anxious patients: La Lisa, Ciudad de La Habana, 2008-2009

Debido a la vida tan dinámica de hoy día, y a factores de índole ambiental, genético y social, la ansiedad ha pasado a ocupar uno de los lugares principales dentro de los trastornos psicológicos, no solo en Cuba, sino a nivel mundial. Actualmente el diagnóstico y su evaluación se basan en pruebas subjetivas fundamentalmente a través de test. Motivados por los elementos antes expuestos se decidió investigar con el objetivo de hacer una evaluación preliminar de un software encaminado a medir variables, mediante la prueba del tecleo (mouse finger tapping) e inducción del bostezo, que aporten elementos objetivos para la valoración de pacientes con trastornos de ansiedad. Se realizó un estudio descriptivo transversal sobre la observación de las pruebas realizadas en pacientes atendidos en el Centro Comunitario de Salud Mental La Lisa, Ciudad Habana, de enero de 2008 a septiembre de 2009. La población de estudio estuvo conformada por 90 sujetos, y fueron evaluados mediante la prueba de Scam. Se tomaron datos de la historia clínica individual, y posteriormente se procesaron y representaron en tablas arribando a resultados. Se concluyó que las pruebas de tecleo e inducción visual del bostezo, permiten diferenciar de manera eficiente los grupos de sujetos estudiados.

Due to the agitated dynamic of the current life and many other environmental, genetic and social factors, the anxiety has passed to occupy one of the main places among the psychological dysfunctions, not only in Cuba, but at the world level. Nowadays the diagnosis and evaluation of this illness are based fundamentally on subjective tests. Motivated by the previously exposed elements, we decided to carry out a research with the objective of preliminary evaluating a software made for measuring variables, by means of the tapping test (mouse finger tapping) and yawn induction that renders objective elements in the evaluation of patients with anxiety dysfunctions. We carried out a cross-sectional descriptive study on the observation of the tests made in patients attended at the Communitarian Center of Mental Health La Lisa, Ciudad de La Habana, from january 2007 to september 2008. The studied population was formed by 90 subjects that were evaluated by means of the Scam test. We collected data from the individual clinical history. They were processed and shown in tables and charts arriving to conclusions. We concluded that the tapping test and the test of yawning visual induction allow differentiating, in an efficient way, the groups of studied patients.

El bostezo como signo en la enfermedad de Parkinson / Yawn as a sign in Parkinson's disease

Se computaron los bostezos que produjeron 30 sujetos sanos y 30 sujetos con la enfermedad de Parkinson, con el objetivo de evidenciar la utilidad que pueden tener como signo para la evaluación de estos pacientes. Los bostezos fueron inducidos mediante video durante 30 min, según métodos de los autores. Al comparar los sujetos sanos, con los pacientes privados de medicamentos durante 12 h, se observó en estos últimos una disminución significativa en la frecuencia de aparición del bostezo (sanos 15,086-Parkinson 1,700). En la comparación del grupo de pacientes en 2 momentos: medicación suspendida y después de 1½ h de restituido el tratamiento, se apreció un incremento significativo de los bostezos en los pacientes medicados (sin 1,700-con L-dopa 7,093). De esos resultados se infiere que la observación de esta conducta puede orientar sobre los efectos del tratamiento que se esté empleando.

The yawns produced by 30 sound individuals and 30 subjects with Parkinson's disease were computed in order to evidence the usefulness they may have as a sign for the evaluation of these patients. The yawns were induced by video for 30 minutes, according to the authors' methods. On comparing the sound subjects with the patients deprived from drugs during 12 hours, it was observed in the latter a significant reduction in the frequency of appearance of yawns (sound 15.086-Parkinson 1.700). On comparing the groups of patients at 2 moments: suspended medication and 1 ½ hour after re-establishing the treatment, it was observed a marked rise of the yawns in the medicated patients (without 1.700-with L-dopa 7.093). From these results, it was inferred that the observation of this behaviour may explain the effects of the treatment being used.

Behavioral and neuropharmacological evidence that serotonin crosses the blood-brain barrier in Coturnix japonica (Galliformes; Aves)

This study was carried out aiming to reach behavioral and neuropharmacological evidence of the permeability of the blood-brain barrier (BBB) to serotonin systemically administered in quails. Serotonin injected by a parenteral route (250-1000 æg.kg-1, sc) elicited a sequence of behavioral events concerned with a sleeping-like state. Sleeping-like behaviors began with feather bristling, rapid oral movements, blinking and finally crouching and closure of the eyes. Previous administration of 5-HT2C antagonist, LY53857 (3 mg.kg-1, sc) reduced the episodes of feather bristling and rapid oral movements significantly but without altering the frequency of blinking and closure of the eyes. Treatment with the 5-HT2A/2C antagonist, ketanserin (3 mg.kg-1, sc) did not affect any of the responses evoked by the serotonin. Quipazine (5 mg.kg-1, sc) a 5-HT2A/2C/3 agonist induced intense hypomotility, long periods of yawning-like and sleeping-like states. Previous ketanserin suppressed gaping responses and reduced hypomotility, rapid oral movements and bristling but was ineffective for remaining responses induced by quipazine. Results showed that unlike mammals, serotonin permeates the BBB and activates hypnogenic mechanisms in quails. Studies using serotoninergic agonist and antagonists have disclosed that among the actions of the serotonin, feather bristling, rapid oral movements and yawning-like state originated from activation of 5-HT2 receptors while blinking and closure of the eyes possibly require other subtypes of receptors.

Este estudo foi desenvolvido objetivando ampliar as evidências comportamentais e neurofarmacológicas da permeabilidade da barreira hematoencefálica (BHE) à serotonina administrada sistemicamente em codornas. A serotonina injetada por via parenteral (250-1000 æg.kg-1, sc) produziu uma seqüência de eventos relacionados com um estado semelhante ao sono. Comportamentos semelhantes ao sono começaram com o eriçamento das penas, movimentos orais rápidos, piscadelas e finalmente agachamento e fechamento dos olhos. A administração prévia do antagonista do receptor 5-HT2C, LY53857 (3 mg.kg-1, sc) reduziu significativamente os episódios de eriçamento das penas e movimentos orais rápidos, mas não alterou a freqüência de piscadelas e fechamento dos olhos. Tratamento com o antagonista do receptor 5-HT2A/2C, quetanserina (3 mg.kg-1, sc) não afetou nenhuma das respostas evocadas pela serotonina. A quipazina (5 mg.kg-1, sc), um agonista dos receptores 5-HT2A/2C/3, induziu intensa hipomotilidade e longos períodos de comportamentos semelhantes ao bocejo e ao sono. O tratamento prévio com quetanserina suprimiu as reações de bocejo e reduziu a hipomotilidade, os movimentos orais rápidos e as piscadelas, mas foi sem efeito para as demais respostas induzidas pela quipazina. Os resultados mostraram que, diferentemente dos mamíferos, a serotonina atravessa a BHE e ativa mecanismos hipnogênicos em codornas. Estudos com agonistas serotoninérgicos e antagonistas revelaram que, entre as ações da serotonina, o eriçamento das penas, os movimentos orais rápidos e o comportamento semelhante ao bocejo foram originados pela ativação de receptores 5-HT2, enquanto o piscar e o fechamento dos olhos possivelmente requereu outros subtipos de receptores.

Relación de los potenciales evocados auditivos de media latencia y bostezo / Relation between the middle latency auditory evoked potentials and yawn

Se observó qué cambios produciría el bostezo en los potenciales evocados auditivos de media latencia y así conocer más sobre la generación de esa conducta. Para llevar a cabo esto se registraron los potenciales evocados auditivos de media latencia de 10 hombres, adultos sanos, en las condiciones de control e inmediatamente antes y después del bostezo. Los resultados obtenidos mostraron un incremento significativo de la amplitud de la onda Pa después del bostezo. Esto permitió concluir la participación decisiva del tronco encefálico en la generación del bostezo y su naturaleza endógena

Open Lock of the Jaw on Induction of Anesthesia: A case report / 대한마취과학회지

The temporomandibular joint can be dislocated during anesthesia as a result of excessive oral opening and direct laryngoscope handling. Occasionally, yawning can be observed during the induction of anesthesia with propofol. The forceful and voluntary yawning after a propofol injection can lead to a dislocation of the temporomandibular joint. We report a case of an anterior dislocation of the temporomandibular joint upon induction with propofol, which caused difficulties in mask ventilation and endotracheal intubation. Although intubation had been carried out successfully in this case, an unanticipated difficult airway can be confronted at anytime. Therefore, anesthesiologists should be aware of the management of a difficult airway and practice various methods according to a difficult airway algorithm.

A Case of Glossopharyngeal Neuralgia after Tonsillectomy / 대한이비인후과학회지

Tonsillectomy is one of the most common procedures performed by an otorhinolaryngologist. Postoperative hemorrhage and dehydration are two of the most common complications, but glossopharyngeal neuralgia is an unusual complication encountered in tonsillectomy. Glossopharyngeal neuralgia is characterized by paroxysms of ipsilateral and severe lancinating pain occurring in the distribution of the nerve. The pain may be spontaneous or precipitated by a variety of actions that stimulate the region supplied by the glossopharyngeal nerve namely yawning, coughing, swallowing and talking. The proximity between the glossopharyngeal nerve and the tonsillar fossa suggests that dissection in the correct surgical plane during tonsillectomy is important for avoiding injury to the glossopharyngeal nerve. Glossopharyngeal neuralgia after tonsillectomy is induced by intraoperative cauterization, nerve compression or iatrogenic trauma. Management of glossopharyngeal neuralgia induced by tonsillectomy should be given a trial of anti-convulsant medication like carbamazepine or glossopharyngeal nerve resection. A case of glossopharyngeal neuralgia caused by tonsillectomy was experienced by a 29-year-old man, and this case was reported and its aetiology was discussed.

Drug Induced Cerebral Proerectile Effect in Anesthethetized Rats / 대한남성과학회지

PURPOSE: To examine the centrally elicited erectile effects of alpha-MSH, oxytocin, prostagladin E1, and anabolic steroids after intracerebroventricular administration. MATERIALS AND METHODS: We used anesthetized male Sprague-Dawley rats. After intracerebroventricular administration of normal saline (NS), alpha-melanocyte stimulating hormone (alpha-MSH), oxytocin acetate (OT), prostaglandin E1 (PGE1), methylprednisolone (MP), testosterone enanthate (TE) or 17beta-estradiol (E2) under stereotaxis, the intracavernosal pressure (ICP), systolic femoral artery pressure (FAP), heart rate (HR), time to first response, duration, and number of erectile responses and adverse reactions were evaluated for 60 minutes. To show whether erections were centrally elicited, the above criteria were re-evaluated after a bilateral pelvic neurotomy and bilateral orchiectomy. RESULTS: A cerebral proerectile effect was elicited only by alpha-MSH and OT with no significant changes of FAP or HR. With PGE1, significant changes in FAP and HR were observed. The ICP/FAP ratio was highest (0.49 0.03) with alpha-MSH. The mean time latency was shortest with OT (20.6 5.6 min). The mean duration was longest in alpha-MSH (11.6 8.7 min). The number of responses was highest with OT (3.6 0.7). Adverse reactions, such as stretching, yawning and ejaculation, were simultaneously observed during increases in ICP. In the cases of a bilateral pelvic neurotomy or bilateral orchiectomy, these elicited erectile responses disappeared. CONCLUSIONS: alpha-MSH had the most potent proerectile effect compared to OT and PGE1 as assessed by highest intracavernosal pressure as well as duration of erectile response. The results suggest that testosterone and the pelvic nerve were essential for the central proerectile response.

Cerebral Proerectile Effect of Apomorphine and Vasoactive Agents in Anesthetized Rats / 대한비뇨기과학회지

PURPOSE: To establish central control of a penile erection, the centrally elicited erectile effects of apomorphine hydrochloride and various vasoactive agents were investigated after intracerebroventricular administration. MATERIALS AND METHODS: Anesthetized male Sprague-Dawley rats were used for the study. After intracerebroventricular administration of normal saline(NS), apomorphine hydrochloride(AH), prostaglandin E1(PGE1), sodium nitroprusside(SNP), phenylephrine hydrochloride(PE) and phentolamine(PT) under a stereotaxic setting, the intracavernosal pressure(ICP), systolic femoral artery pressure(FAP), heart rate(HR), time to first response, duration and number of erectile response and adverse reactions were evaluated for 60 minutes. To show if the centrally elicited erection by agents in native setting were effective, the above criteria were re-evaluated after a bilateral pelvic neurotomy and bilateral orchiectomy. RESULTS:Cerebral proerectile effects were elicited by AH with no significant changes in the FAP and HR, but with PGE1, SNP, PE and PT significant changes in both the FAP and HR were observed. The ICP/FAP ratio was highest with SNP at 0.75+/-0.08. The mean time to first response was shortest with AH at 18.1+/-5.1min. The mean duration was longest with AH at 39.4+/-10.9min. The number of responses was highest with AH at 2.7+/-1.1. Adverse reactions, such as stretching, yawning and ejaculation, were simultaneously observed during increases in the ICP. In the case of a bilateral pelvic neurotomy or bilateral orchiectomy, these elicited erectile responses disappeared. CONCLUSIONS: Vasoactive agents, such as SNP, PGE1 and PE, had a cerebral proerectile effect, but AH showed more an evidently potent proerectile effect in the aspects of ICP, time to first response and duration of erectile response. Testosterone and the pelvic nerve are suggested to be essential for a central proerectile response.

Endoscopic Transnasal Vidian Neurectomy for Intractable Allergic Rhinitis / 신경정신의학

We hereupon present a case of injured temporomandibular joint (TMJ) associated with fluoxetine monotherapy-induced repeated yawning. Further information is needed regarding the relationship between fluoxetine administration and clinically significant yawning. Clinicians should be more careful to listen to their patients when they describe unexpected reactions to medications.

Bostezo y epilepsia del lobulo temporal / Yawning and temporal lobe epilepsy

Temporal lobe epilepsy is a partial epileptic disorder in which mesial structures are responsible for the principal ictal symptoms. Its characteristic feature is the recurrence of simple and complex partial seizures, associated with postictal confusion and amnesia of the event. The facilitating effect of NREM sleep on the propagation of the seizure, as well as the sleep abnormalities provoked by epilepsy were evident in our two patients. Yawning is a physiological reflex induced by arousal and drowsiness and may appear in different neurological conditions. Its relation with epilepsy of limbic origin has been rarely reported. We describe in a 95 year old male patient, the occurrence of yawning followed by complex partial seizure during a state of drowsiness. His EEG showed independent bilateral interictal foci of temporal sharp waves and after being medicated with carbamazepine 400 mg/day, the episode did not recur. Another patient, a 17 year old female, displayed complex partial seizures and secondarily generalized seizures with yawning during the posictal period, after naps. The EEG was normal and her polysomnography showed bilateral synchronous temporal spikes and slow waves with secondarily generalization during stage 2 of NREM sleep that produce paroxysmal microarousals and increased stages 1 and 2 of NREM sleep and REM sleep diminished. After being medicated with divalproex sodium 750 mg/day, she suffered no further seizures. Temporal lobe epilepsy, sleep-wake cycles and yawning seem not only to share the same anatomic structures but also the same neurochemical mechanisms. The fact that endogenous opiods are considered as part of a protective system that stop and prevent seizures may allow us to postulate that yawning would be the expression of the endogenous opiods induced mechanisms that stop and prevent the recurrence of the temporal lobe epilepsy. Another hypothesis may be that this is only a particular form of temporal lobe epilepsy

Bostezo / Yawning

El bostezo es un reflejo normal desencadenado por el despertar, el adormecimiento, el aburrimiento, el hambre y los conflictos emocionales, estando también asociado a diversas enfermedades neurológicas y abuso de drogas. Su amplia representación en la escala filogenética de los vertebrados, así también como la presencia en el hombre en edades tan tempranas como las 12 semanas de vida intrauterina, condujo a investigar los mecanismos comunes anátomo-bioquímicos involucrados en este proceso. La demostración que el bostezo no se genera en respuesta a niveles altos de CO 2 o bajos de O 2 en sangre, desechó la hipótesis metabólica ampliamente difundida. Su estrecha relación con el ciclo sueño-vigilia, especialmente en los momentos previos al dormir y siguiendo al despertar, está vinculado a cambios de estado y de actividad. El único componente de este reflejo que se encuentra sólo en el hombre, es que puede contagiarse. Por lo tanto, se lo considera como constituyente del mecanismo adaptativo de respuesta al stress, formando parte del reflejo de vigilancia, el cual ha adquirido un valor paralingüístico con la evolución, destinado a la protección y cohesión social. Las estructuras anatómicas y los sistemas neuroquímicos comunes intervinientes en el bostezo, el ciclo sueño-vigilia y la epilepsia del lóbulo temporal, nos permitirían postular que el bostezo sería la expresión de un sistema de protección inducido por los opiáceos endógenos, que actuarían en la inhibición y prevención de las crisis epilépticas del lóbulo temporal.

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.

Can Yawning Be Used as an Indicator of Induction of Anesthesia? / 대한마취과학회지

BACKGROUND: We can usually see the yawning at induction of anesthesia, however, it has not been studied as such an indicator of anesthesia. The yawning is one means of changing arousal level, and a sign or marker that such a change is occurring, although its functions are not well understood. The purpose of the present study was to evaluate the yawning whether it could be used as an indicator of induction of anesthesia, using its property as a marker of changed arousal level. METHODS: In 60 adult patients, group 1 was done propofol target controlled infusion (TCI) with Stelpump software, while group 2 was done thiopental TCI similarly. Clinical indicators of induction of anesthesia were measured as follows: loss of verbal control (LOV), loss of eyelash reflex (LOE), the yawning. In addition, the occurrence of apnea (OOA) were measured, too. We assessed the hypnosis levels of indicators of induction of anesthesia including the yawning and demonstrate their effect site concentrations and elapsed time. Furthermore, we compared the incidences of yawning and apnea between both groups. RESULTS: Clinical indicators of induction occurred in the order of LOV > LOE > the yawning >> OOA in both groups. With respect to BIS, the yawning showed the lowest BIS and the highest effect site concentrations except OOA in both groups. The incidence of the yawning in group 2 was higher than in group 1 (about 82 vs 63%). On the contrary, the incidence of apnea in group 1 was higher than in group 2 (about 79 vs 53%). CONCLUSIONS: As far as the yawning could be shown, we could observe, it approximated most closely to their clinical impression of the 'true' induction in terms of the hypnosis level and its effect site concentration.

Dosis óptimas para la inducción del bostezo con apomorfina en el humano sano / Optimal doses for the induction of vawning with apomorphine in the healthy human

Se estudió el efecto de la administración subcutánea de 4, 6, 8, 10, 12, 14 m g de apo-morfina en 16 hombres voluntarios sanos, con el objetivo de encontrar las dosis óptimas para la inducción del bostezo en el humano sano. Se dividieron en 2 subgrupos de 8 para administrarles a cada grupo sólo 3 dosis. A todos se les administró suero fisiológico para estudiar el bostezo espontáneo (situación control). Los resultados demuestran que el rango de 8 a 10 m g es el más adecuado para la inducción del bostezo. Las dosis inferiores tuvieron poco efecto inductor, las dosis superiores produjeron efectos indeseables

Efecto de la privación de agua sobre el bostezo espontáneo en la rata / Effect of water deprivation on spontaneous yawing in rats

Con el objetivo de comprobar si la hormona arginina-vasopresina (AVP) tiene alguna influencia sobre el bostezo espontáneo en ratas adultas de la cepa Wistar se efectuaron 2 series experimentales: a) estudio del efecto de la privación de agua (WD) sobre el bostezo y b) estudio del efecto de la WD sobre el bostezo en animales en ayuno durante 96 h (el ayuno suprime el bostezo espontáneo a las 24 h en los animales estudiados). Se observó que la WD no afecta de manera significativa el bostezo en los animales con alimentación normal. En los animales en ayuno se observó la supresión del bostezo en el grupo control (ayuno y agua ad libitum) mientras que en el grupo experimental (WD y ayuno) se evitó la supresión que sobre el bostezo provoca el ayuno. Se infiere de estos resultados que la AVP participa en la regulación del bostezo en las condiciones estudiadas; la forma en que lo hace queda fuera del alcance de este estudio