Phonon-Modulated Magnetic Interactions and Spin Tomonaga-Luttinger Liquid in the p-Orbital Antiferromagnet CsO2.

The magnetic response of antiferromagnetic CsO2, coming from the p-orbital S=1/2 spins of anionic O2(-) molecules, is followed by 133Cs nuclear magnetic resonance across the structural phase transition occurring at T(s1)=61 K on cooling. Above T(s1), where spins form a square magnetic lattice, we observe a huge, nonmonotonic temperature dependence of the exchange coupling originating from thermal librations of O2(-) molecules. Below T(s1), where antiferromagnetic spin chains are formed as a result of p-orbital ordering, we observe a spin Tomonaga-Luttinger-liquid behavior of spin dynamics. These two interesting phenomena, which provide rare simple manifestations of the coupling between spin, lattice, and orbital degrees of freedom, establish CsO2 as a model system for molecular solids.

Near infrared hyperspectral imaging as a sorting tool for deoxynivalenol reduction in wheat batches.

The present study aimed to evaluate the feasibility of using near-infrared hyperspectral imaging (NIR-HSI) and chemometrics for classification of individual wheat kernels according to their deoxynivalenol (DON) level. In total, 600 wheat kernels from samples naturally contaminated over the maximum EU level were collected, and the DON content in each individual wheat kernel was analyzed by UHPLC. Linear discriminant analysis (LDA) was employed for building classification models of DON using the EU maximum level as cut off level, and they were tested on balanced and imbalanced test sets. The results showed that the models presented a balanced accuracy of 0.71, that would allow to obtain safe batches from contaminated batches once the unsafe kernels had been rejected, but often more than 30% of the batch would be rejected. The work confirmed that NIR-HSI could be a feasible method for monitoring DON in individual kernels and removing highly contaminated kernels prior to food chain entry.

[Gastroschisis. Preterm elective cesarean and immediate primary closure: our experience]. / Gastrosquisis. Cesárea electiva pretérmino y cierre primario inmediato; nuestra experiencia.

PURPOSE: Our experience en treatment of gastroschisis using a protocol with elective preterm delivery by caesarean section at 34-35 weeks and immediate primary abdominal wall closure. METHODS: During a period of 18 month we treated 5 patients with gastroschisis using the following management pathway: Starting at 30th week of gestation, weekly ultrasound evaluation of fetal gut and pulmonary maturation with corticosteroids. Delivery by elective caesarean section between 34-35 weeks or earlier if evidence of bowel compromise was reported en ultrasound study. Immediate surgical correction after birth with primary closure was preformed under control of abdominal pressure. RESULTS: Mean gestational age of our patient was 33,94 weeks, and mean birth weight was 2154 gr. None of the cases present inflammatory peel and we found no difficulties for reduction of the gut at time of surgery. Two patients presented an intestinal malrotation. Extubation was preformed 36-48 hours after surgery. We started a trofic diet at 3,6 days and parental nutrition was retired after a mean period of 15,8 days. The mean time of hospital stay was 33,4 days. One patient with intestinal obstruction had a consideriously increased length of hospital stay of 74 days. CONCLUSIONS: A management pathway for gastroschisis with selective preterm delivery by caesarean section and immediate surgical treatment probably reduces the experience of inflammatory peel. This pathway permits a early initiation of oral feeding, reduces times of parenteral nutrition and need of central catheters, and shortens length of hospital stay.

[Prognostic factors and profile in traumatic brain injury in the paediatric age]. / Perfil y factores pronósticos en el traumatismo craneoencefálico en la edad pediátrica.

INTRODUCTION: Traumatic brain injury (TBI) is a common cause of death and disability in the paediatric population, although the literature on the Spanish population is scarce. From the perspective of early vulnerability, recent research findings suggest that early brain injury has worse sequelae and a higher risk of impact. AIMS: To analyse the intelligence profile, executive functions and behaviour, and examine the association between age at the time of the injury, severity of the TBI and environmental factors for cognitive and behavioural outcomes. PATIENTS AND METHODS: Seventy-one participants with moderate to severe TBI, from 6 to 16 years of age, were assessed with measures of intelligence (intelligence quotient), executive functions and behaviour. RESULTS: Children with TBI are at increased risk of disability in all aspects of intelligence, executive functions and behaviour. Children who suffered a traumatic brain injury in infancy and the preschool period had more overall effects on intelligence quotient and some aspects of the executive functions. CONCLUSIONS: Socioeconomic and cultural factors are the best predictors for intelligence quotient and behaviour. These findings contribute to a better understanding of the sequelae of TBI in children, which will help in rehabilitation planning and re-adaptation to functional life.

TITLE: Perfil y factores pronósticos en el traumatismo craneoencefálico en la edad pediátrica.Introducción. El traumatismo craneoencefálico (TCE) es una causa común de muerte y discapacidad en la población pediátrica, aunque la bibliografía en población española sea escasa. Desde la perspectiva de la vulnerabilidad temprana, los hallazgos de investigaciones recientes sugieren que la lesión cerebral temprana tiene peores secuelas y un mayor riesgo de impacto. Objetivos. Analizar el perfil de la inteligencia, las funciones ejecutivas y el comportamiento, y examinar la asociación de la edad a la lesión, la gravedad del TCE y los factores ambientales para los resultados cognitivos y conductuales. Pacientes y métodos. Setenta y un participantes con TCE moderado a grave, con edades entre 6 y 16 años, fueron evaluados con medidas de inteligencia (cociente intelectual), funciones ejecutivas y comportamiento. Resultados. Los niños con TCE tienen un mayor riesgo de discapacidad en todos los aspectos de inteligencia, funciones ejecutivas y comportamiento. Los niños que sufrieron una lesión cerebral traumática en la infancia y preescolar registraron más efectos globales en el cociente intelectual y algunos aspectos de las funciones ejecutivas. Conclusiones. Los factores socioeconómicos y culturales son los mejores predictores para el cociente intelectual y el comportamiento. Estos hallazgos contribuyen a una mejor comprensión de las secuelas de TCE en los niños para ayudar en la planificación de rehabilitación y la readaptación a la vida funcional.

Efficacy of a new parent and school-supported intervention after moderate and severe childhood traumatic brain injury. / Eficacia de una nueva intervencion de apoyo a padres y escuelas despues de un traumatismo craneoencefalico moderado o grave.

INTRODUCTION: Traumatic brain injury is a common cause of acquired disability during childhood. Early interventions focusing on parenting practices may prove effective at reducing negative child outcomes. AIM: To determine the efficacy of a new counselling program aimed at parents and schools compared to a control group. PATIENTS AND METHODS: The main study sample was obtained from a paediatric hospital. The final sample consisted of 42 children aged between 6 and 16 years old. RESULTS: Comparing with normative data, pre-post comparisons between groups showed a significant improvement in the parent group with respect to the control group. CONCLUSIONS: The superiority of the parental intervention group over those of the control group was not only statistically significant, but also clinically substantial and meaningful. The results of this study suggest that children with moderate to severe traumatic brain injury can benefit from an intensive supported family treatment.

TITLE: Eficacia de una nueva intervencion de apoyo a padres y escuelas despues de un traumatismo craneoencefalico moderado o grave.Introduccion. El traumatismo craneoencefalico es una causa habitual de discapacidad adquirida durante la infancia. Las intervenciones tempranas que se centran en la participacion de los padres pueden resultar efectivas para reducir las disfunciones del niño. Objetivo. Determinar la eficacia de un nuevo programa de asesoramiento dirigido a padres y escuelas en comparacion con un grupo control. Pacientes y metodos. La muestra principal del estudio se obtuvo de un hospital pediatrico. La muestra final consistio en 42 niños de 6 a 16 años. Resultados. Comparando con los datos normativos, las comparaciones pre y post intragrupos mostraron una mejora significativa en el grupo de intervencion parental con respecto al grupo control. Conclusiones. La superioridad del grupo de intervencion parental sobre el grupo control no solo fue estadisticamente significativa, sino tambien clinicamente sustancial y relevante. Los resultados del estudio sugieren que los niños con traumatismo craneoencefalico moderado o grave pueden beneficiarse de un tratamiento familiar intensivo de apoyo.

Anxiety and depression in women with breast cancer: Social and clinical determinants and influence of the social network and social support (DAMA cohort).

BACKGROUND: Anxiety and depression are the most prevalent mental health pathologies among women with breast cancer. Social, clinical and contextual variables may influence emotional stress among women with breast cancer. The aim of this work is to study anxiety and depression in a cohort of women diagnosed with breast cancer between 2003 and 2013 in Barcelona. We evaluate social and clinical determinants. METHODS: We performed a mixed cohort study (prospective and retrospective) using a convenience sample of women diagnosed with breast cancer. The information sources were the Hospital Anxiety and Depression questionnaire and hospital medical records. Dependent variables were anxiety and depression; independent variables were social class, age, employment status, tumour stage at diagnosis, time since diagnosis, social network and social support. We performed a descriptive analysis, a bivariate analysis, and a multivariate logistic regression analysis. RESULTS: A total of 1086 (48.6%) women had some degree of anxiety-related problem. As for depression. In the case of depression, 225 (15%) women had some degree of depression-related problem. Low emotional support and social isolation were clear risk factors for having more anxiety and depression. Low social class was also a risk factor, and age also played a role. DISCUSSION: Our results show that women long period of cancer survival have high prevalences of anxiety than depression, and this prevalence of anxiety is higher than the general population. In addition, we found inequalities between social classes and the isolation and social support are worse too in low social class.

[Current state of the attention deficit hyperactivity disorder approach in neuropediatrics]. / Estado actual del enfoque del trastorno por deficit de atencion/hiperactividad en neuropediatria.

AIM: To know the current state of the approach of attention deficit hyperactivity disorder (ADHD) in neuropediatricians. SUBJECTS AND METHODS: A telematic survey was carried out to collect preliminary information on the interest, difficulties in the management and treatment of ADHD to the 437 fellowship of the Neuropediactric Spanish Society (SENEP). RESULTS: Only 32.49% of the sent questionnaires were answered, with important geographic variability. 97.89% stated that 50% of their consultations were children with learning disabilities and ADHD. Regarding who started treatment for ADHD in their area, the majority answered that the neuropediatrician (57.97%), followed by the child psychiatrist (34.78%) and the primary care pediatrician (5.31%). The lack of a psycho-pedagogical study by the school (49.79%), followed by the lack of time in the consultation (29.11%), was cited as the greatest difficulty in the initial assessment of children with suspected ADHD. Concerning the difficulties in the follow-up, the biggest complaint was the lack of coordination between professionals, the school and parents. And, lastly, regarding the type of treatment use, most patients were on prolonged-release methylphenidate, a stable percentage using immediate release methylphenidate as a single or combined treatment, and in a lower range was the use of clonidine and atomoxetine, and an incipient use of lisdexamphetamine were observed. 80% of the patient showed adherence to pharmacological treatment after one year. CONCLUSIONS: It is necessary to advance in the training and continuous education of our neuropediatric specialists in ADHD and to homogenize the clinical practice and coordination with education system in the Spanish territory.

TITLE: Estado actual del enfoque del trastorno por deficit de atencion/hiperactividad en neuropediatria.Objetivo. Conocer el estado actual del enfoque del trastorno por deficit de atencion/hiperactividad (TDAH) entre los neuropediatras. Sujetos y metodos. Se realizo una encuesta telematica que recogia informacion preliminar sobre el interes, las dificultades en el manejo y el tratamiento del TDAH a los 437 socios de la Sociedad Española de Neurologia Pediatrica. Resultados. Respondio un 32,49% de los cuestionarios enviados, con una importante variabilidad geografica. El 97,89% afirmo que el 50% de sus consultas eran niños con trastornos de aprendizaje y TDAH. Respecto a quien iniciaba el tratamiento para el TDAH en su area, la mayoria contesto que el neuropediatra (57,97%), seguido del psiquiatra infantil (34,78%) y del pediatra de atencion primaria (5,31%). Respecto a las mayores dificultades para la valoracion inicial de los niños con sospecha de TDAH, se citaron la falta de un estudio psicopedagogico por parte de la escuela (49,79%), seguido de la falta de tiempo en la consulta (29,11%). Sobre las dificultades en el seguimiento, la mayor queja se produjo por la falta de coordinacion entre los profesionales, la escuela y los padres. Respecto a la medicacion, la mayoria de los pacientes se encontraba en tratamiento con algun tipo de metilfenidato de liberacion prolongada, un porcentaje estable utilizaba metilfenidato de liberacion inmediata como tratamiento unico o combinado, y se observo en un rango inferior el uso de clonidina y atomoxetina, y un incipiente uso de lisdexanfetamina. La adhesion al tratamiento farmacologico al año fue alrededor del 80%. Conclusiones. Es necesario avanzar en la capacitacion y educacion continua de nuestros especialistas neuropediatricos en el manejo del TDAH, y en homogeneizar la practica clinica y la coordinacion con educacion en el territorio español.

Contribution of the plasmalemma to Ca2+ homeostasis in hair cells.

Calcium influx through transduction channels and efflux via plasmalemmal Ca(2+)-ATPases (PMCAs) are known to contribute to calcium homeostasis and modulate sensory transduction in vertebrate hair cells. To examine the relative contributions of apical and basolateral pathways, we analyzed the calcium dynamics in solitary ciliated and deciliated guinea pig type I and type II vestibular hair cells. Whole-cell patch-clamp recordings demonstrated that these cells had resting potentials near -70 mV and could be depolarized by 10-20 mV by superfusion with high potassium. Fura-2 measurements indicated that ciliated type II cells and deciliated cells of either type had low basal [Ca(2+)](i), near approximately 90 nm, and superfusion with high potassium led to transient calcium increases that were diminished in the presence of Ca(2+) channel blockers. In contrast, measurements of type I ciliated cells, hair cells with large calyceal afferents, were associated with a higher basal [Ca(2+)](i) of approximately 170 nm. High-potassium superfusion of these cells induced a paradoxical decrease in [Ca(2+)](i) that was augmented in the presence of Ca(2+) channel blockers. Optical localization of dihydropyridine binding to the kinocilium suggests that they contain L-type calcium channels, and as a result apical calcium influx includes a contribution from voltage-dependent ion channels in addition to entry via transduction channels localized to the stereocilia. Eosin block of PMCA significantly altered both [Ca(2+)](i) baseline and transient responses only in ciliated cells suggesting that, in agreement with immunohistochemical studies, PMCA is primarily localized to the bundles.

Molecular diversity of voltage-gated sodium channel alpha subunits expressed in neuronal and non-neuronal excitable cells.

In order to investigate the role of molecular diversity of voltage-activated sodium channel alpha-subunits in excitability of neuronal and non-neuronal cells, we carried out patch-clamp recordings and single-cell RT-PCR on two different types of mammalian excitable cells i.e. hippocampal neurons and non-neuronal utricular epithelial hair cells. In each cell type, multiple different combinations of sodium channel alpha-subunits exist from cell to cell despite similar sodium current properties. The mRNA isoforms, Nav1.2 and Nav1.6, are the most frequently detected by single cell analysis in the two cell types while Nav1.3 and Nav1.7 are also moderately expressed in embryonic hippocampal neurons and in neonatal utricular hair cells respectively. By investigating the particular alternate splice isoforms of Nav1.6 occurring at the exon 18 of the mouse orthologue SCN8A, we revealed that this subunit co-exist in the two cell types under different alternative spliced isoforms. The expression of non-functional isoforms of Nav1.6 in utricular epithelial hair cells excludes the involvement of this subunit in supporting their excitability. Thus, from a functional point of view, the present results suggest that, at the single cell level, both neuronal and non-neuronal excitable cells expressed different and complex patterns of sodium channel gene transcripts but this diversity alone cannot explain the sodium current properties of these cell types.

Three-dimensional culture of newborn rat utricle using an extracellular matrix promotes formation of a cyst.

The vestibule is the end organ devoted to sensing of head movements in space. To function properly, its mechano-receptors require the presence of a unique apical extracellular medium, the endolymph. Numerous studies have elucidated the mechanisms involved in the production and homeostasis of this unique medium and the responses of sensory cells to stimulation. However, anatomical constraints have prevented direct and simultaneous studies of their relationships. The aim of this study was the development of an in vitro model that would allow concomitant investigations on maturation and physiological properties of both the hair cells and their endolymphatic compartment. A three-dimensional (3D) culture of newborn rat utricles using an extracellular matrix sustaining 3D cellular growth was developed during 3, 6, or 10 days in vitro (DIV). Using morphological and electrophysiological techniques, we describe the de novo formation of a cyst. It was composed of the sensory epithelium and non-sensory cells-canalar, dark and intermediate cells-that polarized so that their apical surface faced its lumen. During the time of culture, the utricular potential (UP) was steady (-1.1+/-5.0 mV) in oxygenated condition, while in anoxia, the UP significantly decreased to -8.4+/-1.0 mV at 8 DIV. Over the same period, the K+ concentration in the cyst increased up to 86.1+/-33.9 mM (versus 5.6+/-1.5 mM in the bath). These observations indicated that the mechanisms generating the UP and the K-secretory activity were functional at this stage. Concomitantly, the hair cells acquired mature and functional properties: the type 1 and type 2 phenotypes, a mean resting membrane potential of -68.1+/-4.6 mV and typical electrophysiological responses. This preparation provides a powerful means to simultaneous access the hair cells and their endolymphatic compartment, with the possibility to use multi-technical approaches to investigate their interdependent relationships.

[Retrospective diagnosis of congenital infection by cytomegalovirus in the case of one infant]. / Diagnóstico retrospectivo de infección congénita por citomegalovirus en un caso clínico infantil.

INTRODUCTION: 10-15% of asymptomatic congenital infections by cytomegalovirus (CMV) in the neonatal period develop persistent problems with varying degrees of severity, fundamentally involving neurological disorders, neurosensory hypoacusis and hypovision, which appear from the age of 6-9 months onwards, when a diagnosis is no longer possible. The PCR (polymerase chain reaction) technique can detect DNA of CMV in blood samples on filter paper used for screening hypothyroidism and metabolic pathologies that were kept from the neonatal period. CASE REPORT: A child aged 3 years and 8 months with delayed intrauterine growth, autism, mental retardation, microcephalus and neurosensory hypoacusis; periventricular calcifications, leukoencephalopathy and bilateral malformation of the temporal lobe; and a diagnosis of congenital CMV confirmed by detection of DNA by PCR in the blood sample on filter paper saved from the neonatal period. CONCLUSIONS: The retrospective study of congenital infection by CMV should be considered when faced with severity and varying association of delayed intrauterine growth, microcephalus, neurosensory hypoacusis, chorioretinitis, mental retardation, autism or other behavioural disorders, intracranial calcifications, encephaloclastic alterations, leukoencephalopathy, cortical dysplasia and malformations of the temporal lobe and the hippocampus. Since the filter papers from neonatal screening are not kept for ever, perhaps the idea of doing so ought to be considered, given the possibilities they offer for retrospective studies.

Transient increase in cytosolic free calcium evoked by repolarization in type I vestibular hair cells of rats.

Simultaneous whole-cell patch clamp and Fura-2 microfluorimetric recordings of membrane currents and intracellular free calcium concentration ([Ca2+]i) were made from type I vestibular hair cells isolated from cristae ampullares of adult rats. Cells held between -110 or -70 mV and depolarized up to -20 mV did not evoke any [Ca2+]i changes for any duration of the membrane depolarization (up to 3 s). Returning the membrane to repolarizing potential induced a transient [Ca2+]i increase. At the pulse break, an inward current was evoked. The [Ca2+]i increase and inward current amplitude were dependent on the duration and the amplitude of the previous depolarization. A liminar value of membrane depolarization of -55 +/- 3 mV (mean resting potential -62 +/- 7 mv) had to be applied to induce [Ca2+]i increase upon subsequent repolarization. [Ca2+]i response and inward current could not be evoked in calcium-free solution. Both responses were restored when calcium was added to the medium.

Analysis of temporal and spatial patterns of rat vestibular hair cell differentiation by tritiated thymidine radioautography.

The location in time and space of the terminal mitoses of type I and type II sensory hair cells (HCI and HCII) of the developing crista ampullaris in rat lateral semicircular canal and macula utriculi was determined by radioautographs of specimens exposed to tritiated thymidine from the 13th to the 20th day of gestation. Qualitative analysis and statistical treatment of the percentages of labeled HCI and HCII show that the terminal mitoses occur first in the macula utriculi with a maximum percentage of the 14th day of gestation, for the HCI, and on the 15th day of gestation, for the HCII. In the lateral crista, the maximum percentage of labeled HCI occurs on the 17th and 18th day of gestation and on the 19th day of gestation for the HCII. A spatial distribution of this labeling activity is also described: the older cells are located at the top of the crista and at the level of the striola of the macula utriculi while the younger cells are found at the bottom of the crista and on the sides of the utricle. A study of the vestibular receptors in the fetuses shows that synaptic contacts already exist on the 18th day of gestation in the macula utriculi at the level of the striola and on the 19th day at the top of the crista; the cells situated on the periphery are still immature. The first hair cells to undergo their terminal mitoses are, therefore, connected first. These results also suggest that the two types of cells are genetically programmed and that the HCI start functioning first during the development of the labyrinth.

Differentiation and maturation of the sensory hair bundles in the fetal and postnatal vestibular receptors of the mouse: a scanning electron microscopy study.

By means of scanning electron microscopy, the differentiation and maturation of sensory hair bundles have been studied in the ampullar cristae of the mouse during development from gestational day 13 (GD13) to postnatal day 10 (PD10). Two gradients of ciliary differentiation were demonstrated, one from the apex to the base and the other from the center to the periphery. The different hair bundles that appeared on the crista during the fetal period originated in an initial ciliary stage found in regions undergoing differentiation, differentiation, which was visible at the apex of the crista starting on GD14. This stage of ciliary development is gradually followed by a juvenile one at GD15. Starting on GD18, the maturation of hair bundles in the central apical area differed from that in the peripheral areas and prefigured the regional specialization of the crista found in the adult stage. In the discussion, we suggest that when the vestibular epithelial cells begin to exhibit ciliary differentiation, they are simultaneously contacted by nerve fibers.

The structural maturation of the stato-acoustic nerve in the cat.

The maturation of the stato-acoustic nerve in the cat was studied by light and electron microscopy from the fetal stage to the adult. Measurement of the outer diameter of the fibers and the study of the myelination process revealed that myelination begins earlier for the vestibular nerve than for the cochlear nerve: by the fifty-third day of gestation 64% of the vestibular fibres have already passed the promyelin stage whereas for the cochlear nerve this promyelin stage begins for the majority of fibers on the fifty-seventh gestation day. Afterward, maturation proceeds more rapidly for the cochlear nerve. In the case of both nerves, maturation is still incomplete at two months of age. Concerning the relationship between the thickness of the myelin sheath and the axoplasmic diameter, there is already a good correlation by the fifty-seventh day of gestation in the vestibular nerve, whereas it appears several days after birth in the cochlear nerve.

Selective retrograde labelling of vestibular efferent neurons with [3H]choline.

Following administration of [3H]choline in the lateral semicircular canal of the cat labyrinth, bidirectional axoplasmic transport [3H]choline and its derivatives was shown by radioautography in the vestibular system. Light-microscopic radioautographs exhibited various patterns of radioautographic labelling. First, a diffuse reaction was observed in vestibular nuclei representing anterograde-labelled, vestibular nerve endings. Second, a heavy labelling limited to perikarya was detected in efferent vestibular neurons and corresponded to retrograde transport. The anterograde migration of [3H]choline is known to be non-selective and is related to synthesis of phospholipids, non-diffusable molecules. In contrast, the retrograde perikaryal labelling seems highly selective and related to the cholinergic specificity of the transmitter. The selectivity of such labelling offers a further possibility of identifying cholinergic neurons and is additional evidence that cholinergic mechanisms are involved in the efferent vestibular control.

The efferent vestibular system in the cat: a horseradish peroxidase and fluorescent retrograde tracers study.

Neurons of the efferent vestibular system were investigated in the cat using retrograde axonal transport of horseradish peroxidase and fluorescent retrograde double labelling techniques. The number of efferent neurons was clearly higher than previously reported. A three dimensional reconstruction of the location of these neurons showed that they constitute a single group and did not give evidence of an eventual specialization based on neuron subpopulations. However, a study of cross-sectional areas of the horseradish peroxidase-labelled efferent neurons detected that the ipsilateral population contained a larger number of small neurons than the contralateral one. Double labelling by means of either 4',6-diamidino-2- phenylindol 2HCl in combination with horseradish peroxidase or Fast Blue in combination with Nuclear Yellow showed that 20% of efferent neurons project to both labyrinths. Such a high percentage raises the question of the role of these double-projecting cells and the specificity of their branching on vestibular receptors. This study expands previous work in the cat demonstrating that a much greater number of efferent neurons exists than had hitherto been assumed, among them 20% have both crossed and uncrossed projections.

Multiple voltage-dependent calcium currents in acutely isolated mouse vestibular neurons.

We investigated the presence of voltage-gated calcium currents in vestibular neurons acutely isolated from postnatal mice vestibular ganglions using the whole-cell patch-clamp technique. The neuronal origin of the recorded cells was confirmed by immunohistochemical detection of neurofilaments and calretinin. High and low voltage-activated calcium currents were recorded. High voltage-activated currents were present in all investigated neurons. Low voltage-activated currents were recorded in only a few large vestibular neurons. High and low voltage-activated currents were distinguished by their thresholds of activation and their ability to run-up during early recordings. Among high voltage-activated currents. L-, N- and P-type currents were identified by their sensitivity to, respectively, the dihydropyridines agonist Bay K 8644 (3 microM) and antagonist nitrendipine (3 microM), the co-conotoxin GVIA (3 microM) and the omega-agatoxin IVA at low concentration (50 nM). An inactivating current sensitive to 1 microM omega-agatoxin IVA with characteristics similar to those of the Q-type current was also recorded in vestibular neurons. When L-, N-, P-, Q-type barium currents were blocked, a residual high voltage-activated current defined by its resistance to saturating concentrations of all above blockers was detected. This residual current was completely blocked by 0.5 mM nickel and cadmium. Our results reveal that primary vestibular neurons express a variety of voltage-activated calcium currents with distinct physiological and pharmacological properties. This diversity could be related both with their functional synaptic characteristic, and with the intrinsic physiological properties of each class of vestibular afferents.

Detection of calbindin-D 28k mRNA in rat vestibular ganglion neurons by in situ hybridization.

The cellular distribution of calbindin-D 28k mRNA in the rat vestibular ganglion was examined by in situ hybridization. Using a [35S]cDNA probe a neuronal subpopulation expressing calbindin-D 28k mRNA with a strong intensity has been identified. These findings confirm the presence of a subclass of calbindin-immunoreactive neurons in the rat vestibular ganglion.

Dedifferentiation phenomena after denervation of mammalian adult vestibular receptors.

The effect of transecting the vestibular nerve on the vestibular sensory epithelium was studied in adult guinea-pigs. When denervation was complete, after fifteen days, the vestibular hair cells began to show morphological features of immaturity. After two months, the majority of hair cells showed a supporting cell phenotype. By four months, both hair cells and supporting cells had become morphologically similar to the epithelial cells which line the vestibular cavities. When denervation was incomplete, hair cells and supporting cells retained their normal phenotype. This, plus the dedifferentiation after complete denervation, indicates that the phenotypes of the hair cells and supporting cells are innervation-dependent.