HERMES: Towards an Integrated Toolbox to Characterize Functional and Effective Brain Connectivity

The analysis of the interdependence between time series has become an important field of research in the last years, mainly as a result of advances in the characterization of dynamical systems from the signals they produce, the introduction of concepts such as generalized and phase synchronization and the application of information theory to time series analysis. In neurophysiology, different analytical tools stemming from these concepts have added to the ‘traditional’ set of linear methods, which includes the cross-correlation and the coherency function in the time and frequency domain, respectively, or more elaborated tools such as Granger Causality. This increase in the number of approaches to tackle the existence of functional (FC) or effective connectivity (EC) between two (or among many) neural networks, along with the mathematical complexity of the corresponding time series analysis tools, makes it desirable to arrange them into a unified-easy-to-use software package. The goal is to allow neuroscientists, neurophysiologists and researchers from related fields to easily access and make use of these analysis methods from a single integrated toolbox. Here we present HERMES (http://hermes.ctb.upm.es), a toolbox for the Matlab® environment (The Mathworks, Inc), which is designed to study functional and effective brain connectivity from neurophysiological data such as multivariate EEG and/or MEG records. It includes also visualization tools and statistical methods to address the problem of multiple comparisons. We believe that this toolbox will be very helpful to all the researchers working in the emerging field of brain connectivity analysis.     

Automatic Apnea Identification by Transformation of the Cepstral Domain

A new approach based on the transformation of the Cepstral domain is developed on this work. This approach reaches an automatic diagnosis for the syndrome of obstructive sleep apnea that includes a specific block for the removal of electrocardiogram (ECG) artifacts and the R wave detection. The system is modeled by a transformation of the Cepstral domain sequence using hidden Markov model (HMM). The final decision is done with two different approaches: one based on HMM as a classifier and a second one based on support vector machines classification and a parameterization based on the transformation of HMM by a kernel. The later approach reached results up to 99.23 %, using all test samples from Physionet Apnea-ECG Database.     

Use of antidepressants in the treatment of depression in Asia: Guidelines,clinical evidence,and experience revisited

Major depressive disorder is prevalent worldwide, and only about half of those affected will experience no further episodes or symptoms. Additionally, depressive symptoms can be challenging to identify, with many patients going undiagnosed despite a wide variety of available treatment options. Antidepressants are the cornerstone of depression treatment; however, a large number of factors must be considered in selecting the treatment best suited to the individual. To help support physicians in this process, international and national treatment guidelines have been developed. This review evaluates the current use of antidepressant treatment for major depressive disorder in six Asian countries (China, Korea, Malaysia, Philippines, Taiwan, and Thailand). No remarkable differences were noted between Asian and international treatment guidelines or among those from within Asia as these are adapted from western guidelines, although there were some local variations. Importantly, a shortage of evidence‐based information at a country level is the primary problem in developing guidelines appropriate for Asia, so most of the guidelines are consensus opinions derived from western research data utilized in western guidelines. Treatment guidelines need to evolve from being consensus based to evidence based when evidence is available, taking into consideration cost/effectiveness or cost/benefit with an evidence‐based approach that more accurately reflects clinical experience as well as the attributes of each antidepressant. In everyday practice, physicians must tailor their treatment to the patient's clinical needs while considering associated external factors; better tools are needed to help them reach the best possible prescribing decisions which are of maximum benefit to patients.     

Two types of periglomerular cells in the olfactory bulb of the macaque monkey (Macaca fascicularis)

The olfactory bulb (OB) of mammals is the brain region that receives the sensory information coming from the olfactory epithelium. The entrance of the olfactory information occurs in spherical structures of neuropil named olfactory glomeruli and is modulated by a population of interneurons known as periglomerular cells (PG). It has been demonstrated that there are two types of PG in the OB of some macrosmatic mammals, including rats and mice. Type 1 PG (PG-1) receive synapses from the olfactory nerve, whereas type 2 PG (PG-2) do not receive synapses from the olfactory axons. To date, the presence of the two types of PG has not been investigated in microsmatic mammals. In this context, we analyze the presence of PG-1 and PG-2 in the OB of the long-tailed macaque (Macaca fascicularis). For that, we used the enzyme tyrosine hydroxylase, the neuronal isoform of the enzyme nitric oxide synthase and the calcium-binding proteins calbindin D-28k and calretinin as neurochemical markers. Our results demonstrate that the OB of the macaque contains PG-1 and PG-2. A subpopulation of PG-1 expresses tyrosine hydroxylase and another expresses the neuronal isoform of nitric oxide synthase. In addition, a subpopulation of PG-2 expresses calbindin D-28k and another expresses calretinin. Double immunofluorescence demonstrates that there is no colocalization of two markers in the same PG. These results mimic those found in macrosmatic animals. The presence of two types of PG in the glomerular circuits seems to be a key principle for the organization of the OB of mammals.     

Mapping of alpha-neo-endorphin- and neurokinin B-immunoreactivity in the human brainstem

We have studied the distribution of alpha-neo-endorphin- or neurokinin B-immunoreactive fibres and cell bodies in the adult human brainstem with no prior history of neurological or psychiatric disease. A low density of alpha-neo-endorphin-immunoreactive cell bodies was only observed in the medullary central gray matter and in the spinal trigeminal nucleus (gelatinosa part). Alpha-neo-endorphin-immunoreactive fibres were moderately distributed throughout the human brainstem. A high density of alpha-neo-endorphin-immunoreactive fibres was found only in the solitary nucleus (caudal part), in the spinal trigeminal nucleus (caudal part), and in the gelatinosa part of the latter nucleus. Neurokinin B-immunoreactive cell bodies (low density) were found in the periventricular central gray matter, the reticular formation of the pons and in the superior colliculus. The distribution of the neurokinin-immunoreactive fibres was restricted. In general, for both neuropeptides the density of the immunoreactive fibres was low. In the human brainstem, the proenkephalin system was more widely distributed than the prodynorphin system, and the preprotachykinin A system (neurokinin A) was more widely distributed than the preprotachykinin B system (neurokinin B).     

Immunohistochemical Detection of the Putative Mechanoproteins ASIC2 and TRPV4 in Avian Herbst Sensory Corpuscles

The avian Herbst corpuscles are the equivalent of the Pacinian corpuscles in mammals, and detect vibration and the movement of joints and feathers. Therefore, they can be regarded as rapidly adapting low‐threshold mechanoreceptors. In recent years, it has been establish that some ion channels are involved in mechanosensation and are present in both mechanosensory neurons and mechanoreceptors. Here we have used immunohistochemistry to localize some putative mechanoproteins in the Herbst corpuscles from the rictus of Columba livia. The proteins investigated were the subunits of the epithelial Na⁺ channel (ENaC), the transient‐receptor potential vanilloid 4 (TRPV4), and the acid‐sensing ion channel 2 (ASIC2). Immunoreactivity for ENaC subunits was never found in Herbst corpuscles, while the axon expressed ASIC2 and TRPV4 immunoreactivity. Moreover, TRPV4 was also detected in the cell forming the inner core. The present results demonstrate for the first time the occurrence of mechanoproteins in avian low‐threshold mechanoreceptors and provide further evidence for a possible role of the ion channels in mechanosensation. Anat Rec, 2013. © 2012 Wiley Periodicals, Inc.     

Effects of Head and Neck Inclination on Bilateral Sternocleidomastoid EMG Activity in Healthy Subjects and in Patients with Myogenic Cranio-Cervical-Mandibular Dysfunction

This study was conducted in order to determine the effect of head and neck position on bilateral electromyographic (EMG) activity of the sternocleidomastoid muscles. The study was performed on 16 patients with myogenic cranio-cervical-mandibular dysfunction (CMD) and 16 healthy subjects. EMG recordings at rest and during swallowing of saliva and maximal voluntary clenching were performed by placing surface electrodes on the right and left sternocleidomastoid muscles. EMG activity was recorded in the left lateral decubitus position, in a darkened room and with the individual's eyes closed, under the following experimental conditions: 1. Head, neck, and body horizontally aligned; 2. Head and neck upwardly inclined with respect to the body, simulating the effect of a thick pillow, 3. Head and neck downwardly inclined with respect to the body, simulating the effect of a thin pillow. Variation of head and neck positions was determined by measuring the distance from the angle of neck and shoulder and the apex of the shoulder (SND = shoulder—neck distance) of each individual. Then, head and neck were forward or downwardly inclined with respect to the body at one-third of SND. A significantly higher contralateral EMG activity and a more asymmetric EMG activity were observed in the CMD group than in the healthy subjects (Kruskal-Wallis Test).These results suggest a different behavior of bilateral sternocleidomastoid EMG activity in CMD patients than in healthy subjects depending on the positioning of the head and neck.     

Biomechanical and Bone Histomorphological Evaluation of Two Surfaces on Tapered and Cylindrical Root Form Implants: An Experimental Study in Dogs

Purpose: The aim of this study was to evaluate the early bone response of tapered and cylindrical root form implants with two different surface treatments in fresh extraction sockets after 4 and 8 weeks. Materials and Methods: Surface treatments and implant design comprised (n = 9 each): tapered with dual acid‐etched surface; tapered with dual acid‐etched and sandblasted surface (T DAE SB); cylindrical with dual acid‐etched surface (C DAE); and cylindrical with dual acid‐etched and sandblasted surface (C DAE SB). Implants were placed in the distal sockets of mandibular premolars (₂P_2,3P_3,4P₄) of six beagle dogs, remaining in vivo for 4 and 8 weeks. After sacrifice, the implants were subjected to torque to the point of interface fracture and subsequently nondecalcified for histomorphological study. Statistical analysis was performed by a General Linear Model (GLM) analysis of variance model with a significance level of 5%. Results: Torque to interface fracture was significantly greater for the C DAE SB group than for the other groups (p < .001). Histomorphological analysis showed woven bone formation around all implant surfaces at 4 weeks and its replacement by lamellar bone at 8 weeks. Study time (4 or 8 weeks) did not affect torque measures. Conclusions: The double acid‐etched and sandblasted sample surface increased early bone biomechanical fixation of both cylindrical and tapered root form implants. The cylindrical root form implants showed higher torque to interface fracture values when compared with the tapered root form implants. The C DAE SB surface group showed the highest biomechanical fixation values (p < .001).