Functions of Chordotonal Sensilla in Bushcrickets (Orthoptera, Tettigoniidae)

Acoustic and vibrational sensitivity of single identified auditory receptors in bushcrickets was studied by electrophysiological methods. In the intermediate organ, some neurons were identified whose response to acceleration did not depend on the stimulus frequency over a significant frequency range; along with them, there were cells showing increased sensitivity to frequencies of 0.4–0.8 kHz for displacement, and/or 0.1–0.3, 1–1.2, and 1.4–3 kHz for all the vibration parameters. In addition, most of the studied receptors had a zone of increased sensitivity to highfrequency vibrations at 1.5–2.5 kHz. In the sensilla of the crista acustica, increased sensitivity was recorded at frequencies of 0.1–0.3, 0.4–0.8, 1–1.2, and 1.4–2.5 kHz. The best frequencies of a single sensillum may lie in different frequency ranges for different vibration parameters. Such differences in sensitivity to vibration acceleration, vibration velocity, and displacement, and also the different best frequencies in the receptors of the intermediate organ and the crista acustica were probably determined by differences in size, position, and morphological details of the sensilla, their own resonances, and reactions to resonance vibrations of the trachea section bearing the vibroreceptors. Thus, the chordotonal sensillum is a bifunctional mechanoreceptor which, along with auditory sensitivity, can combine the functions of both a displacement receiver and an accelerometer due to the different mechanical properties of its cells and the surrounding structures.

INFLUENCE OF KINESITHERAPY ON PATIENTS WITH DIABETIC POLYNEUROPATHY

Diabetes tends to increase steadily, and is one of the most common endocrinological diseases. This disease has a high prevalence, and the incidence is increasing every year both in the world and in our country. There are several risk factors for DMD, but the main risk factor is low glycemic control (chronic hyperglycaemia). With each increase in glycated hemoglobin by 1%, the chances of developing DMD are increased. Age is also one of the major factors (the longer the DM lasts, the greater the chances of developing diabetic polyneuropathy).The causes of diabetic polyneuropathy may be known, hereditary or non-hereditary, but sometimes the causes remain unknown. The aim is to study the effectiveness of a kinesiotherapy method, based on modern principles of neurorehabilitation in improving the functional status of patients with diabetic polyneuropathy. Patients were selected according to several criteria in order to have homogeneity of the study: to be between 40 and 60 years of age; have type 2 diabetes diagnosed; have diagnosed diabetic polyneuropathy - distal symmetric sensory motor neuropathy of the lower extremities; not have severe cardiovascular and respiratory insufficiency as well as severe cognitive impairment; have stable hemodynamics, and arterial pressure is below 160/95; to move without auxiliary means. The subjects were treated with a specialized kinesiotherapy method based on the modern principles of neurorehabilitation in DPN. For the purposes of the study, a complex set of diagnostic methods is applied, and the results from which are evaluated on day 1, day 10, and month 1 of treatment are shown in a worksheet. For the purpose of the study, a complex set of diagnostic methods is applied, and the results from which are evaluated on day 1, day 10 and month 1 of treatment are shown in a worksheet.Assessed: sensory capabilities with peripheral sensitivity test (pain) and deep sensitivity (discriminatory and vibrational sensitivity) motor capabilities with manual muscle test (MMT) and centimeter and equilibrium abilities with single leg test. Results and Discussion: The presented results provide an opportunity to analyze the effect of applied kinesiotherapy. For this purpose, follow-up of various evaluated parameters was performed at baseline, on day 10 and on month 1 of treatment. This design is respected in all patients with PDD included in the study. The specialized kinesiology method stabilizes the permanently functional motor revascularization and equilibration potential of patients with PDD. Conclusion: This is a complex study of the potential of kinesiotherapy to overcome sensory, motor, and balance deficits in continued outpatient treatment of patients with PDD. It has been carried out with modern test methods, which give the opportunity to evaluate the changes in the parameters examined, in terms of sensory, motor and equilibrium possibilities after specialized kinesiotherapy. The presence of positive change in all functional parameters was observed after the administration of specialized kinesiotherapy in all subjects.

A Characterization of Saw Filters’ Vibrational Sensitivity

A novel characterization method for discrete saw filters’ vibrational sensitivity is presented. The proposed approach allows the characterization of filters under vibrations and the extraction of a behavioural model. Filters are assumed to be transducers so that external induced vibrational energy is partially transformed in an undesired simultaneous amplitude and phase modulation of the input RF signal. When the filter is mechanically excited with vibrations, it introduces spurious amplitude and phase modulation to the input signal that can potentially affect the link quality.

Saw Filters Vibrational Sensitivity Characterization

A novel characterization method for discrete saw filters vibrational sensitivity is presented. The proposed approach allows the characterization of filters under vibrations and the extraction of a behavioural model. Filters are assumed to be transducers so that external induced vibrational energy is partially transformed in a undesired simultaneous amplitude and phase modulation of the input RF signal. When the filter is mechanically excited with vibrations, it introduces spurious amplitude and phase modulation to the input signal that can potentially affect the link quality.

Earless toads sense low frequencies but miss the high notes

Sensory losses or reductions are frequently attributed to relaxed selection. However, anuran species have lost tympanic middle ears many times, despite anurans' use of acoustic communication and the benefit of middle ears for hearing airborne sound. Here we determine whether pre-existing alternative sensory pathways enable anurans lacking tympanic middle ears (termed earless anurans) to hear airborne sound as well as eared species or to better sense vibrations in the environment. We used auditory brainstem recordings to compare hearing and vibrational sensitivity among 10 species (six eared, four earless) within the Neotropical true toad family (Bufonidae). We found that species lacking middle ears are less sensitive to high-frequency sounds, however, low-frequency hearing and vibrational sensitivity are equivalent between eared and earless species. Furthermore, extratympanic hearing sensitivity varies among earless species, highlighting potential species differences in extratympanic hearing mechanisms. We argue that ancestral bufonids may have sufficient extratympanic hearing and vibrational sensitivity such that earless lineages tolerated the loss of high frequency hearing sensitivity by adopting species-specific behavioural strategies to detect conspecifics, predators and prey.

Functional Characteristics of the Parallel SI- and SII-Projecting Neurons of the Thalamic Ventral Posterior Nucleus in the Marmoset

The functional organization of the primate somatosensory system at thalamocortical levels has been a matter of controversy, in particular, over the extent to which the primary and secondary somatosensory cortical areas, SI and SII, are organized in parallel or serial neural networks for the processing of tactile information. This issue was investigated for the marmoset monkey by recording from 55 single tactile-sensitive neurons in the lateral division of the ventral posterior nucleus of the thalamus (VPL) with a projection to either SI or SII, identified with the use of the antidromic collision technique. Neurons activated from the hand and distal forearm were classified according to their peripheral source of input and characterized in terms of their functional capacities to determine whether the directthalamic input can account for tactile processing in both SI and SII. Both the SI- and SII-projecting samples contained a slowly adapting (SA) class of neurons, sensitive to static skin displacement, and purely dynamically sensitive tactile neurons that could be subdivided into two classes. One was most sensitive to high-frequency (≥100 Hz) cutaneous vibration whose input appeared to be derived from Pacinian sources, while the other was sensitive to lower frequency vibration (≤100 Hz) or trains of rectangular mechanical pulse stimuli, that appeared to receive its input from rapidly adapting (RA) afferent fibers presumed to be associated with intradermal tactile receptors. There appeared to be no systematic differences in functional capacities between SI- and SII-projecting neurons of each of these three classes, based on receptive field characteristics, on the form of stimulus-response relations, and on measures derived from these relations. These measures included threshold and responsiveness values, bandwidths of vibrational sensitivity, and the capacity for responding to cutaneous vibrotactile stimuli with phase-locked, temporally patterned impulse activity. The analysis indicates that low-threshold, high-acuity tactile information is conveyed directly to both SI and SII from overlapping regions within the thalamic VP nucleus. This direct confirmation of a parallel functional projection to both SI and SII in the marmoset is consistent with our separate studies at the cortical level that demonstrate first, that tactile responsiveness in SII largely survives the SI inactivation and second,that SI responsiveness is largely independent of SII. It therefore reinforces the evidence that SI and SII occupy a hierarchically equivalent network for tactile processing.