Use Of Simultaneous Recording Research Articles

Visual coding along multiple brain areas

This study focuses on understanding visual coding in multiple brain areas and its implications for neural processing in the visual system. It highlights the use of simultaneous recordings of large neuronal populations to investigate how visual information is encoded and processed in the brain. By studying the activity of multiple brain areas, the paper aims to uncover the mechanisms underlying brain-wide visual perception and provide insights into the neural basis of visual processing. The findings of this research contribute to the broader field of neuroscience and have implications for understanding visual disorders and developing therapeutic interventions

Relationship of Cerebral Hemodynamics and Cerebral Bioelectrical Activity in Patients with Cervical Osteochondrosis

Introduction . Osteochondrosis of the cervical spine is a very common disease that causes a significant decrease in the quality of life of patients. In the case of pronounced changes in the cervical spine with osteochondrosis, there is a violation of blood circulation in the cerebral cortex, which leads to pronounced clinical symptoms. The aim of this study was to identify a correlation between bioelectrical activity and cerebral hemodynamics in patients with osteochondrosis of the cervical spine. Materials and methods . The examination involved 25 patients of the neurosurgical department who received conservative treatment for exacerbation of osteochondrosis of the cervical spine, and 25 volunteers without a history of diseases of the spine and joints. The cerebral bioelectrical activity and blood flow indicators were recorded in the pool of the common carotid and vertebral arteries. Results . In the main group and the clinical comparison group, the rheographic index and the peripheral vascular resistance index were studied, which characterize both the volume pulse blood filling of the vascular bed and the tone of small and medium caliber arteries. At the same time, the EEG rhythm indices were analyzed: а -, в -, S-, and в -waves. An analysis of the intersystem interaction of bloodflow indices and the biopotentials of the cortical rhythm of the brain in the main group showed a mismatch in the intra-system connections, which corresponds to the period of the general stress of the body. An analysis of the correlation between the indicators of electroencephalography and rheoencepha-lography in the control group revealed a stable system of correlation between the indicators, showing intersystem and intrasystem consistency and reflecting a high level of reserve capacity of the body and the state of steady adaptation to adverse factors. Conclusion . The use of simultaneous recording of cerebral hemodynamics and brain biopotentials in patients with osteochondrosis of the cervical spine will allow clinicians to correctly assess the functional state of the central nervous system and to prescribe adequate treatment in a timely manner.

A Novel Stimulation Paradigm for Obtaining Interfrequency Amplitude Ratio of Ocular Vestibular Evoked Myogenic Potentials.

Purpose Interfrequency amplitude ratio (IFAR), the ratio of amplitude between ocular vestibular evoked myogenic potentials (oVEMPs) for tone bursts of 500 and 1000 Hz, aids in identification of Ménière's disease with high sensitivity and specificity. However, it requires recording of oVEMP for 2 frequencies, which doubles the time of recording. Use of simultaneous recording of responses for both frequencies could potentially bring down testing time. Simultaneous recording might be possible by modifying the oddball paradigm and using a ratio of 1:1 for the 2 frequencies. This might also reduce variation in oVEMP amplitude between frequencies due to changes in gaze angle between the recordings. However, it remains to be explored whether or not the use of modified oddball paradigm to record oVEMP (MoVEMP) will produce comparable responses to conventional sequential recording of oVEMP (CoVEMP) for obtaining IFAR. Hence, the study aimed to compare MoVEMP and CoVEMP on various measures of oVEMP. Method The study included 29 healthy adults in the age range of 18-30 years, 23 of which were used for validation and 6 for finding test-retest reliability. All participants underwent contralateral oVEMP recording using 500- and 1000-Hz tone bursts presented using MoVEMP and CoVEMP paradigms. Results Comparable outcomes on latencies, amplitude, and IFAR were obtained between CoVEMP and MoVEMP. Furthermore, MoVEMP took significantly lesser time per ear and also produced better test-retest reliability than CoVEMP. Conclusion MoVEMP is a quicker and more reliable clinical stimulation paradigm for obtaining IFAR than CoVEMP.

Dissimilar Effects of Tolterodine on Detrusor Overactivity in Awake Rats with Chemical Cystitis and Partial Bladder Outlet Obstruction

PurposeWe investigated bladder function, with a special focus on nonvoiding contractions (NVCs), in awake rats with chronic chemical cystitis and bladder outlet obstruction (BOO) by use of simultaneous registrations of intravesical and intraabdominal pressures. In addition, we tested the effects of tolterodine on the NVCs in these models.MethodsA total of 20 female Sprague-Dawley rats were used in this study. In eight rats, chemical cystitis was induced by intravesical instillation of HCl. Twelve rats were subjected to sham instillations or partial BOO. Four weeks after intravesical instillation or 2 weeks after partial BOO, cystometrograms were obtained by use of simultaneous recording of intravesical and intraabdominal pressure in all unanesthetized, unrestrained rats in metabolic cages.ResultsA total of 17 rats survived. In the rats with acute injury by HCl, 50% showed detrusor overactivity (DO), which was not seen in the sham group. The cystitis group had lower DO pressure without a difference in DO frequency compared with the BOO group. After the administration of tolterodine, the cystitis group showed no difference in DO frequency or pressure, whereas the BOO group showed decreased values for both parameters.ConclusionsOur study showed that toleterodine produced no effect on DO during the filling phase in rats with chronic chemical cystitisbut decreased the frequency and pressure of DO in rats with BOO. Clinically, studies are needed to improve the treatment effect of anticholinergic drugs ininterstitial cystitis patients with overactive bladder.

Polysynaptic potentiation at different levels of rat olfactory pathways following learning.

This study was aimed at investigating the consequences of learning on late polysynaptic components of evoked field potential signals recorded in parallel at different levels of the olfactory pathways. For this, evoked field potentials induced by electrical stimulation of the olfactory bulb were recorded simultaneously in the anterior piriform cortex, the posterior piriform cortex, the lateral entorhinal cortex, and the dentate gyrus. The different parameters of late components were measured in each site before and after completion of associative learning in anesthetized rats. In the learning task, rats were trained to associate electrical stimulation of one olfactory bulb electrode with the delivery of sucrose (positive reward) and stimulation of a second olfactory bulb electrode with the delivery of quinine (negative reward). In this way, stimulation of the same olfactory bulb electrodes used for inducing field potentials served as a discriminative cue in the learning paradigm. The data confirmed previous observation that learning was associated with a lowering in late-component-1 intensity of induction in the posterior piriform cortex. The use of simultaneous recording allowed us to further specify the consequences of learning on late-component distribution in the studied network. Indeed the data showed that whereas before learning, late component 1 was rather uniformly distributed among the recorded sites; following learning, its expression was facilitated preferentially in the posterior piriform cortex and lateral entorhinal cortex. Furthermore, learning was accompanied by the emergence of a new late component (late component 2), which occurred simultaneously in the four recording sites. The possible involvement of potentiation of polysynaptic components in recognition and/or consolidation processes will be discussed.

Widespread synchronous [Ca2+]i oscillations due to bursting electrical activity in single pancreatic islets

Pancreatic beta cells, tightly organized in the islet of Langerhans, secrete insulin in response to glucose in a calcium-dependent manner. The calcium input required for this secretory activity is thought to be provided by an oscillatory electrical activity occurring in the form of "bursts" of calcium action potentials. The previous observation that islet intracellular free Ca2+ levels undergo spontaneous oscillations in the presence of glucose, together with the fact that islet cells are coupled through gap junctions, hinted at a highly effective co-ordination between individual islet cells. Through the use of simultaneous recordings of intracellular calcium and membrane potential it is now reported that the islet calcium waves are synchronized with the beta cell bursting electrical activity. This observation suggests that each calcium wave is due to Ca2+ entering the cells during a depolarized phase of electrical activity. Moreover, fura-2 fluorescence image analysis indicates that calcium oscillations occur synchronously across the whole islet tissue. The maximal phase shift between oscillations occurring in different islet cells is estimated as 2 s. This highly co-ordinated oscillatory calcium signalling system may underlie pulsatile insulin secretion and the islet behaviour as a secretory "syncytium". Since increasing glucose concentration lengthens calcium wave and burst duration without significantly affecting wave amplitude, we further propose that it is the fractional time at an enhanced Ca2+ level, rather than its amplitude, that encodes for the primary response of insulin-secreting cells to fuel secretagogues.

ONSET TIME AND DURATION OF ACTION FOR ATRACURIUM, ORG NC45 AND PANCURONIUM

Speed of onset, maximum block, duration of action and 10-25% recovery time for atracurium, Org NC 45 and pancuronium were determined using equipotent doses: 330 micrograms kg-1, 66 micrograms kg-1 and 75 micrograms kg-1 respectively. Vein-to-muscle and artery-to-muscle onset times were measured by use of simultaneous recordings. Mean speeds of onset to 95% twitch depression were: atracurium 2.7 min, Org NC 45 2.8 min and pancuronium 3.6 min. The median value of maximum neuromuscular block exceeded 98.5% for all drugs and the mean durations of action to 25% recovery of control twitch height were: atracurium 27.6 min, Org NC 45 21.9 min and pancuronium 45.1 min. The differences were statistically significant. The recovery period from 10% to 25% twitch response was considerably longer for pancuronium than for the other drugs, which did not differ significantly from each other. We were unable to validate the artery-to-muscle technique in the determination of onset time.

Use of simultaneous recording of auditory cortical-evoked potentials and cochlear microphone potentials to stydy the mechanism of auditory adaptation

Use of simultaneous recording of auditory cortical-evoked potentials and cochlear microphone potentials to stydy the mechanism of auditory adaptation

Simultaneous Recording of Ecoch G and ABR

Wave I is not always recorded clearly in ABR, and it is effective to record AP simultaneously to identify wave I. If the results of AP are taken into account, no misinter-pretation can be cccured. The simultaneous recordings of AP and ABR are averaged with same stimuli, and it is easy to place the electrodes for recording of AP and ABR Testing time can be shortened by the use of simultaneous recording, and the simultaneous AP and ABR recordings are useful for the detecion of cochlear nerve and the brain stem disorders.

The interrelationship of the electrocardiographic complexes studied by simultaneous multiple recording

1. 1. The use of simultaneous recordings of six electrocardiographic leads in twenty-three normal subjects and in thirty-three patients with a variety of cardiac lesions has afforded the opportunity of studying the genesis of the different waves through comparison of simultaneous peaks. 2. 2. Study of the precordial leads (V 1 through V 6) revealed the following: 2.1. A. There is a considerable variation in duration of the QRS complexes in the various precordial leads. 2.2. B. Peaks of the P and T waves occurred consistently earlier in V 1 than in V 6 unless the waves were inverted, in which case the peaks tended to be simultaneous. 2.3. C. Among the normal subjects, as contrasted to the patients with left ventricular hypertrophy and bundle branch block, the R wave in V 5 and V 6 did not represent the last portion of the left ventricle to be depolarized. 2.4. D. QS complexes in right ventricular leads were essentially similar in time to S rather than Q waves. 2.5. E. The peak of the R′ in bundle branch block represents the onset of the intrinsic deflection. 3. 3. Study of the unipolar extremity leads and the standard leads revealed the following: 4. A. There is a phase difference between the peaks of the P, Q, R, S, and T waves in the various standard leads. 5. B. The peak of the R wave in the unipolar extremity leads was usually not simultaneous, particularly among normal subjects. 6. C. The QS complex in V R was similar in time to an S rather than a Q wave. 7. D. With a vertical heart, the nadir of the S wave in V L followed the peak of the R wave in V F; the nadir of the S wave in V 1 followed the peak of the R wave in V 6. 8. E. A phase difference in the peaks of the P and T waves existed in the different unipolar extremity leads. 9. F. Formulas for deriving the standard leads from the unipolar extremity leads are only approximations unless the leads are taken simultaneously.