Temporal and spatial characteristics of tonically active neurons of the primate's striatum

1995 ◽  
Vol 73 (3) ◽  
pp. 1234-1252 ◽  
Author(s):  
T. Aosaki ◽  
M. Kimura ◽  
A. M. Graybiel

1. Tonically active neurons (TANs) in the primate striatum develop transient responses to sensory conditioning stimuli during behavioral training in classical conditioning tasks. In this study we examined the temporal characteristics of such TAN responses and mapped the sites of TANs responding to auditory and visual conditioned stimuli in the striatum in macaque monkeys. We further mapped the locations of TANs recorded acutely in the squirrel monkey striatum in relation to the neurochemically distinguished striosome and matrix compartments of the striatum, and made quantitative comparisons between the densities and compartmental distributions of TANs and those of four major types of striatal interneuron identified by histochemical and immunohistochemical staining. 2. We made recordings from 858 TANs at different sites in the striatum in two behaving macaque monkeys at different times during training with auditory (click) and visual (light-emitting diode flash) conditioning stimuli. TANs distributed across large parts of the striatum developed responses to the conditioning stimuli. The responses comprised a decrement of tonic firing (pause) followed by a rebound excitation. Measurements were made of the onsets, offsets, and durations of the pauses of individual TANs and of the interspike intervals (ISIs) of the same cells. 3. The mean duration of the pause responses (268.3 ms) was greater than the mean ISI of the same neurons (181 ms), suggesting that the pause represents an active suppression of TAN firing. The coefficient of variation (CV) for the pause responses was 0.28, compared with a CV of 0.63 for the same cells' ISIs. The population CV for the pauses was 0.16, compared with a population CV of 0.20 for the ISIs. These data, together with temporal analysis of the responses and population histograms, suggest that the pauses became temporally aligned across large parts of the striatum after learning. Analyses of variance (ANOVAs) were carried out to determine whether there were differences in the onset and offset latencies of the pause response or in the durations of the pause responses for TANs at different sites. These analyses suggested that, with rare exceptions, there was no difference in the timing of the TAN responses across large (> 10 mm3) parts of the striatum. 4. Comparisons of TAN responses in different regions of the striatum showed that, for responses to a given modality of conditioned stimulus, there were no significant differences in pause offset times for TANs recorded in the caudate nucleus or putamen, or for TANs recorded in more anterior or more posterior parts of these nuclei.(ABSTRACT TRUNCATED AT 400 WORDS)

2017 ◽  
Vol 4 (2) ◽  
pp. 341 ◽  
Author(s):  
Maharoof M.K. ◽  
Shamshad Ahmed Khan ◽  
Prakash Robert Saldanha ◽  
Reshad Mohamed

Background: High levels of total serum bilirubin can cause life threatening complications in neonates requiring management either with phototherapy or exchange blood transfusion. Most commonly used modality of phototherapy is with blue light. There are many bulbs like fluorescent tubes, halogen spotlights etc. Due to disadvantages of the available bulbs, newer method like light-emitting diodes (LEDs) has been investigated as possible alternatives as they produce low heat, has a longer life span with lower energy consumption and rapid reduction of serum bilirubin level. The aim was to compare the efficacy between phototherapy equipped with light emitting diode (LED) to compact fluorescent lamp (CFL) in the treatment of neonatal hyperbilirubinemia among neonates.Methods: A hospital-based intervention study was conducted among 50 neonates born in the hospital during the study period, with gestational age more than equal to 35 weeks, being breastfed and healthy in a private medical college teaching hospital in Dakshina Kannada district from August to September 2016.  Following ethical committee clearance the neonates looking icteric by clinical examination were randomly allocated to receive CFL or LED phototherapy. Baseline, 24 hour total serum bilirubin and rectal temperature was measured.  Results: A total of 50 neonates were randomly allocated into two groups with almost similar characteristics between the two groups with respect to gender, type of delivery and gestational age. The mean bilirubin values (in mg/dl) among neonates in the CFL group and LED group were 14.8 and 15.6 respectively and post 24 hour values were 11.54 and 10.68 respectively. The mean difference in the reduction in the bilirubin values before and after receiving phototherapy between the two groups were significant (p <0.001). The increase in temperature was lesser among LED treatment group.Conclusions: LED therapy is better than the CFL therapy in terms of mean reduction in the total serum bilirubin after a fixed duration of time and lesser raise in temperature among the neonates.  


2017 ◽  
Vol 1 (1) ◽  
pp. 10
Author(s):  
Anak Agung Aris Diartama ◽  
Susy Suswaty ◽  
Win Priantoro ◽  
Sugiyanto Sugiyanto ◽  
Sudiyono Sudiyono ◽  
...  

Background: In the process of work to gain the maximum results, a radiologist needs a viewing box tool to read radiographs. Therefore, the authors want to develop a viewing box tool, which in general the work if this tool resembles the factory manufactured tool. The viewing tool box made can adjust the intensity of the light produced.Objective: to create a viewing box tool by using a potentiometer system.Methods: This study used applied research method by creating and using the design of viewing box tool by using a potentiometer system and testing the viewing box tool created by using a Lux meter and 15 respondents consisting of five radiologists and 10 radiographers who should fulfill the questionnaire form.Results: The mean of viewing box illumination reached 220 lux. The results of the questionnaire showed that 100% radiologist gave an A (excellent) and expressed that the viewing box tool created could be used properly and 90% radiographers provided an A (excellent) and expressed that the viewing box tool created could be used properly, while 10% radiographer gave a value of B (moderate).Conclusion: viewing box tool created could be used properly and obtained optimal results as a tool in reading radiographs. Potentiometer system contained in the viewing box was very helpful in reading radiographs because it allowed to adjust the light intensity according to user needs.Keywords       :  Viewing box, Potentiometer Bibliography   : 1980-2011


Designs ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 49 ◽  
Author(s):  
Massimo Ruo Roch ◽  
Maurizio Martina

Solid state lighting is nowadays widely diffused both in residential and office or industrial environment. Ambient light sensing to modulate lamp power is typical too, but sensors inside a lamp are a challenge, due to the high flux of these sources, which easily saturates nearby light detectors. Usually, separate sensing devices must be introduced in the system, thus increasing complexity and cost. In this work, a methodology will be presented, to allow integration of a light sensing device inside a lamp, using low cost circuitry to mitigate interactions between high power light-emitting diode (LED) sources and sensing photodiodes. Moreover, the same circuit allows visual light communication among sources.


2011 ◽  
Vol 68 (suppl_1) ◽  
pp. ons1-ons6 ◽  
Author(s):  
Jair Leopoldo Raso ◽  
Segastião Nataniel Silva Gusmão

Abstract BACKGROUND: The suboccipital craniotomy is one of the most commonly performed neurosurgical approaches. OBJECTIVE: To define a new cranial landmark, the digastric point, located at the top of the mastoid notch in the mastoid portion of the temporal bone that may assist surgeons performing this craniotomy and to study the relationships between this point and other surface landmarks. METHODS: Craniometric measures were taken from 127 dry human adult skulls (90 male and 37 female). The measures were taken in millimeters by a digital caliper. Transillumination of the skull with laser or light-emitting diode was used to assess the correspondence of the digastric point in the inner surface of the skull. RESULTS: The mean distance between the digastric point and the sigmoid sulcus in 254 measures was 3.10 mm (SD, 3.11 mm). The digastric point was over the sulcus of the sigmoid sinus in 49.6% of the cases on the right side and in 29.9% of the cases on the left side. The distance between the jugular point and the stylomastoid foramen was smaller on the right side (mean, 8.89 mm; SD, 2.61 mm; P = .041). Comparing genders regardless of side, the distances between the digastric and jugular points and from the jugular point to the stylomastoid foramen were smaller in female skulls (P = .000 and .006, respectively). CONCLUSION: The digastric point may be a useful landmark to expose the sigmoid sinus during suboccipital approaches.


2020 ◽  
Vol 63 (10) ◽  
pp. 1463-1478
Author(s):  
Jianhui Zhang ◽  
Tianhao Zhang ◽  
Feilong Jiang ◽  
Bei Zhao

Abstract Neighbor discovery is a fundamental task to support many other services in wireless multihop networks (WMN). Most existing related methods in WMN rely heavily on the information of radio waves. To extend the way to the neighbor discovery, this paper introduces another interesting way, visual light communication, to explore its property of linear transmission. We apply light emitting diode (LED) array and camera and present a novel communication system, named LED array to camera system (LC). This paper also designs a novel protocol, named LED to camera protocol (LCP), for it. Equipped with an LC, each node in a WMN can determine the precise direction and distance of its neighbors and recognize their identities. Furthermore, this paper also develops a method to infer the topology of the whole network. We design the hardware for LC and conduct extensive experiments to implement the protocol LCP. The average latency of the neighbor discovery is measured and can be as small as 1.087 seconds. LCP can achieve centimeter-level accuracy in distance and direction to averages of 0.37 cm and 1.67 degrees in these real experiments. The relative accuracies in distance and direction measurement are 99.11% and 88.92% on average, respectively. The simulation of the topology inference is also performed to show the feasibility and accuracy with the local distance and direction information.


2017 ◽  
Vol 42 (1) ◽  
pp. 82-89 ◽  
Author(s):  
P Yu ◽  
AUJ Yap ◽  
XY Wang

SUMMARY This study evaluated the degree of conversion (DC) and polymerization shrinkage (PS) of contemporary bulk-fill resin-based composites (RBCs) including giomer materials. Two giomer bulk-fill (Beautifil Bulk Restorative [BBR], Beautifil Bulk Flowable [BBF]), two nongiomer bulk-fill (Tetric N-Ceram Bulk-fill [TNB], Smart Dentin Replacement [SDR]), and three conventional non–bulk-fill (Beautifil II [BT], Beautifil Flow Plus [BF], Tetric N-Ceram [TN]) RBCs were selected for the study. To evaluate the DC, disc-shaped specimens of 5-mm diameter and 2-mm, 4-mm, and 6-mm thickness were fabricated using customized Teflon molds. The molds were bulk filled with the various RBCs and cured for 20 seconds using a light-emitting diode curing light with an irradiance of 950 mW/cm2. The DC (n=3) was determined by attenuated total reflectance Fourier transform infrared spectroscopy by computing the spectra of cured and uncured specimens. PS (n=3) was measured with the Acuvol volumetric shrinkage analyzer by calculating specimen volumes before and after light curing. The mean DC for the various materials ranged from 46.03% to 69.86%, 45.94% to 69.38%, and 30.65% to 67.85% for 2 mm, 4 mm, and 6 mm, respectively. For all depths, SDR had the highest DC. While no significant difference in DC was observed between depths of 2 mm and 4 mm for the bulk-fill RBCs, DC at 2 mm was significantly greater than 6 mm. For the conventional RBCs, DC at 2 mm was significantly higher than at 4 mm and 6 mm. Mean PS ranged from 1.48% to 4.26% for BBR and BF, respectively. The DC at 2 mm and PS of bulk-fill RBCs were lower than their conventional counterparts. At 4 mm, the DC of giomer bulk-fill RBCs was lower than that of nongiomer bulk-fill materials.


2020 ◽  
pp. 144-148

Chaos synchronization of delayed quantum dot light emitting diode has been studied theortetically which are coupled via the unidirectional and bidirectional. at synchronization of chaotic, The dynamics is identical with delayed optical feedback for those coupling methods. Depending on the coupling parameters and delay time the system exhibits complete synchronization, . Under proper conditions, the receiver quantum dot light emitting diode can be satisfactorily synchronized with the transmitter quantum dot light emitting diode due to the optical feedback effect.


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