An atlas of the thoracic ganglia in the stick insect, Carausius morosus

1991 ◽  
Vol 331 (1260) ◽  
pp. 101-121 ◽  

The present report describes the neuroanatomy of the three thoracic ganglia in the stick insect, Carausius morosus , the subject of numerous behavioural and neurobiological studies. The structure of the ganglia is summarized in an atlas of the major features. The results are compared with published descriptions of other insects and arthropods. Numerous similarities with locusts encourage the use of a common nomenclature even where minor differences make homology uncertain pending detailed investigation. Five out of the nine longitudinal tracts described in locusts can be readily identified in the stick insect. Three major tracts (LDT, DIT, VIT) and two smaller tracts (MDT, DMT) are compact and well defined. The VMT and MVT are also prominent but these two tracts are not clearly separated except near the rostral margin of the neuropile. An eighth tract, the VLT, is much less distinct: it is represented by scattered fibres in neuropile lateral to the DIT. The iLVT apd oLVT, the two parts of the ninth tract, are quite inconspicuous: in some, but not all, preparations they can be identified as two thin bands running along the ventral and ventrolateral margins of the ganglion. As in locusts, six dorsal commissures (DCI-DCVI) and five ventral commissures (VCI, vVCII, dVCII, SMC, PVC) connecting the left and right hemiganglia have been named although the two most dorsal commissures, DCII and DCIV, are often subdivided. The VCII is retained as a single unit with dorsal and ventral parts. Of the dorsal-ventral tracts only the transverse tract (TT) and the circle tract (CT) are well-defined. Roots of lateral nerves are left unnamed pending more detailed study but several conspicuous branches are included in the drawings as guides to orientation in the lateral neuropile. The ventral association centre (VAC) and several other neuropile divisions are described. Pro- and mesothoracic ganglia derive from single neuromeres. The metathoracic ganglion results from the fusion of the third thoracic and the first abdominal neuromeres: each part contains its own set of commissures and dorsoventral tracts. The results underline the qualitative similarities of the thoracic ganglia in insects; they provide a basis for more precise descriptions of identified neurons and functional specialization within the ganglia of the stick insect.

1983 ◽  
Vol 107 (1) ◽  
pp. 115-127 ◽  
Author(s):  
QIN-ZHAO YANG

Motor neurones to abdominal ventilatory muscles, with their axons innerve 6 of the metathoracic ganglion of the locust, have been identified by intracellular recording and staining. Three muscles are innervated by the larger branches of this nerve: nerve 6a contains six motor neurones innervating the ventral diaphragm; nerve 6b contains four motor neurones innervating the median internal ventral muscle, and nerve 6d contains five motorneurones innervating the longitudinal dorsal muscle. All motor neuronesinnervate muscles on one side of the body only. Both the median internalventral and the longitudinal dorsal muscles contract during the expiratoryphase of ventilation. Three excitatory motor neurones to the median internalventral muscles spike during expiration whilst the fourth, an inhibitorymotor neurone, is active during both expiration and inspiration. Two of theexcitatory motor neurones have cell bodies in the half of the ganglion ipsilateralto the muscle they innervate. Their neuropilar branches, however, are in both left and right halves of the ganglion. The third excitatory motorneurone has its cell body close to the midline and has most of its neuropilarbranches in the half of the ganglion ipsilateral to its axon. The inhibitorymotor neurone has its cell body just to the contralateral side of the midline, and three distinct areas of neuropilar branches, two contralateral and oneipsilateral to its axon.


1975 ◽  
Vol 63 (3) ◽  
pp. 713-733
Author(s):  
M. Burrows

1. Some flight motoneurones receive two superimposed rhythms of depolarizing synaptic potentials when the locust is not flying; a slow rhythm which is invariably linked to the expiratory phase of ventilation, and a fast rhythm with a period of about 50 ms which is similar to the wingbeat period in flight. 2. By recording simultaneously from groups of motoneurones, the synaptic potentials which underly these rhythms have been revealed in 30 flight motoneurones in the three thoracic ganglia. The inputs occur in elevator motoneurones and some depressors but are of lower amplitude in the latter. The inputs have not been found in leg motoneurones. 3. The rhythmic depolarizations are usually subthreshold but sum with sensory inputs to evoke spikes in flight motoneurones at intervals equal to or multiples of the wingbeat period in flight. 4. Both rhythms originate in the metathoracic ganglion and are mediated by the same interneurones. They can be adequately explained by supposing that there are two symmetrical interneurones which each make widespread connexions with left and right flight motoneurones in the three ganglia. 5. The slow rhythm is coded in the overall burst of interneurone spikes during expiration and the fast rhythm in the interval between the spikes of a burst.


2015 ◽  
Vol 8 (2) ◽  
pp. 93
Author(s):  
Juniar Siregar

This study presents a research report on improving students’ Learning results on IPA through Video. The objective was to find out whether students’ learning result improved when they are taught by using Video. It was conducted using classroom action research method. The subject of the study was the Grade IV students of SDN 187/IV Kota Jambi which is located on Jln. Adi Sucipto RT 05 Kecamatan Jambi Selatan, and the number of the students were 21 persons. The instruments used were test. In analyzing the data, the mean of the students’ score for the on fisrt sycle was 65,4 (42,85%) and the mean on cycle two was 68,5 (37,15%) and the mean of the third cycle was 81,4 (100%). Then it can be concluded that the use of video on learning IPA can improve the students’ learning result. It is suggested that teachers should use video as one of the media to improve students’ learning result on IPA.Keywords : IPA, students’ learning result, video


Author(s):  
Nurmi Nurmi ◽  
Hadi Putra ◽  
Penti Nursida ◽  
Khoiro Mahbubah ◽  
Neni Hermita

This study aims to improve 3rd grade students’ science learning outcomes bylearning to use visual multimedia. This research method uses classroom actionresearch. The subject of this research was the third grade students of secondsemester of elementary school which conducted 30 students. Based on theresults of research by using visual media, it have been found that theimprovement learning outcome, seen from the initial average score before theaction of 3rd grade class students from 65.5 to 83.83. The results of this studyindicate that with the use of visual media can improve student learningoutcomes.


2016 ◽  
Vol 11 (1) ◽  
pp. 10-35
Author(s):  
Joseph Azize

The various published biographies and biographical notices of G.I. Gurdjieff (c.1865-1949) are of diverse style, quantity and content. While some have made considerable contributions to the subject, most attempts have reacted for or against Gurdjieff’s status as what might call an ‘Enlightened Master’. Little biographical writing on Gurdjieff has questioned the scope, reliability and prejudices of the sources. Further, possible resources have been neglected. The development in Gurdjieff’s ideas is often overlooked, his life is not sufficiently related to that development, and the lack of comparative research has failed to highlight Gurdjieff’s unique contributions. This article is structured in four parts. The first is an introduction, followed by an overview of existing biographical studies of Gurdjieff. The third part addresses bias in these studies, and this is followed by suggestions for future studies. It is concluded that fieldwork regarding the biography of Gurdjieff has been hampered by imperfect methodology. However, with better use of the source material, some of which has only recently been discovered, and a rigorous use of sources, a more balanced and nuanced picture of Gurdjieff’s life, and the development of his ideas and methods, should emerge.


Author(s):  
Hotria Manik ◽  
Elia Masa Ginting

This study attempts to improve students’ writing achievement in recount text through Think-Pair-Share Strategy. This study was conducted by using classroom action research. The subject of the research was class VIII-1 SMPN 1 Pematangsiantar. The number of the students was 32 students, consisted of 5 males and twenty seven females. The research was conducted in two cycles and consisted of six meetings. The instruments for collecting data were writing tests as the quantitative data and diary notes, observation sheet, interview sheet and questionnaire sheet as qualitative data. Based on the writing score, students’ scores kept improving in every test. In analyzing the data, the mean of the students’ score for the first test as a pre-test was 57.84, for the second test as a post test I was 73.56, for the third test as a post test II was 77.56. Based on diary notes, observation sheet and questionnaire sheet, it was found that students were actively involved in writing process. The result of the research showed that Think-Pair-Share Strategy can improve students’ achievement in writing recount text.   Keywords: Think Pair Share, Writing, Recount text, Action research


Author(s):  
Meryanti Napitupulu And Anni Holila Pulungan

This study was conducted as an attempt to discover the effect of applying Demonstration Method on students’ achievement in speaking skill. It was an experimental research. The subject was students of Grade XII, Vocational High School (Sekolah Menengah Kejuruan: SMK), which consisted of 79 students. The research was divided into two groups: experimental and control groups. The instrument used to collect the data was speaking test. To obtain the reliability of the test, the writer applied Kuder Richardson 21 formula. The result of the reliability was 0.7, and it was found that the test was reliable. The data were analyzed by using t-test formula. The analysis showed that the scores of the students in the experimental group were significantly higher than the scores of the students in the control group at the level of significant m = 0.05 with the degree of freedom (df) 77, t-observed value 8.9 > t-table value 1.99. The findings indicate that using Demonstration Method significantly affected the students’ achievement in speaking skill. So, English teachers are suggested to use Demonstration Method in order to improve students’ achievement in speaking skill.


Author(s):  
Esra N.F. Hutahaean And Tjut Ernidawati

This research concerns on improving students’ writing achievement in the report text through film.  The objective was to find out the improvement of students’ writing achievement in writing the report text through film. This research was conducted by using action research method. The subject of the research was XI IPA grade students of SMA SWASWTA JOSUA Medan. The numbers of students were thirty one students. They were taught writing the report text through film. The instruments used were writing report text test, diary notes, interview sheets, questionnaire sheets and observation sheets. In analyzing data, the mean of students’ score for the first competency test was 43.1, for the second competency test was 64.8 and for the third competency test was 76.3 and the total percentage of improvement from the first competency test to the third competency test was 84.1%. The conclusion is that through watching film can improve the students’ writing achievement in the report text. It is suggested that teachers should apply watching film as one of media to improve students’ writing achievement in the report text.


Author(s):  
Rini Susanti And Zainuddin

This study deals with improving the students’ vocabulary achievement byapplying Tic-tac-toe Game. The subject of this study was grade VIII1 2012/2013students of SMP Negeri 1 Payung, desa Batukarang. The total number of the classis 36 students. This study applied classroom action research which consisted oftwo cycles. Three meetings were for first cycle and two meeting for second cycle.The data were collected qualitatively and quantitatively. The data werequalitatively collected from questionnaires sheet and observation sheet, whilequantitatively from the scores of vocabulary tests; orientation test, test I, and testII. After analyzing the data, it was found that there was an improvement ofstudents’ vocabulary achievement. It was proven by the increasing of the meanscore of the students’ vocabulary scores in each test where mean score of the firsttest was 56.94, the second test (test I) was 69.30 and the third test (test II) was80.14.


2011 ◽  
Vol 42 (2) ◽  
pp. 56-64 ◽  
Author(s):  
Remigiusz Szczepanowski

Conscious access to fear-relevant information is mediated by thresholdThe present report proposed a model of access consciousness to fear-relevant information according to which there is a threshold for emotional perception beyond that the subject makes hits with no false alarm. The model was examined by having the participants performed a confidence-ratings masking task with fearful faces. Measures of the thresholds for conscious access were taken by looking at the receiver operating characteristics (ROC) curves generated from a three-state low- and high-threshold (3-LHT) model by Krantz. Indeed, the analysis of the masking data revealed that the ROCs had threshold-like-nature (a two-limb shape) rather continuous (a curvilinear shape) challenging in this fashion the classical signal-detection view on perceptual processing. Moreover, the threshold ROC curve exhibited the specific y-intercepts relevant to conscious access performance. The study suggests that the threshold can be an intrinsic property of conscious access, mediating emotional contents between perceptual states and consciousness.


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