Interneurones Co-Ordinating the Ventilatory Movements of the Thoracic Spiracles in the Locust

1982 ◽  
Vol 97 (1) ◽  
pp. 385-400
Author(s):  
MALCOLM BURROWS
Keyword(s):  
Cell Body ◽  
Synaptic Input ◽  
Intracellular Recording ◽  
The Other ◽  
Constant Frequency ◽  
Initial Frequency ◽  
Inspiratory Phase ◽  
Metathoracic Ganglion ◽  
Motor Neurones ◽  
The Right

A pair of interneurones has been identified by intracellular recording and staining which co-ordinates the movements of the thoracic spiracles in the ventilatory rhythm. An interneurone has its cell body on the left or on the right side of the metathoracic ganglion and an axon which ascends to the other thoracic ganglia in the contralateral connective. Each interneurone produces bursts of spikes in time with the inspiratory phase of ventilation. These spikes evoke inhibitory post-synaptic potentials (IPSPs) in thoracic spiracular closer motor neurones. Both interneurones synapse upon the closer motor neurones in each thoracic segment. These connexions, which may be direct, inhibit the spiking of the closer motor neurones during inspiration. The interneurones do not appear to have an innate rhythmicity but instead receive a periodic synaptic input which inhibits their spikes during expiration. The underlying cause of the spikes is less clear. Apart from brief periods at the start and end of a burst, the spikes occur at a constant frequency that is independent of the ventilatory rate. The pattern of the spiracular motor output could be altered by manipulating the frequency and number of spikes in an interneurone. When the frequency of spikes in the interneurone was raised, the motor bursts had a higher initial frequency and were of briefer duration; when the frequency was lowered, the motor bursts were of lower initial frequency and of longer overall duration. Altering the spikes in one interneurone, however, could not affect the frequency of the ventilatory rhythm, or reset the rhythm.

The Physiology and Morphology of Median Nerve Motor Neurones in the Thoracic Ganglia of the Locust

1982 ◽  
Vol 96 (1) ◽  
pp. 325-341
Author(s):  
MALCOLM BURROWS
Keyword(s):  
Synaptic Input ◽  
Motor Neurone ◽  
Abdominal Muscles ◽  
Thoracic Ganglia ◽  
Synaptic Potentials ◽  
Metathoracic Ganglion ◽  
Inspiratory Motor ◽  
Motor Neurones ◽  
Chemical Synapses ◽  
The Right

Simultaneous intracellular recordings have been made from the two expiratory, and from the two inspiratory motor neurones which have their axons in the unpaired median nerves of the thoracic ganglia. Each motor neurone has an axon that branches to innervate muscles on the left and on the right side of one segment. The expiratory neurones studied were those in the meso- and meta-thoracic ganglia which innervate spiracular closer muscles. The depolarizing synaptic potentials underlying the spikes during expiration are common to the two closer motor neurones in a particular segment. Similarly, during inspiration when there are usually no spikes, the hyperpolarizing, inhibitory potentials are also common to both motor neurones. The synaptic input to the neurones can be derived from four interneurones; two responsible for the depolarizing potentials during expiration and two for the inhibitory potentials during inspiration. The inspiratory neurones studied were those in the abdominal ganglia fused to the metathoracic ganglion which innervate dorso-ventral abdominal muscles. During inspiration the two motor neurones of one segment spike at a similar and steady frequency. The underlying synaptic input to the two is common. During expiration, when there are usually no spikes, the hyperpolarizing synaptic potentials are also common to both neurones. In addition they match exactly the depolarizing potentials occurring at the same time in the closer motor neurones. The same set of interneurones could be responsible. No evidence has been revealed to indicate that the two closer, or the two inspiratory motor neurones of one segment are directly coupled by electrical or chemical synapses. The morphology of both types of motor neurone is distinct from that of other motor neurones in these ganglia. Both types branch extensively in both the left and in the right areas of the neuropile.

scholarly journals Innervation patterns of inhibitory motor neurones in the thorax of the locust

1985 ◽  
Vol 117 (1) ◽  
pp. 401-413 ◽  
Author(s):  
J. P. Hale ◽  
M. Burrows
Keyword(s):  
Intracellular Recording ◽  
Simultaneous Recording ◽  
Muscle Fibres ◽  
Innervation Pattern ◽  
Synaptic Coupling ◽  
Synaptic Inputs ◽  
Metathoracic Ganglion ◽  
Innervation Patterns ◽  
Motor Neurones ◽  
The Common

The innervation pattern of inhibitory motor neurones of the locust has been revealed by intracellular recording from their cell bodies in the meso- and metathoracic ganglion and simultaneous recording from muscle fibres in a middle, or in a hind leg. Three neurones in each ganglion, the common inhibitor (CI = CI1), the anterior inhibitor (AI = CI2), and the posterior inhibitor (PI = CI3) innervate several muscles in one leg and are thus common inhibitory neurones. Metathoracic CI innervates 13 muscles in one hind leg and mesothoracic CI innervates 12 muscles in one middle leg. The muscles are all in the proximal parts of the legs and move the coxa, the trochanter and the tibia. Metathoracic AI and PI innervate four muscles in the more distal parts of one hind leg that move the tibia, the tarsus and the unguis. None of these muscles is innervated by CI. Each inhibitor innervates muscles that have different and often antagonistic actions during movements of a leg. AI and PI receive many synaptic inputs in common and show similar patterns of spikes during imposed movements of a tibia. Tests fail, however, to reveal evidence for any electrical or synaptic coupling between them. A revised scheme of nomenclature for these inhibitory neurones is proposed.

scholarly journals The Identification of Motor Neurones Innervating an Abdominal Ventilatory Muscle in the Locust

1983 ◽  
Vol 107 (1) ◽  
pp. 115-127 ◽  
Author(s):  
QIN-ZHAO YANG
Keyword(s):  
Cell Body ◽  
Contralateral Side ◽  
The Body ◽  
Dorsal Muscle ◽  
The Third ◽  
Metathoracic Ganglion ◽  
Motor Neurones ◽  
Left And Right ◽  
Ventral Muscle ◽  
Ventilatory Muscles

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.

Participation of an Unpaired Motor Neurone in the Bilaterally Organized Oesophageal Rhythm in the Lobsters Jasus Lalandii and Palinurus Vulgaris

1981 ◽  
Vol 90 (1) ◽  
pp. 205-230
Author(s):  
M. MOULINS ◽  
F. NAGY
Keyword(s):  
Cell Body ◽  
Motor Neurone ◽  
The Other ◽  
Rock Lobster ◽  
Tonic Activation ◽  
Left And Right ◽  
Motor Rhythm ◽  
Pass Through ◽  
The Right

1. The main oesophageal motor neurone (OD1) of the rock lobster is an unpaired bifurcating nerve cell. The cell body is located in the oesophageal ganglion and the left and right axonal branches pass through the left and right commissural ganglia to innervate all the oesophageal dilator muscles. 2. Three types of potentials are recorded in the cell body in vitro; each type is associated with an extracellular spike recorded from the nerves connecting the ganglia. 3. Comparison between the three types of potentials (and the extracellular spikes) and collision experiments shows that all three are spikes. 4. Spontaneous collisions can sometimes occur and it is concluded that one spike is generated in the oesophageal ganglion (somatofugal a-spike) while the other two are generated in the left commissural ganglion (somatopetal c-spike) or the right commissural ganglion (somatopetal c-spike). 5. Each spike initiating zone is synaptically driven. 6. The commissural zones fire short phasic bursts; each burst is composed of only one type of spike (b- or c-). The oesophageal (a-) zone gives a tonic discharge interrupted when the other zones are firing. Finally, combined firing of the spike initiating zones can generate three different patterns of discharge. 7. OD1 participates in the oesophageal motor rhythm produced by two oscillators (one in each commissural ganglion) which fire alternated series of bursts. 8. It is concluded that the three axonal spike initiating zones enable the motor neurone (1) to follow the oesophageal motor rhythm at any time regardless of which oscillator is in operation and (2) to co-ordinate phasic and tonic activation of the oesophageal dilator muscles.

Modes of activation of motoneurons controlling ventilatory movements of the locust abdomen

1974 ◽  
Vol 269 (896) ◽  
pp. 29-48 ◽  
Keyword(s):  
Synaptic Input ◽  
Ventral Surface ◽  
Excitatory Input ◽  
The Other ◽  
Intracellular Recordings ◽  
Phase 3 ◽  
Synaptic Inputs ◽  
Frequency Code ◽  
Metathoracic Ganglion ◽  
Stimulation Of

1. Intracellular recordings have been made from tonic and phasic expiratory, inspiratory and spiracular motoneurons and presumed sensory integrating neurons of the metathoracic ganglion in a locust during rhythmic ventilatory movements of the abdomen. The neurons have somata with diameters of no more than 30 μm situated on the ventral surface of the ganglion. 2. No motoneurons showed an intrinsic rhythmicity, all being driven in the ventilatory rhythm by complex patterns of synaptic inputs in one of the following ways: ( a ) excitation alone during the phase when spikes are produced (spiracle closer and some tonic expiratory motoneurons); ( b ) excitation during one phase and inhibition during the other (some tonic expiratory motoneurons); ( c ) excitation and inhibition during both phases (most motoneurons) in which one type of input dominates a particular phase. 3. The burst of spikes by a particular motoneuron may end because of a lack of excitatory input (spiracle closer motoneurons) or be terminated rapidly by inhibition (inspiratory motoneurons). Inhibition may also precede the main burst of spikes (inspiratory motoneurons) so that any spikes during the opposite phase are abolished. The pattern of synaptic input determines the frequency code of spikes within a burst. 4. Phasic expiratory motoneurons receive an underlying pattern of synaptic inputs in phase with ventilation even when they do not spike. Non-specific excitation (for example, a d.c. depolarization of the soma) is able to produce bursts of spikes in the correct phase of ventilation. 5. No direct pathway between any groups of motoneurons was found. Driving by common antecedent interneurons is inferred for those motoneurons which show similar patterns of spikes (inspiratory and spiracle closer motoneurons). 6. Stimulation of descending fibres in the pro-mesothoracic connectives evokes e.p.s.ps in some motoneurons, perhaps monosynaptically. In inspiratory motoneurons these fibres cause e.p.s.ps but will abolish the inspiratory burst of spikes and reset the ventilatory rhythm. All observations imply that the mechanism of the ventilatory rhythm lies among interneurons.

Binocular convergence of excitatory and inhibitory synaptic pathways onto neurons of cat visual cortex

1990 ◽  
Vol 4 (6) ◽  
pp. 625-629 ◽  
Author(s):  
David Ferster
Keyword(s):  
Electrical Stimulation ◽  
Visual Cortex ◽  
Receptive Field ◽  
Synaptic Input ◽  
Intracellular Recording ◽  
Cortical Neurons ◽  
Field Studies ◽  
The Other ◽  
Synaptic Potential ◽  
Stimulation Of

AbstractWhen a cortical neuron receives synaptic input from both eyes, do the synaptic pathways that mediate the input from each eye match? In this study, inputs from the two eyes were compared by measuring the latencies of EPSPs and IPSPs evoked by electrical stimulation of the two optic nerves. For binocular neurons, these latencies invariably matched closely, indicating that the pathways from the two eyes contain the same number of synapses; monosynaptic input from lamina A of the lateral geniculate nucleus (LGN) is always matched by monosynaptic input from lamina A1. Conversely, polysynaptic input from one eye, either excitatory or inhibitory, is invariably accompanied by similar input from the other eye. In addition, the match between the two eyes in latency indicates that for each eye a synaptic potential is mediated by the same type of afferent, either X or Y.Judging from intracellular recording, 75% of the neurons studied were binocular, that is, EPSPs could be evoked from either eye. In the remaining 25%, EPSPs could be evoked from only one eye, in agreement with extracellular receptive field studies in which 30% of cortical neurons are monocular.

Changes in Electrical Connection During Cell Fusion in the Heliozoan, Echinosphaerium Akamae

1988 ◽  
Vol 135 (1) ◽  
pp. 183-191
Author(s):  
TAKAKO NISHI ◽  
TSUKASA GOTOW ◽  
MAKOTO KOBAYASHI
Keyword(s):  
Membrane Fusion ◽  
Cell Fusion ◽  
Cell Body ◽  
Intracellular Recording ◽  
Early Stage ◽  
The Other ◽  
Electrical Connection ◽  
Advanced Stages ◽  
Unicellular Organisms ◽  
Paired Cell

The electrophysiology of cell fusion in the heliozoan, Echinosphaetium akamae, was studied by intracellular recording from two unicellular organisms undergoing fusion. Fusion was preceded by the electrical connection of axopodia of each cell to the cell body of the other. In the early stages of the fusion process, spikes evoked in one cell body failed to invade the other, but electrotonic potentials (subthreshold depolarizations) did pass to the other cell. When background depolarizing currents were injected into the organism into which the potentials had invaded, these potentials developed into spikes. In advanced stages of fusion, spikes were transmitted in both directions from one organism to the other, in the absence of polarizing current. At this time, application of appropriate hyperpolarizing currents to either of the two organisms prevented spikes produced in one from invading the other. These results suggest that in the early stage of fusion, relatively few axopodia were bridged by membrane fusion between paired cell bodies, and that the number of such bridged axopodia increased as fusion proceeded, allowing spikes to be transmitted between the two organisms.

Assessment of knowledge of oral health hygiene among coastal guards in the port trust of south Tamil Nadu - A public health awareness survey

2020 ◽  
Vol 11 (SPL3) ◽  
pp. 1861-1868
Author(s):  
Bianca Princeton ◽  
Abilasha R ◽  
Preetha S
Keyword(s):  
Lung Cancer ◽  
Oral Health ◽  
Oral Hygiene ◽  
Tamil Nadu ◽  
Asbestos Exposure ◽  
The Other ◽  
Oral Manifestations ◽  
Illegal Activities ◽  
The Right ◽  
Oral Hygiene Habits

Oral hygiene is defined as the practice of keeping the mouth clean and healthy, by brushing and flossing to prevent the occurrence of any gum diseases like periodontitis or gingivitis. The main aim of oral health hygiene is to prevent the buildup of plaque, which is defined as a sticky film of bacteria and food formed on the teeth. The coastal guard is an official who is employed to watch the sea near a coast for ships that are in danger or involved with illegal activities. Coastal guards have high possibilities of being affected by mesothelioma or lung cancer due to asbestos exposure. So, a questionnaire consisting of 20 questions was created and circulated among a hundred participants who were coastal guards, through Google forms. The responses were recorded and tabulated in the form of bar graphs. Out of a hundred participants, 52.4% were not aware of the fact that coastal guards have high chances of developing lung cancer and Mesothelioma. 53.7% were aware of the other oral manifestations of lung cancer other than bleeding gums. Majority of the coastal guards feel that they are given enough information about dental hygiene protocols. Hence, to conclude, oral hygiene habits have to be elaborated using various tools in the right manner to ensure better health of teeth and gums.

JUAL BELI TANAH YANG DILAKUKAN TANPA AKTA PPAT

2018 ◽  
Vol 4 (1) ◽  
pp. 89-107
Author(s):  
Cheri Bayuni Budjang
Keyword(s):  
Everyday Life ◽  
Government Regulation ◽  
Land Rights ◽  
The Other ◽  
Legal Certainty ◽  
Land Registration ◽  
The Future ◽  
The Right ◽  
Laws And Regulations

Buying and selling is a way to transfer land rights according to the provisions in Article 37 paragraph (1) of Government Regulation Number 24 of 1997 concerning Land Registration which must include the deed of the Land Deed Making Official to register the right of land rights (behind the name) to the Land Office to create legal certainty and minimize the risks that occur in the future. However, in everyday life there is still a lot of buying and selling land that is not based on the laws and regulations that apply, namely only by using receipts and trust in each other. This is certainly very detrimental to both parties in the transfer of rights (behind the name), especially if the other party is not known to exist like the Case in Decision Number 42 / Pdt.G / 2010 / PN.Mtp

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