The Input-Output Organization Of a Pair of Giant Neurones in the Mollusc, Anisodoris Nobilis (MACFARLAND)

1969 ◽  
Vol 51 (3) ◽  
pp. 615-634
Author(s):  
A. L. F. GORMAN ◽  
M. MIROLLI
Keyword(s):  
Synaptic Contact ◽  
Excitatory Input ◽  
Cell Functions ◽  
G Cells ◽  
G Cell ◽  
Intracellular Stimulation ◽  
Peripheral Cells ◽  
P Cells ◽  
Post Synaptic Potential ◽  
Stimulation Of

1. Each of the two gastro-oesophageal ganglia of the nudibranch mollusc, Anisodoris nobilis, contains one giant neurone (G cell) whose axon is directed toward the oesophagus in the gastro-oesophageal nerve. 2. In the absence of stimulation the G cells are normally silent. However, they receive inhibitory and excitatory synaptic inputs from more central ganglia and a predominantly excitatory input from the periphery. The inputs from the central ganglia are bilaterally distributed to both G cells, whereas the inputs from the periphery are limited to the ipsilateral G cell. 3. Intracellular stimulation shows that there is no interaction between the G cells, nor between the G cell and other cells in the same or contralateral gastro-oesophageal ganglia. 4. The axon of the G cell makes synaptic contact with a series of peripheral cells (P cells). In most P cells the post-synaptic potential elicited by intracellular stimulation of the G cell is constant in amplitude and latency and probably results from a unitary monosynaptic contact. Intracellular stimulation shows that the P cells are not connected to the G cell. 5. The P cells are inter-connected by low-resistance electrotonic junctions which allow slow potentials of either polarity to spread between cells. These junctions exist between distant as well as adjacent peripheral neurones. 6. Our results show that the G cell functions as a command interneurone for an aggregate of electrically interconnected peripheral neurones.

Control of feeding motor output by paracerebral neurons in brain of Pleurobranchaea californica

1982 ◽  
Vol 47 (5) ◽  
pp. 885-908 ◽  
Author(s):  
R. Gillette ◽  
M. P. Kovac ◽  
W. J. Davis
Keyword(s):  
Feeding Behavior ◽  
Action Potentials ◽  
Tactile Stimulation ◽  
Natural Food ◽  
Buccal Ganglion ◽  
Pleurobranchaea Californica ◽  
Feeding Rhythm ◽  
Intracellular Stimulation ◽  
Motor Rhythm ◽  
Stimulation Of

1. A population of interneurons that control feeding behavior in the mollusk Pleurobranchaea has been analyzed by dye injection and intracellular stimulation/recording in whole animals and reduced preparations. The population consists of 12-16 somata distributed in two bilaterally symmetrical groups on the anterior edge of the cerebropleural ganglion (brain). On the basis of their position adjacent to the cerebral lobes, these cells have been named paracerebral neurons (PCNs). This study concerns pme subset pf [MCs. the large, phasic ones, which have the strongest effect on the feeding rhythm (21). 2. Each PCN sends a descending axon via the ipsilateral cerebrobuccal connective to the buccal ganglion. Axon branches have not been detected in other brain or buccal nerves and hence the PCNs appear to be interneurons. 3. In whole-animal preparations, tonic intracellular depolarization of the PNCs causes them to discharge cyclic bursts of action potentials interrupted by a characteristic hyperpolarization. In all specimens that exhibit feeding behavior, the interburst hyperpolarization is invariably accompanied by radula closure and the beginning of proboscis retraction (the "bite"). No other behavorial effect of PCN stimulation has been observed. 4. In whole-animal preparations, the PCNs are excited by food and tactile stimulation of the oral veil, rhinophores, and tentacles. When such stimuli induce feeding the PCNs discharge in the same bursting pattern seen during tonic PCN depolarization, with the cyclic interburst hyperpolarization phase locked to the bit. When specimens egest an unpalatable object by cyclic buccal movements, however, the PCNs are silent. The PCNs therefore exhibit properties expected of behaviorally specific "command" neurons for feeding. 5. Silencing one or two PCNs by hyperpolarization may weaken but does not prevent feeding induced by natural food stimuli. Single PCNs therefore can be sufficient but are not necessary to induction of feeding behavior. Instead the PCNs presumably operate as a population to control feeding. 6. In isolated nervous system preparations tonic extracellular stimulation of the stomatogastric nerve of the buccal ganglion elicits a cyclic motor rhythm that is similar in general features to the PNC-induced motor rhythm. Bursts of PCN action potentials intercalated at the normal phase position in this cycle intensify the buccal rhythm. Bursts of PCN impulses intercalated at abnormal phase positions reset the buccal rhythm. The PCNs, therefore, also exhibit properties expected of pattern-generator elements and/or coordinating neurons for the buccal rhythm. 7. The PCNs are recruited into activity when the buccal motor rhythm is elicited by stomatogastric nerve stimulation or stimulation of the reidentifiable ventral white cell. The functional synergy between the PCNs and the buccal rhythm is therefore reciprocal. 8...

Identification of Mechanoafferent Neurons in Terrestrial Snail: Response Properties and Synaptic Connections

2002 ◽  
Vol 87 (5) ◽  
pp. 2364-2371 ◽  
Author(s):  
Aleksey Y. Malyshev ◽  
Pavel M. Balaban
Keyword(s):  
Avoidance Behavior ◽  
Receptive Fields ◽  
Dorsal Surface ◽  
Mechanical Stimulus ◽  
Terrestrial Snail ◽  
Mechanosensory Neurons ◽  
Intracellular Stimulation ◽  
Pleural Ganglion ◽  
Withdrawal Response ◽  
Stimulation Of

In this study, we describe the putative mechanosensory neurons, which are involved in the control of avoidance behavior of the terrestrial snail Helix lucorum. These neurons, which were termed pleural ventrolateral (PlVL) neurons, mediated part of the withdrawal response of the animal via activation of the withdrawal interneurons. Between 15 and 30 pleural mechanosensory neurons were located on the ventrolateral side of each pleural ganglion. Intracellular injection of neurobiotin revealed that all PlVL neurons sent their axons into the skin nerves. The PlVL neurons had no spontaneous spike activity or fast synaptic potentials. In the reduced “CNS-foot” preparations, mechanical stimulation of the skin covering the dorsal surface of the foot elicited spikes in the PlVL neurons without any noticeable prepotential activity. Mechanical stimulus-induced action potentials in these cells persisted in the presence of high-Mg2+/zero-Ca2+ saline. Each neuron had oval-shaped receptive field 5–20 mm in length located on the dorsal surface of the foot. Partial overlapping of the receptive fields of different neurons was observed. Intracellular stimulation of the PlVL neurons produced excitatory inputs to the parietal and pleural withdrawal interneurons, which are known to control avoidance behavior. The excitatory postsynaptic potentials (EPSPs) in the withdrawal interneurons were induced in 1:1 ratio to the PlVL neuron spikes, and spike-EPSP latency was short and highly stable. These EPSPs also persisted in the high-Mg2+/high-Ca2+ saline, suggesting monosynaptic connections. All these data suggest that PlVL cells were the primary mechanosensory neurons.

Role of the Subthalamic Nucleus in Cannabinoid Actions in the Substantia Nigra of the Rat

1997 ◽  
Vol 77 (3) ◽  
pp. 1635-1638 ◽  
Author(s):  
M. Clara Sañudo-Peña ◽  
J. Michael Walker
Keyword(s):  
Substantia Nigra ◽  
Subthalamic Nucleus ◽  
Cannabinoid Receptors ◽  
Excitatory Input ◽  
Physiological Regulation ◽  
Cannabinoid Antagonist ◽  
Substantia Nigra Reticulata ◽  
Cannabinoid Agonist ◽  
Stimulation Of

Sañudo-Peña, M. Clara and J. Michael Walker. Role of the subthalamic nucleus in cannabinoid actions in the substantia nigra of the rat. J. Neurophysiol. 77: 1635–1638, 1997. The effect of cannabinoids on the excitatory input to the substantia nigra reticulata (SNr) from the subthalamic nucleus was explored. For this purpose a knife cut was performed rostral to the subthalamic nucleus to isolate the subthalamic nucleus and the SNr from the striatum, a major source of cannabinoid receptors to the SNr. The data showed that the cannabinoid agonist WIN55,212-2 blocked the increase in the firing rate of SNr neurons induced by stimulation of the subthalamic nucleus with bicuculline. Furthermore, the cannabinoid antagonist SR141716A antagonized the effect of the cannabinoid agonist. This study showed that cannabinoids regulate not only the striatonigral pathway, as previously reported, but also the subthalamonigral pathway. The opposite influences of these two inputs to the SNr, inhibitory and excitatory respectively, suggest that endogenous cannabinoids play a major role in the physiological regulation of the SNr.

Organization of rat vibrissa motor cortex and adjacent areas according to cytoarchitectonics, microstimulation, and intracellular stimulation of identified cells

2004 ◽  
Vol 479 (4) ◽  
pp. 360-373 ◽  
Author(s):  
Michael Brecht ◽  
Andreas Krauss ◽  
Sajjad Muhammad ◽  
Laleh Sinai-Esfahani ◽  
Sebastiano Bellanca ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Intracellular Stimulation ◽  
Stimulation Of

Adhesion of the Boston ivy tendril

1977 ◽  
Vol 55 (8) ◽  
pp. 918-924 ◽  
Author(s):  
Anton G. Endress ◽  
William W. Thomson
Keyword(s):  
Cell Walls ◽  
Tactile Stimulation ◽  
Electron Microscopic Examination ◽  
Ruthenium Red ◽  
Contact Interface ◽  
Electron Microscopic ◽  
Colloidal Iron ◽  
Peripheral Cells ◽  
Adhesive Secretion ◽  
Stimulation Of

Tactile stimulation of Boston ivy tendrils results in the development of bilaterally symmetric discs which adhere to substrates in the vicinity of the tendrils. Our electron microscopic examination of the tendrils indicates that adhesive secretion occurs from the peripheral cells at the contact face of the discs. Cell walls in this region develop pockets which fill with adhesive and ultimately coalesce. In fully adherent discs, the adhesive occupies the region between the substrate and the cells as well as the intracellular regions between the peripheral cells. While a cuticle was present on immature discs, no cuticle-like material was observed at the contact interface of mature discs.Staining of the adhesive was enhanced by ruthenium red and potassium ferrocyanide treatments, and the adhesive bound both colloidal iron and thorium. These results indicated that the adhesive is possibly a mucopolysaccharide.

Reconfiguration of the Respiratory Network at the Onset of Locust Flight

1998 ◽  
Vol 80 (6) ◽  
pp. 3137-3147 ◽  
Author(s):  
Jan-Marino Ramirez
Keyword(s):  
Respiratory Activity ◽  
Respiratory Rhythm ◽  
Quiescent State ◽  
Suboesophageal Ganglion ◽  
Rhythm Generator ◽  
Locust Flight ◽  
Respiratory Network ◽  
Intracellular Stimulation ◽  
Tonic Stimulation ◽  
Stimulation Of

Ramirez, Jan-Marino. Reconfiguration of the respiratory network at the onset of locust flight. J. Neurophysiol. 80: 3137–3147, 1998. The respiratory interneurons 377, 378, 379 and 576 were identified within the suboesophageal ganglion (SOG) of the locust. Intracellular stimulation of these neurons excited the auxillary muscle 59 (M59), a muscle that is involved in the control of thoracic pumping in the locust. Like M59, these interneurons did not discharge during each respiratory cycle. However, the SOG interneurons were part of the respiratory rhythm generator because brief intracellular stimulation of these interneurons reset the respiratory rhythm and tonic stimulation increased the frequency of respiratory activity. At the onset of flight, the respiratory input into M59 and the SOG interneurons was suppressed, and these neurons discharged in phase with wing depression while abdominal pumping movements remained rhythmically active in phase with the slower respiratory rhythm (Fig. 9 ). The suppression of the respiratory input during flight seems to be mediated by the SOG interneuron 388. This interneuron was tonically activated during flight, and intracellular current injection suppressed the respiratory rhythmic input into M59. We conclude that the respiratory rhythm generator is reconfigured at flight onset. As part of the rhythm-generating network, the interneurons in the SOG are uncoupled from the rest of the respiratory network and discharge in phase with the flight rhythm. Because these SOG interneurons have a strong influence on thoracic pumping, we propose that this neural reconfiguration leads to a behavioral reconfiguration. In the quiescent state, thoracic pumping is coupled to the abdominal pumping movements and has auxillary functions. During flight, thoracic pumping is coupled to the flight rhythm and provides the major ventilatory movements during this energy-demanding locomotor behavior.

Activity of commissural interneurons in spinal cord of Xenopus embryos

1984 ◽  
Vol 51 (6) ◽  
pp. 1257-1267 ◽  
Author(s):  
S. R. Soffe ◽  
J. D. Clarke ◽  
A. Roberts
Keyword(s):  
Spinal Cord ◽  
Rhythmic Activity ◽  
Excitatory Input ◽  
Cycle Period ◽  
Fictive Locomotion ◽  
Anatomy And Physiology ◽  
Postsynaptic Potential ◽  
Natural Stimulation ◽  
Xenopus Laevis Embryos ◽  
Stimulation Of

Horseradish peroxidase- (HRP) filled microelectrodes have been used to examine the anatomy and physiology of "commissural interneurons," a morphologically defined class of spinal cord interneuron in Xenopus laevis embryos. Commissural interneurons have unipolar cell bodies in the dorsal half of the spinal cord. Their dendrites lie in the mid to ventral parts of the lateral tracts and their axons cross the cord ventrally, T branch, and ascend and descend on the opposite side of the cord. Recordings were made from animals immobilized in tubocurarine and responding to natural stimulation with three patterns of fictive motor activity. During episodes of fictive swimming, commissural interneurons are phasically excited to fire 1 spike/cycle in phase with motor discharge on the same side and receive a midcycle inhibitory postsynaptic potential (IPSP) in phase with motor discharge on the opposite side. Rhythmic activity is superimposed on a background depolarization. During periods of synchrony, phasic excitatory input doubles in frequency so that cells fire with half the swimming cycle period. The background depolarization is generally stronger than during swimming. During periods of fictive struggling, evoked by electrical stimulation of the skin, commissural interneurons fire a burst of spikes per cycle, cells being relatively hyperpolarized when motoneurons on the opposite side are active. In response to ipsilateral skin stimulation, some cells receive an IPSP at a latency of 12-20 ms. This precedes the onset of fictive locomotion. We discuss how anatomy and activity of commissural interneurons is suitable for a reciprocal inhibitory role.

Response properties and synaptic connections of mechanoafferent neurons in cerebral ganglion of Aplysia

1979 ◽  
Vol 42 (4) ◽  
pp. 954-974 ◽  
Author(s):  
S. C. Rosen ◽  
K. R. Weiss ◽  
I. Kupfermann
Keyword(s):  
Receptive Field ◽  
Motor Neurons ◽  
Receptive Fields ◽  
Cerebral Ganglion ◽  
The Body ◽  
Sensory Response ◽  
Tactile Stimuli ◽  
Dorsal Portion ◽  
Intracellular Stimulation ◽  
Stimulation Of

1. The cells of two clusters of small neurons on the ventrocaudal surface of each hemicerebral ganglion of Aplysia were found to exhibit action potentials following tactile stimuli applied to the skin of the head. These neurons appear to be mechanosensory afferents since they possess axons in the nerves innervating the skin and tactile stimulation evokes spikes with no prepotentials, even when the cell bodies are sufficiently hyperpolarized to block some spikes. The mechanosensory afferents may be primary afferents since the sensory response persists after chemical synaptic transmission is blocked by bathing the ganglion and peripheral structures in seawater with a high-Mg2+ and low-Ca2+ content. 2. The mechanosensory afferents are normally silent and are insensitive to photic, thermal, and chemical stimuli. A punctate tactile stimulus applied to a circumscribed region of skin can evoke a burst of spikes. If the stimulus is maintained at a constant forces, the mechanosensory response slowly adapts over a period of seconds. Repeated brief stimuli have little or no effect on spike frequency within a burst. 3. Approximately 81% of the mechanoafferent neurons have a single ipsilateral receptive field. The fields are located on the lips, the anterior tentacles, the dorsal portion of the head, the neck, or the perioral zone. Because many cells have collateral axons in the cerebral connectives, receptive fields elsewhere on the body are a possibility. The highest receptive-field density was associated with the lips. Within each area, receptive fields vary in size and shape. Adjacent fields overlap and larger fields frequently encompass several smaller ones. The features of some fields appear invariant from one animal to the next. A loose form of topographic organization of the mechanoafferent cells was observed. For example, cells located in the medial cluster have lip receptive fields, and most cells in the posterolateral portion of the lateral clusters have tentacle receptive fields. 4. Intracellular stimulation of individual mechanoafferents evokes short and constant-latency EPSPs in putative motor neurons comprising the identified B-cell clusters of the cerebral ganglion. On the basis of several criteria, these EPSPs appear to be several criteria, these EPSPs appear to be chemically mediated and are monosynaptic. 5. Repetitive intracellular stimulation of individual mechanoafferent neurons at low rates results in a gradual decrement in the amplitude of the EPSPs evoked in B cluster neurons. EPSP amplitude can be restored following brief periods of rest, but subsequent stimulation leads to further diminution of the response. 6. A decremented response cannot be restored by strong mechanical stimulation outside the receptive field of the mechanoafferent or by electrical stimulation of the cerebral nerves or connectives...

scholarly journals Dexamethasone induces sodium-dependant vitamin C transporter in a mouse osteoblastic cell line MC3T3-E1

2001 ◽  
Vol 86 (2) ◽  
pp. 145-149 ◽  
Author(s):  
I. Fujita ◽  
J. Hirano ◽  
N. Itoh ◽  
T. Nakanishi ◽  
K. Tanaka
Keyword(s):  
Vitamin C ◽  
Cell Line ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Culture Conditions ◽  
Osteoblastic Cell ◽  
Prostaglandin E ◽  
Osteoblastic Cell Line ◽  
Cell Functions ◽  
Stimulation Of

The regulation of intracellular ascorbic acid (AsA) levels may be under the control of an AsA-specific membrane transporter. The present study investigates AsA uptake and expression of Na-dependent vitamin C transporter (SVCT) mRNA in the mouse osteoblastic cell line, MC3T3-E1. Among eight compounds tested, dexamethasone (Dex) all-trans retinoic acid, transforming growth factor β, prostaglandin E2 and transferrin significantly (P<0·01, P<0·01, P<0·05 and P<0·01 respectively) stimulated the update of AsA into MC3T3-E1 cells. Among these five, Dex was the most active, inducing mSVCT2 mRNA and the uptake of AsA in a time- and concentration-dependant manner. Dex did not induce mSVCT1 mRNA. These results suggest that the Dex-induced stimulation of AsA incorporation into osteoblastic cells is mediated by the induction of mSVCT2. Since Dex reduced alkaline phosphatase activity in MC3T3-E1 cells in our culture conditions, Dex-induced stimulation of AsA incorporation might not be the result of differentiation. Hormone-regulated changes of SVCT expression may have an important role in cell functions.

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