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Richard A Satterlie - One of the best experts on this subject based on the ideXlab platform.
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Cyclic Guanosine Monophosphate Modulates Locomotor Acceleration Induced by Nitric Oxide but not Serotonin in Clione limacina Central Pattern Generator Swim Interneurons
Integrative organismal biology (Oxford England), 2021Co-Authors: Thomas J. Pirtle, Richard A SatterlieAbstract:Both nitric oxide (NO) and serotonin (5HT) mediate swim acceleration in the marine mollusk, Clione limacina. In this study, we examine the role that the second messenger, cyclic guanosine monophosphate (cGMP), plays in mediating NO and 5HT-induced swim acceleration. We observed that the application of an analog of cGMP or an activator of soluble guanylyl cyclase (sGC) increased fictive locomotor speed recorded from Pd-7 interneurons of the animal's locomotor central pattern generator. Moreover, inhibition of sGC decreased fictive locomotor speed. These results suggest that basal levels of cGMP are important for slow swimming and that increased production of cGMP mediates swim acceleration in Clione. Because NO has its effect through cGMP signaling and because we show herein that cGMP produces cellular changes in Clione swim interneurons that are consistent with cellular changes produced by 5HT application, we hypothesize that both NO and 5HT function via a common signal transduction pathway that involves cGMP. Our results show that cGMP mediates NO-induced but not 5HT-induced swim acceleration in Clione.
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changes in wingstroke kinematics associated with a change in swimming speed in a pteropod mollusk Clione limacina
The Journal of Experimental Biology, 2011Co-Authors: Brett G Szymik, Richard A SatterlieAbstract:SUMMARY In pteropod mollusks, the gastropod foot has evolved into two broad, wing-like structures that are rhythmically waved through the water for propulsion. The flexibility of the wings lends a tremendous range of motion, an advantage that could be exploited when changing locomotory speed. Here, we investigated the kinematic changes that take place during an increase in swimming speed in the pteropod mollusk Clione limacina. Clione demonstrates two distinct swim speeds: a nearly constant slow swimming behavior and a fast swimming behavior used for escape and hunting. The neural control of Clione 9s swimming is well documented, as are the neuromuscular changes that bring about Clione 9s fast swimming. This study examined the kinematics of this swimming behavior at the two speeds. High speed filming was used to obtain 3D data from individuals during both slow and fast swimming. Clione 9s swimming operates at a low Reynolds number, typically under 200. Within a given swimming speed, we found that wing kinematics are highly consistent from wingbeat to wingbeat, but differ between speeds. The transition to fast swimming sees a significant increase in wing velocity and angle of attack, and range of motion increases as the wings bend more during fast swimming. Clione likely uses a combination of drag-based and unsteady mechanisms for force production at both speeds. The neuromuscular control of Clione 9s speed change points to a two-gaited swimming behavior, and we consider the kinematic evidence for Clione 9s swim speeds being discrete gaits.
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Modulation of swimming speed in the pteropod mollusc,Clione limacina: Role of a compartmental serotonergic system
Invertebrate Neuroscience, 1996Co-Authors: Richard A Satterlie, Tigran P. NorekianAbstract:In locomotory systems, the central pattern generator and motoneuron output must be modulated in order to achieve variability in locomotory speed, particularly when speed changes are important components of different behavior acts. The swimming system of the pteropod mollusc Clione limacina is an excellent model system for investigating such modulation. In particular, a system of central serotonergic neurons has been shown to be intimately involved in regulating output of the locomotory pattern generator and motor system of Clione . There are approximately 27 pairs of serotonin-immunoreactive neurons in the central nervous system of Clione , with about 75% of these identified. The majority of these identified immunoreactive neurons are involved in various aspects of locomotory speed modulation. A symmetrical cluster of pedal serotonergic neurons serves to increase wing contractility without affecting wing-beat frequency or motoneuron activity. Two clusters of cerebral cells produce widespread responses that lead to an increase in pattern generator cycle frequency, recruitment of swim motoneurons, activation of the pedal serotonergic neurons and excitation of the heart excitor neuron. A pair of ventral cerebral neurons provides weak excitatory inputs to the swimming system, and strongly inhibits neurons of the competing whole-body withdrawal network. Overall, the serotonergic system in Clione is compartmentalized so that each subsystem (usually neuron cluster) can act independently or in concert to produce variability in locomotory speed.
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Whole body withdrawal circuit and its involvement in the behavioral hierarchy of the mollusk Clione limacina
Journal of neurophysiology, 1996Co-Authors: Tigran P. Norekian, Richard A SatterlieAbstract:1. The behavioral repertoire of the holoplanktonic pteropod mollusk Clione limacina includes a few well-defined behaviors organized in a priority sequence. Whole body withdrawal takes precedence over slow swimming behavior, whereas feeding behavior is dominant over withdrawal. In this study a group of neurons is described in the pleural ganglia, which controls whole body withdrawal behavior in Clione. Each pleural withdrawal (Pl-W) neuron has a high threshold for spike generation and is capable of inducing whole body withdrawal in a semi-intact preparation: retraction of the body-tail, wings, and head. Each Pl-W neuron projects axons into the main central nerves and innervates all major regions of the body. 2. Stimulation of Pl-W neurons produces inhibitory inputs to swim motor neurons that terminate swimming activity in the preparation. In turn, Pl-W neurons receive inhibitory inputs from the cerebral neurons involved in the control of feeding behavior in Clione, neurons underlying extrusion of specialized prey capture appendages. Thus it appears that specific inhibitory connections between motor centers can explain the dominance of withdrawal behavior over slow swimming and feeding over withdrawal in Clione.
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Cerebral serotonergic neurons reciprocally modulate swim and withdrawal neural networks in the mollusk Clione limacina
Journal of neurophysiology, 1996Co-Authors: Tigran P. Norekian, Richard A SatterlieAbstract:1. A pair of serotonin-immunoreactive neurons has been identified in the cerebral ganglia of the pteropod mollusk Clione limacina, which produce coordinated, excitatory/inhibitory effects on neuron...
Tigran P. Norekian - One of the best experts on this subject based on the ideXlab platform.
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Modulation of swimming speed in the pteropod mollusc,Clione limacina: Role of a compartmental serotonergic system
Invertebrate Neuroscience, 1996Co-Authors: Richard A Satterlie, Tigran P. NorekianAbstract:In locomotory systems, the central pattern generator and motoneuron output must be modulated in order to achieve variability in locomotory speed, particularly when speed changes are important components of different behavior acts. The swimming system of the pteropod mollusc Clione limacina is an excellent model system for investigating such modulation. In particular, a system of central serotonergic neurons has been shown to be intimately involved in regulating output of the locomotory pattern generator and motor system of Clione . There are approximately 27 pairs of serotonin-immunoreactive neurons in the central nervous system of Clione , with about 75% of these identified. The majority of these identified immunoreactive neurons are involved in various aspects of locomotory speed modulation. A symmetrical cluster of pedal serotonergic neurons serves to increase wing contractility without affecting wing-beat frequency or motoneuron activity. Two clusters of cerebral cells produce widespread responses that lead to an increase in pattern generator cycle frequency, recruitment of swim motoneurons, activation of the pedal serotonergic neurons and excitation of the heart excitor neuron. A pair of ventral cerebral neurons provides weak excitatory inputs to the swimming system, and strongly inhibits neurons of the competing whole-body withdrawal network. Overall, the serotonergic system in Clione is compartmentalized so that each subsystem (usually neuron cluster) can act independently or in concert to produce variability in locomotory speed.
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Whole body withdrawal circuit and its involvement in the behavioral hierarchy of the mollusk Clione limacina
Journal of neurophysiology, 1996Co-Authors: Tigran P. Norekian, Richard A SatterlieAbstract:1. The behavioral repertoire of the holoplanktonic pteropod mollusk Clione limacina includes a few well-defined behaviors organized in a priority sequence. Whole body withdrawal takes precedence over slow swimming behavior, whereas feeding behavior is dominant over withdrawal. In this study a group of neurons is described in the pleural ganglia, which controls whole body withdrawal behavior in Clione. Each pleural withdrawal (Pl-W) neuron has a high threshold for spike generation and is capable of inducing whole body withdrawal in a semi-intact preparation: retraction of the body-tail, wings, and head. Each Pl-W neuron projects axons into the main central nerves and innervates all major regions of the body. 2. Stimulation of Pl-W neurons produces inhibitory inputs to swim motor neurons that terminate swimming activity in the preparation. In turn, Pl-W neurons receive inhibitory inputs from the cerebral neurons involved in the control of feeding behavior in Clione, neurons underlying extrusion of specialized prey capture appendages. Thus it appears that specific inhibitory connections between motor centers can explain the dominance of withdrawal behavior over slow swimming and feeding over withdrawal in Clione.
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Cerebral serotonergic neurons reciprocally modulate swim and withdrawal neural networks in the mollusk Clione limacina
Journal of neurophysiology, 1996Co-Authors: Tigran P. Norekian, Richard A SatterlieAbstract:1. A pair of serotonin-immunoreactive neurons has been identified in the cerebral ganglia of the pteropod mollusk Clione limacina, which produce coordinated, excitatory/inhibitory effects on neuron...
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An identified cerebral interneuron initiates different elements of prey capture behavior in the pteropod mollusc,Clione limacina
Invertebrate Neuroscience, 1995Co-Authors: Tigran P. Norekian, Richard A SatterlieAbstract:The prey capture phase of feeding behavior in the pteropod mollusc Clione limacina consists of an explosive extrusion of buccal cones, specialized oral appendages which are used to catch the prey, and significant acceleration of swimming. Several groups of neurons which control different components of prey capture behavior in Clione have been previously identified in the CNS. However, the question of their coordination in order to develop a normal behavioral reaction still remains open. We describe here a cerebral interneuron which has wide-spread excitatory and inhibitory effects on a number of neurons in the cerebral and pedal ganglia, directed toward the initiation of prey capture behavior in Clione . This bilaterally symmetrical neuron, designated Cr-PC (Cerebral interneuron initiating Prey Capture), produced monosynaptic activation of Cr-A motoneurons, which control buccal cone extrusion, and inhibition of Cr-B and Cr-L motoneurons, whose spike activities maintain buccal cones in a withdrawn position inside the head in non-feeding animals. In addition, Cr-PC produced monosynaptic activation of a number of swim motoneurons and interneurons of the swim central pattern generator (CPG) in the pedal ganglia, pedal serotonergic Pd-SW neurons involved in a peripheral modulation of swimming and the serotonergic Heart Excitor neuron.
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Cerebral neurons underlying prey capture movements in the pteropod mollusc, Clione limacina. II. Afterdischarges.
Journal of comparative physiology. A Sensory neural and behavioral physiology, 1993Co-Authors: Tigran P. NorekianAbstract:The pteropod mollusc Clione limacina is a highly specialized carnivore which feeds on shelled pteropods and uses, for their capture, three pairs of oral appendages, called buccal cones. Contact with the prey induces rapid eversion of buccal cones, which then become tentacle-like and grasp the shell of the prey. In the previous paper, a large group of electrically coupled, normally silent cells (A motoneurons) has been described in the cerebral ganglia of Clione. Activation of A neurons induces opening of oral skin folds and extrusion of the buccal cones. The present study continues the analysis of the electrical properties of A motoneurons.
Yuri I. Arshavsky - One of the best experts on this subject based on the ideXlab platform.
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The Swimming Circuit in the Pteropod Mollusk Clione limacina
Handbook of Brain Microcircuits, 2017Co-Authors: Yuri I. Arshavsky, Tatiana G. Deliagina, Grigory N. OrlovskyAbstract:The pelagic marine mollusk Clione limacina (class Gastropoda, subclass Opisthobranchaea, order Pteropoda), 3–5 cm in length, swims by rhythmically moving (1–2-Hz) two winglike appendages. Each swim cycle consists of two phases—the dorsal (D) and ventral (V) wing flexions. The nervous system of Clione consists of five pairs of ganglia. The wing movements are controlled by the pedal ganglia giving rise to the wing nerves. The neuronal circuit of the swim central pattern generator (CPG) is located in the pedal ganglia, which is able to generate the basic pattern of rhythmic activity after isolation from the organism (fictive swimming). Approximately 120 pedal neurons exhibit rhythmic activity during fictive swimming. According to their morphology, rhythmic neurons are divided into motoneurons (MNs), with axons exiting via the wing nerves to wing muscles, and interneurons (INs), with axons projecting to the contralateral ganglion.
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Asymmetrical effect of GABA on the postural orientation in Clione.
Journal of neurophysiology, 2000Co-Authors: Tatiana G. Deliagina, Grigori N. Orlovsky, Allen I. Selverston, Yuri I. ArshavskyAbstract:The marine mollusk Clione limacina, when swimming, normally stabilizes the vertical body orientation by means of the gravitational tail reflexes. Horizontal swimming or swimming along inclined ascending trajectories is observed rarely. Here we report that GABA injection into intact Clione resulted in a change of the stabilized orientation and swimming with a tilt of approximately 45 degrees to the left. The analysis of modifications in the postural network underlying this effect was done with in vitro experiments. The CNS was isolated together with the statocysts. Spike discharges in the axons of two groups of motoneurons responsible for the left and right tail flexion, as well as in the axons of CPB3 interneurons mediating signals from the statocyst receptors to the motoneurons, were recorded extracellularly when the preparation was rotated in space. Normally the tail motoneurons of the left and right groups were activated with the contralateral tilt of the preparation. Under the effect of GABA, the gravitational responses in the right group of motoneurons and in the corresponding interneurons were dramatically reduced while the responses in the left group remained unchanged. The most likely site of the inhibitory GABA action is the interneurons mediating signals from the statocysts to the right group of tail motoneurons. The GABA-induced asymmetry of the left and right gravitational tail reflexes, observed in the in vitro experiments, is consistent with a change of the stabilized orientation caused by GABA in the intact Clione.
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Statomotor system in the marine mollusk Clione limacina
Journal of neurophysiology, 1995Co-Authors: Yu. V. Panchin, R. I. Sadreev, Yuri I. ArshavskyAbstract:1. In the marine mollusk Clione limacina the "statomotor system" (named by analogy with the oculomotor system) has been found. This system includes a muscle that is directly attached to the statocysts connecting them with each other and with the inner surface of the body. 2. The statocyst muscle consists of four electrically coupled, mononuclear cells. Statocyst muscle cells do not generate spike-like potentials but only excitatory junctional potentials. 3. The motor input to the statocyst muscle correlates with the activity of the locomotor generator. This suggests that in the soft-bodied Clione contraction of the statocyst muscle stabilizes the statocysts into a standard "working" position in relation to coordinates of the body. This statocyst stabilization is important for Clione's spatial orientation during swimming.
Shigefumi Kuwahara - One of the best experts on this subject based on the ideXlab platform.
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first synthesis of pteroenone a defensive metabolite of the abducted antarctic pteropod Clione antarctica
Synlett, 2005Co-Authors: Yoko Nakamura, Hiromasa Kiyota, Bill J. Baker, Shigefumi KuwaharaAbstract:(+)-Pteroenone, a defensive metabolite of the abducted antarctic pteropod Clione antarctica, was firstly and efficiently synthesized by employing anti-selective aldol reaction as the key step.
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First synthesis of (+)-pteroenone : a defensive metabolite of the abducted antarctic pteropod Clione antarctica
Synlett, 2005Co-Authors: Yoko Nakamura, Hiromasa Kiyota, Bill J. Baker, Shigefumi KuwaharaAbstract:(+)-Pteroenone, a defensive metabolite of the abducted antarctic pteropod Clione antarctica, was firstly and efficiently synthesized by employing anti-selective aldol reaction as the key step.
Yoko Nakamura - One of the best experts on this subject based on the ideXlab platform.
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first synthesis of pteroenone a defensive metabolite of the abducted antarctic pteropod Clione antarctica
Synlett, 2005Co-Authors: Yoko Nakamura, Hiromasa Kiyota, Bill J. Baker, Shigefumi KuwaharaAbstract:(+)-Pteroenone, a defensive metabolite of the abducted antarctic pteropod Clione antarctica, was firstly and efficiently synthesized by employing anti-selective aldol reaction as the key step.
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First synthesis of (+)-pteroenone : a defensive metabolite of the abducted antarctic pteropod Clione antarctica
Synlett, 2005Co-Authors: Yoko Nakamura, Hiromasa Kiyota, Bill J. Baker, Shigefumi KuwaharaAbstract:(+)-Pteroenone, a defensive metabolite of the abducted antarctic pteropod Clione antarctica, was firstly and efficiently synthesized by employing anti-selective aldol reaction as the key step.