Structure and Function of the Lateral Giant Neurone of the Primitive Crustacean Anaspides Tasmaniae

1979 ◽  
Vol 78 (1) ◽  
pp. 121-136
Author(s):  
GERALD E. SILVEY ◽  
IAN S. WILSON
Keyword(s):  
Action Potentials ◽  
Tactile Stimulation ◽  
Large Diameter ◽  
Whole Body ◽  
Giant Fibre ◽  
Single Action ◽  
Giant Neurone ◽  
And Function ◽  
Thoracic And Abdominal ◽  
Stimulation Of

The syncarid crustacean Anaspides tasmaniae rapidly flexes its free thoracic and abdominal segments in response to tactile stimulation of its body. This response decrements but recovers in slightly more than one hour. The fast flexion is evoked by single action potentials in the lateral of two large diameter fibres (40 μm) which lie on either side of the cord. The lateral giant fibre is made up of fused axons of 11 neurones, one in each of the last 5 thoracic and 6 abdominal ganglia. The soma of each neurone lies contralateral to the axon. Its neurite crosses that of its counterpart in the commissure and gives out dendrites into the neuropile of each hemiganglion. The lateral giant neurone receives input from the whole body but fires in response only to input from the fourth thoracic segment posteriorly. Both fibres respond with tactile stimulation of only one side. Since neither current nor action potentials spread from one fibre to the other, afferents must synapse with both giant neurones. The close morphological and physiological similarities of the lateral giant neurone in Anaspides to that in the crayfish (Eucarida) suggest that the lateral giant system arose in the ancestor common to syncarids and eucarids, prior to the Carboniferous.

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...

scholarly journals Scanned optogenetic control of mammalian somatosensory input to map input-specific behavioral outputs

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Ara Schorscher-Petcu ◽  
Flóra Takács ◽  
Liam E Browne
Keyword(s):  
Action Potentials ◽  
Whole Body ◽  
Head Orientation ◽  
Behavioral Measures ◽  
Single Action ◽  
Somatosensory Input ◽  
Low Threshold ◽  
Freely Behaving ◽  
Remote Touch ◽  
Slow Onset

Somatosensory stimuli guide and shape behavior, from immediate protective reflexes to longer-term learning and higher-order processes related to pain and touch. However, somatosensory inputs are challenging to control in awake mammals due to the diversity and nature of contact stimuli. Application of cutaneous stimuli is currently limited to relatively imprecise methods as well as subjective behavioral measures. The strategy we present here overcomes these difficulties, achieving 'remote touch' with spatiotemporally precise and dynamic optogenetic stimulation by projecting light to a small defined area of skin. We mapped behavioral responses in freely behaving mice with specific nociceptor and low-threshold mechanoreceptor inputs. In nociceptors, sparse recruitment of single action potentials shapes rapid protective pain-related behaviors, including coordinated head orientation and body repositioning that depend on the initial body pose. In contrast, activation of low-threshold mechanoreceptors elicited slow-onset behaviors and more subtle whole-body behaviors. The strategy can be used to define specific behavioral repertoires, examine the timing and nature of reflexes, and dissect sensory, motor, cognitive and motivational processes guiding behavior.

Escape from Recurring Tactile Stimulation in Branchiomma Vesiculosum

1965 ◽  
Vol 42 (2) ◽  
pp. 307-322 ◽  
Author(s):  
FRANKLIN B. KRASNE
Keyword(s):  
Ventral Nerve Cord ◽  
Tactile Stimulation ◽  
The Body ◽  
Direct Stimulation ◽  
Giant Fibre ◽  
Sensory Ending ◽  
Tactile Stimuli ◽  
Escape Reflex ◽  
Giant Fibres ◽  
Stimulation Of

1. Branchiomma's rapid escape from tactile stimuli is mediated by the pair of giant nerve axons which run the length of the body above the ventral nerve cord. 2. The giant neurons are connected by very stable, polarized junctions to giant motor axons. 3. The giant-fibre escape reflex fails if tactile stimuli are repeated; a non-giant system which continues to cause slower escape eventually fails also. 4. Recovery from reflex failure is slow. 5. The failure of the rapid escape reflex occurs prior to the giant fibre. It is not primarily due to sensory ending accommodation. It cannot be caused by direct stimulation of the giant fibres.

scholarly journals Potential Role of Medullary Raphe-Spinal Neurons in Cutaneous Vasoconstriction: An In Vivo Electrophysiological Study

2002 ◽  
Vol 87 (2) ◽  
pp. 901-911 ◽  
Author(s):  
Eugene Nalivaiko ◽  
William W. Blessing
Keyword(s):  
Blood Flow ◽  
Electrical Stimulation ◽  
Action Potentials ◽  
Tactile Stimulation ◽  
Central Nucleus ◽  
Nociceptive Stimulation ◽  
Spinal Neurons ◽  
Trigeminal Stimulation ◽  
Cutaneous Blood ◽  
Stimulation Of

In rabbits, raphe magnus/pallidus neurons form a link in the CNS pathway regulating changes in cutaneous blood flow elicited by nociceptive stimulation and activation of the central nucleus of the amygdala. To characterize relevant raphe-spinal neurons, we performed extracellular recordings from the rostral medullary raphe nuclei in anesthetized, paralyzed, mechanically ventilated rabbits. All studied neurons were antidromically activated from the dorsolateral funiculus of the spinal cord (C8–T2). Of 129 studied neurons, 40% were silent. The remaining neurons discharged spontaneously at 0.3–29 Hz. Nociceptive stimulation (lip squeeze with pliers) excited 63 (49%), inhibited 9 (7%), and did not affect 57 (44%) neurons. The same stimulation also elicited falls in ear pinna blood flow. In neurons activated by the stimulation, the increase in discharge preceded the fall in flow. Electrical stimulation of the spinal trigeminal tract excited 61/63 nociception-activated neurons [onset latencies range: 6–75 ms, mean: 28 ± 3 (SE) ms], inhibited 9/9 nociception-inhibited neurons (onset latencies range: 9–85 ms, mean: 32 ± 10 ms), and failed to affect 55/57 neurons insensitive to nociceptive stimulation. Neurons insensitive to nociceptive/trigeminal stimulation were also insensitive to nonnociceptive tactile stimulation and to electrical stimulation of the amygdala. They were either silent (32/45) or discharged regularly at low frequencies. They possessed long-duration action potentials (1.26 ± 0.08 ms) and slow-conducting axons (6.0 ± 0.5 m/s). These neurons may be serotonergic raphe-spinal cells. They do not appear to be involved in nociceptive-related cutaneous vascular control. Of the 63 neurons sensitive to nociceptive and trigeminal tract stimulation, 35 also responded to tactile stimulation (wide receptive field). These neurons possessed short action potentials (0.80 ± 0.03 ms) and fast-conducting axons (30.3 ± 3.1 m/s). In this subpopulation, electrical stimulation of the amygdala activated nearly all neurons tested (10/12), with a mean onset latency of 34 ± 3 ms. The remaining 28 neurons sensitive to nociceptive and trigeminal stimulation did not respond to tactile stimuli and were mainly unaffected by amygdala stimulation. It may be that fast-conducting raphe-spinal neurons, with wide multimodal receptive fields and with input from the central nucleus of the amygdala, constitute the bulbo-spinal link in the CNS pathway regulating cutaneous blood flow in response to nociceptive and alerting stimuli.

scholarly journals Structure and function of the nervous system in nectophores of the siphonophore Nanomia bijuga

2020 ◽  
Vol 223 (24) ◽  
pp. jeb233494
Author(s):  
Tigran P. Norekian ◽  
Robert W. Meech
Keyword(s):  
Action Potentials ◽  
Time Course ◽  
Lower Surface ◽  
Muscle Fibres ◽  
Muscle System ◽  
Slow Potentials ◽  
Nerve Tracts ◽  
System Part ◽  
And Function ◽  
Stimulation Of

ABSTRACTAlthough the bell-shaped nectophores of the siphonophore Nanomia bijuga are clearly specialized for locomotion, their complex neuroanatomy described here testifies to multiple subsidiary functions. These include secretion, by the extensively innervated ‘flask cells' located around the bell margin, and protection, by the numerous nematocytes that line the nectophore's exposed ridges. The main nerve complex consists of a nerve ring at the base of the bell, an adjacent column-shaped matrix plus two associated nerve projections. At the top of the nectophore the upper nerve tract appears to have a sensory role; on the lower surface a second nerve tract provides a motor input connecting the nectophore with the rest of the colony via a cluster of nerve cells at the stem. N. bijuga is capable of both forward and backward jet-propelled swimming. During backwards swimming the water jet is redirected by the contraction of the Claus' muscle system, part of the muscular velum that fringes the bell aperture. Contractions can be elicited by electrical stimulation of the nectophore surface, even when both upper and lower nerve tracts have been destroyed. Epithelial impulses elicited there, generate slow potentials and action potentials in the velum musculature. Slow potentials arise at different sites around the bell margin and give rise to action potentials in contracting Claus’ muscle fibres. A synaptic rather than an electrotonic model more readily accounts for the time course of the slow potentials. During backward swimming, isometrically contracting muscle fibres in the endoderm provide the Claus' fibres with an immobile base.

The whole-body withdrawal response of Lymnaea stagnalis. II. Activation of central motoneurones and muscles by sensory input

1991 ◽  
Vol 158 (1) ◽  
pp. 97-116 ◽  
Author(s):  
G. P. Ferguson ◽  
P. R. Benjamin
Keyword(s):  
Action Potentials ◽  
Sensory Input ◽  
Lymnaea Stagnalis ◽  
Intact Animal ◽  
The Body ◽  
Resting Potential ◽  
Whole Body ◽  
Withdrawal Response ◽  
Stimulation Of

The role of centrally located motoneurones in producing the whole-body withdrawal response of Lymnaea stagnalis (L.) was investigated. The motoneurones innervating the muscles used during whole-body withdrawal, the columellar muscle (CM) and the dorsal longitudinal muscle (DLM) were cells with a high resting potential (−60 to −70 mV) and thus a high threshold for spike initiation. In both semi-intact and isolated brain preparations these motoneurones showed very little spontaneous spike activity. When spontaneous firing was seen it could be correlated with the occurrence of two types of spontaneous excitatory postsynaptic potential (EPSP). One was a unitary EPSP that occasionally caused the initiation of single action potentials. The second was a larger-amplitude, long-duration (presumably compound) EPSP that caused the motoneurones to fire a burst of high-frequency action potentials. This second type of EPSP activity was associated with spontaneous longitudinal contractions of the body in semi-intact preparations. Tactile stimulation of the skin of Lymnaea evoked EPSPs in the CM and DLM motoneurones and in some other identified cells. These EPSPs summated and usually caused the motoneurone to fire action potentials, thus activating the withdrawal response muscles and causing longitudinal contraction of the semi-intact animal. Stimulating different areas of the body wall demonstrated that there was considerable sensory convergence on the side of the body ipsilateral to stimulation, but less on the contralateral side. Photic (light off) stimulation of the skin of Lymnaea also initiated EPSPs in CM and DLM motoneurones and in some other identified cells in the central nervous system (CNS). Cutting central nerves demonstrated that the reception of this sensory input was mediated by dermal photoreceptors distributed throughout the epidermis. The activation of the CM and DLM motoneurones by sensory input of the modalities that normally cause the whole-body withdrawal of the intact animal demonstrates that these motoneurones have the appropriate electrophysiological properties for the role of mediating whole-body withdrawal.

Inhibition of paraventricular neurons by subfornical organ and AV3V in cats

1988 ◽  
Vol 255 (6) ◽  
pp. R961-R967 ◽  
Author(s):  
T. Osaka ◽  
H. Yamashita ◽  
K. Koizumi
Keyword(s):  
Electrical Stimulation ◽  
Action Potentials ◽  
Subfornical Organ ◽  
Chemical Stimulation ◽  
Large Animal ◽  
Lamina Terminalis ◽  
Sodium Glutamate ◽  
Pentobarbital Sodium ◽  
Single Action ◽  
Stimulation Of

The study was designed to examine, by electrophysiological techniques, influences of rostral periventricular structures on neurons in the hypothalamic paraventricular nucleus (PVN) in a large animal (the cat) in which stimulating and recording sites could be precisely identified. Extracellular single action potentials were recorded from the PVN in pentobarbital sodium-anesthetized and hemispherectomized cats. Of 246 neurons tested, 24-47% were inhibited and 9-21% were excited by electrical stimulation of the subfornical organ (SFO), the nucleus preopticus medianus (POMn), and the organum vasculosum of the lamina terminalis (OVLT). The onset latencies of inhibition (19-26 ms) were shorter than those of excitation (28-80 ms). Responses of both neurosecretory and nonneurosecretory neurons were similar to the stimulation of all sites tested. Among these sites, the POMn had the strongest influence on the PVN in view of the proportion of the responsive neurons. Moreover, antidromically evoked action potentials in the PVN neurons (n = 10) were only observed after stimulation of the POMn. Chemical stimulation of POMn and SFO by microinjection of sodium glutamate (50-100 nl, 0.5 M) also inhibited 16 of 38 PVN cells; the remaining neurons were unaffected. These results suggest that activation of the POMn, OVLT, and the SFO neurons mainly inhibits the PVN neurons in the cat.

The Initiation of Action Potentials in the Somatic Musculature of Ascaris Lumbricoides

1967 ◽  
Vol 46 (2) ◽  
pp. 263-279
Author(s):  
J. DEL CASTILLO ◽  
W. C. DE MELLO ◽  
T. MORALES
Keyword(s):  
Membrane Potential ◽  
Direct Current ◽  
Action Potentials ◽  
Safety Margin ◽  
Nerve Fibres ◽  
Muscle Belly ◽  
Single Action ◽  
Somatic Musculature ◽  
Spike Firing ◽  
Stimulation Of

1. The site and mechanism of initiation of the rhythmic action potentials controlling the somatic musculature of Ascaris have been reinvestigated. 2. Polarization of the muscle syncytium by direct current injection revealed little accommodation. Action potentials are generated continuously at this region at a frequency which depends on the membrane potential. 3. Excitatory and inhibitory nerve fibres control the membrane potential of the syncytial membrane and, therefore, the frequency of spike firing. The effects of stimulation of these fibres are described. 4. The resumption of electrical activity when cooled, quiescent preparations were warmed up was studied. The first signs of activity are slow rhythmic depolarizations on which bursts of abortive spikes are superimposed. When the amplitude of the transients in each burst increases sufficiently they unite into a large, single action potential. 5. Evidence is presented suggesting that each of the abortive spikes represents the separate, subthreshold excitation of one of the terminal branches of the muscle arm, due to a low safety margin for the conduction of impulses towards the muscle belly. 6. Small (1-2 mV.) spontaneous, apparently random, depolarizations and hyperpolarizations have been recorded with microelectrodes inserted into the syncytial region. Their possible synaptic origin is discussed.

Neuronal Mechanisms Underlying the Laryngeal Adductor Reflex

2011 ◽  
Vol 120 (11) ◽  
pp. 755-760 ◽  
Author(s):  
Qi-Jian Sun ◽  
Jia Min Chum ◽  
Tara G. Bautista ◽  
Paul M. Pilowsky ◽  
Robert G. Berkowitz
Keyword(s):  
Action Potentials ◽  
Superior Laryngeal Nerve ◽  
Laryngeal Nerve ◽  
Short Latency ◽  
Occurrence Rate ◽  
Sprague Dawley ◽  
Single Action ◽  
Long Latency ◽  
Laryngeal Adductor Reflex ◽  
Stimulation Of

Objectives: Electromyographic studies of the laryngeal adductor reflex, glottal closure occurring in response to laryngeal stimulation, have demonstrated an early ipsilateral response (R1) and a late bilateral response (R2). To better define the physiologic properties of these responses, we recorded responses from expiratory laryngeal motoneurons (ELMs) in rats during stimulation of the superior laryngeal nerve (SLN). Methods: Single unit extracellular recordings were obtained from 5 ELMs, identified by their antidromic responses to recurrent laryngeal nerve stimulation and postinspiratory firing pattern, in 4 Sprague-Dawley rats. Results: Unilateral stimulation of the SLN (at 20 Hz) stopped both phrenic nerve inspiratory activity and ELM postinspiratory activity. However, the ELMs displayed robust tonic firing, consisting of non-respiratory burst activity and single action potentials. The single action potentials were identified as short-latency ones (5 to 10 ms) activated by ipsilateral SLN stimulation, with an occurrence rate of 90%, and long-latency ones (20 to 50 ms) activated by bilateral SLN stimulation, with occurrence rates of 47% on the ipsilateral side and 58% on the contralateral side. Conclusions: The R1 response appears to be the result of the short-latency action potentials, orthodromically activated by ipsilateral stimulation of the SLN. The R2 response is likely to be a result of the long-latency action potentials that can be recorded from ELMs on both sides.

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