The cardioregulatory system of crayfish: neuroanatomy and physiology

1975 ◽  
Vol 62 (3) ◽  
pp. 519-530
Author(s):  
L. H. Field ◽  
J. L. Larimer
Keyword(s):  
Procambarus Clarkii ◽  
Physiological Activity ◽  
Temporal Correlation ◽  
Reciprocal Relationship ◽  
Gill Chamber ◽  
Sensory Modalities ◽  
Hair Sensilla ◽  
Anatomical Arrangement ◽  
Dorsal Nerve ◽  
Stimulation Of

1. The anatomical arrangement of the cardioregulatory nerves and their physiological activity during cardiac modulation were analysed in Procambarus clarkii. 2. The bilaterally arranged pairs of cardioinhibitors and cardioaccelerator axons, in nerves SN II and SN III respectively, were physiologically identified by correlating spikes in SN II and SN III with the same spikes in the dorsal nerve, which innervates the heart. 3. The cardioinhibitor neurone fired tonically in varied sporadic bursts. During periods of cardiac inhibition, however, this neurone discharged in a long chain of spikes at a characteristic frequency of 40–50Hz. 4. The cardioaccelerator neurone fired tonically at 2–3 Hz but on occasion its activity reached 12 Hz. 5. Three inhibitory cardiac reflexes were analysed. The sensory modalities for the reflexes included (a) stretch of the dorsal pericardial wall, (b) chemical stimulation of coxal hair sensilla with glucose and (c) tactile stimulation of hair sensilla in and below the gill chamber, on the antennae, the antennules and on the anterior cephalothorax. 6. The discharge of both cardioinhibitor neurones showed a weak temporal correlation suggesting a common presynaptic drive, while the pair of cardioaccelerators appeared to have a reciprocal relationship with the cardioinhibitors.

Thoracic Leg Control of Abdominal Extension in the Crayfish, Procambarus Clarkii

1981 ◽  
Vol 90 (1) ◽  
pp. 85-100
Author(s):  
CHARLES H. PAGE
Keyword(s):  
Procambarus Clarkii ◽  
Mean Values ◽  
Extensor Muscles ◽  
Carpal Joint ◽  
The Mean ◽  
Leg Movement ◽  
Abdominal Appendages ◽  
Thoracic And Abdominal ◽  
Abdominal Movement ◽  
Stimulation Of

Postural extensions of the abdomen of the crayfish, Procambarus clarkii, could be evoked by mechanical stimulation of a single thoracic leg. Movement of a single leg joint was sufficient to initiate an extension response. Vigorous abdominal extensions were initiated either by depression of the whole leg (WLD) or by flexion of the mero-carpal joint (MCF). Weaker extension responses were obtained by depression of the thoracic-coxal and coxo-basal joints. Similar stimulation of the chelipeds did not elicit an abdominal extension response. Single-frame analysis of motion pictures of crayfish responding to WLD or MCF stimulation of a 2nd thoracic leg showed that the responses evoked by the two different stimulus situations were nearly identical. They differed principally in the responses of the leg located contralateral to the stimulated leg. Movements of most of the cephalic, thoracic and abdominal appendages accompanied the abdominal extension response. Only the eyes remained stationary throughout the response. The mean values of the latencies for the initiation of appendage movement ranged from 125 to 204 ma; abdominal movement had a mean latency of about 220 ms. The abdominal extension reflex resulted from the activity of the tonic superficial extensor muscles. The deep phasic extensor muscles were silent during the response. The mean latencies for the initiation of superficial extensor muscle activity by WLD and MCF stimulation were 53·7 and 50·0 ms respectively.

scholarly journals Synaesthesia in Autism

2016 ◽  
Vol 14 (3) ◽  
pp. 21-31 ◽  
Author(s):  
O.B. Bogdashina
Keyword(s):  
Autism Spectrum Disorders ◽  
Sensory Modality ◽  
Children With Autism ◽  
Autism Spectrum ◽  
Sensory Modalities ◽  
Spectrum Disorders ◽  
Stimulation Of

Synaesthesia — a phenomenon of perception, when stimulation of one sensory modality triggers a perception in one or more other sensory modalities. Synaesthesia is not uniform and can manifest itself in different ways. As the sensations and their interpretation vary in different periods of time, it makes it hard to study this phenom¬enon. The article presents the classification of different forms of synaesthesia, including sensory and cognitive; and bimodal and multimodal synaesthesia. Some synaesthetes have several forms and variants of synaesthesia, while others – just one form of it. Although synaesthesia is not specific to autism spectrum disorders, it is quite common among autistic individuals. The article deals with the most common forms of synaesthesia in autism, advantages and problems of synesthetic perception in children with autism spectrum disorders, and provides some advice to parents how to recognise synaesthesia in children with autism.

The Activity of Single Motor Fibres in Arthropods I. The Dragonfly Nymph

1965 ◽  
Vol 42 (3) ◽  
pp. 447-461
Author(s):  
ANN KNIGHTS
Keyword(s):  
Electrical Stimulation ◽  
Temporal Summation ◽  
Reciprocal Relationship ◽  
Response Patterns ◽  
Insect Muscle ◽  
Frequency Sensitivity ◽  
Single Motor ◽  
Dragonfly Nymph ◽  
Central Inhibition ◽  
Stimulation Of

1. Responses to mechanical and electrical stimulation have been investigated in single motor fibres dissected in the segmental nerves of the dragonfly nymph. 2. A large proportion of fibres possessed a background discharge which was often accelerated of inhibited on stimulation. Examples of central inhibition were common. 3. Efferent responses varied in type, delay and regularity, both with the input under stimulation and with the frequency and intensity of the volley. The majority of fibres responded to stimulation of more than one nerve root. 4. In many motor fibres changes in the parameters of stimulation demonstrated a reciprocal relationship between and frequency. An enhanced responsiveness occurred with frequency increases in the range of 10-100/sec. indicatind a considerable importance of temporal summation/facilitation. 5. The characteristic frequency-sensitivity of motor fibres and the variability of their response patterns are discussed in relation to the control of insect muscle.

A method for selective stimulation of leg chemoreceptors in whole crustaceans

2021 ◽  
Author(s):  
Paolo Solari ◽  
Giorgia Sollai ◽  
Francesco Palmas ◽  
Andrea Sabatini ◽  
Roberto Crnjar
Keyword(s):  
Procambarus Clarkii ◽  
Sensory Information ◽  
Natural Conditions ◽  
Search Behaviour ◽  
Non Invasive ◽  
Animal Survival ◽  
Sensory Motor ◽  
Reflex Activation ◽  
Motor Outputs ◽  
Stimulation Of

The integration of sensory information with adequate motor outputs is critical for animal survival. Here, we present an innovative technique based on a non-invasive closed-circuit device consisting of a perfusion/stimulation chamber chronically applied on a single leg of the crayfish Procambarus clarkii. Using this technique, we focally stimulated the leg inside the chamber and studied the leg-dependent sensory-motor integration involving other sensory appendages, such as antennules and maxillipeds, which remain unstimulated outside the chamber. Results show that the stimulation of a single leg with chemicals, such as disaccharides, is sufficient to trigger a complex search behaviour involving locomotion coupled with the reflex activation of antennules and maxillipeds. This technique can be easily adapted to other decapods and/or other sensory appendages. Thus, it has opened possibilities for studying sensory-motor integration evoked by leg stimulation in whole aquatic animals under natural conditions to supplement, with a direct approach, current ablation/silencing techniques.

Modulatory effects of nitric oxide on synaptic depression in the crayfish neuromuscular system

2000 ◽  
Vol 203 (23) ◽  
pp. 3595-3602 ◽  
Author(s):  
H. Aonuma ◽  
T. Nagayama ◽  
M. Takahata
Keyword(s):  
Nitric Oxide ◽  
Neuromuscular Transmission ◽  
Procambarus Clarkii ◽  
Synaptic Depression ◽  
Physiological Property ◽  
Muscle Fibres ◽  
Flexor Muscle ◽  
Bath Application ◽  
Flexor Muscles ◽  
Stimulation Of

A characteristic physiological property of the neuromuscular junction between giant motor neurones (MoGs) and fast flexor muscles in crayfish is synaptic depression, in which repetitive electrical stimulation of the MoG results in a progressive decrease in excitatory junction potential (EJP) amplitude in flexor muscle fibres. Previous studies have demonstrated that l-arginine (l-Arg) modulates neuromuscular transmission. Since l-Arg is a precursor of nitric oxide (NO), we examined the possibility that NO may be involved in modulating neuromuscular transmission from MoGs to abdominal fast flexor muscles. The effect of a NO-generating compound, NOC7, was similar to that of l-Arg, reversibly decreasing the EJP amplitude mediated by the MoG. While NOC7 reduced the amplitude of the EJP, it induced no significant change in synaptic depression. In contrast, a scavenger of free radical NO, carboxy-PTIO, and an inhibitor of nitric oxide synthase, l-NAME, reversibly increased the EJP amplitude mediated by MoGs. Synaptic depression mediated by repetitive stimulation of MoGs at 1 Hz was partially blocked by bath application of l-NAME. Bath application of a NO scavenger, a NOS inhibitor and NO-generating compounds had no significant effects on the depolarisation of the muscle fibres evoked by local application of l-glutamate. The opposing effects on EJP amplitude of NOC7 and of carboxy-PTIO and l-NAME suggest that endogenous NO presynaptically modulates neuromuscular transmission and that it could play a prominent role at nerve terminals in eliciting MoG-mediated synaptic depression in the crayfish Procambarus clarkii.

Synaesthesia

2018 ◽  
Author(s):  
Polina Dimova
Keyword(s):  
Sensory System ◽  
Emotional Responses ◽  
High Pitch ◽  
Shared Experience ◽  
Perceptual Condition ◽  
Sensory Stimuli ◽  
Sensory Modalities ◽  
One To One ◽  
Over Time ◽  
Stimulation Of

Synaesthesia is the confusion or conflation of sensory modalities, where one sense is experienced or described in terms of another as in Charles Baudelaire’s simile "perfumes sweet as oboes, green as prairies." Synaesthesia captures an already existing tendency in language to blend the senses as in "sweet melody," "velvety voice," or "loud colors," and psychologists have conducted studies that show our shared experience of weak audiovisual associations between low pitch and darker colors, or high pitch and lighter colors. In a strictly neurological sense, synaesthesia is a perceptual condition in which the stimulation of one sensory system (for example, hearing) triggers sensations in another sensory system (for example, vision). Cross-sensory associations form one-to-one correspondences that are stable, delicately nuanced, and highly individual. For instance, a synaesthete may experience the timbre of violins as lime green, or the pitch A as burgundy. Synaesthetic associations occur as involuntary, automatic, and emotional responses to sensory stimuli. They persist throughout life and often aid memory: some synaesthetes reliably remember historical dates thanks to their color-to-number associations. The prevalence of synaesthesia has been contested over time, with varying ratios of synaesthetes to nonsynaesthetes of 1 in 2,000, 1 in 100 for colored letters and numbers in recent studies, and even 1 in 23 for all types of synaesthesia.

Brain stem responses to electrical stimulation of ventral vagal gastric fibers

1989 ◽  
Vol 257 (1) ◽  
pp. G24-G29
Author(s):  
W. D. Barber ◽  
C. S. Yuan
Keyword(s):  
Electrical Stimulation ◽  
Brain Stem ◽  
Time Of Arrival ◽  
Neuronal Responses ◽  
Proximal Stomach ◽  
Afferent Fibers ◽  
Sensory Modalities ◽  
The Mean ◽  
The Brain ◽  
Stimulation Of

The brain stem neuronal responses to electrical stimulation of gastric branches of the ventral vagal trunk serving the proximal stomach were localized and evaluated in anesthetized cats. The responses were equally distributed bilaterally in the region of nucleus solitarius in the caudal brain stem. The mean latency of the response was 289 +/- 46 (SD) ms, which translated into a conduction velocity of less than 1 m/s based on the distance between the stimulating and recording electrodes. The responses consisted of single and multiple spikes that showed slight variability in the latency, indicating orthodromic activation via a synapse in approximately 98% of the responses recorded. Forty two percent of the units tested showed evidence of convergence of input from vagal afferent fibers in different branches of the ventral vagal trunk that served the proximal stomach. The resultant activity pattern of the unitary response appeared to be the product of 1) the gastric sensory input or modality conveyed by the afferent source and 2) the time of arrival and diversity of modalities served by other gastric afferents impinging on the unit. This provides a mechanism capable of responding on the basis of specific sensory modalities that dynamically reflect ongoing events monitored and conveyed by other gastric afferents in the region.

scholarly journals Mechanisms of reflex bladder activation by pudendal afferents

2011 ◽  
Vol 300 (2) ◽  
pp. R398-R407 ◽  
Author(s):  
John P. Woock ◽  
Paul B. Yoo ◽  
Warren M. Grill
Keyword(s):  
Sympathetic Innervation ◽  
Bladder Volume ◽  
Nerve Transection ◽  
Hypogastric Nerve ◽  
Afferent Stimulation ◽  
Adrenergic Antagonist ◽  
Bladder Contraction ◽  
Dorsal Nerve ◽  
Frequency Of Stimulation ◽  
Stimulation Of

Activation of pudendal afferents can evoke bladder contraction or relaxation dependent on the frequency of stimulation, but the mechanisms of reflex bladder excitation evoked by pudendal afferent stimulation are unknown. The objective of this study was to determine the contributions of sympathetic and parasympathetic mechanisms to bladder contractions evoked by stimulation of the dorsal nerve of the penis (DNP) in α-chloralose anesthetized adult male cats. Bladder contractions were evoked by DNP stimulation only above a bladder volume threshold equal to 73 ± 12% of the distension-evoked reflex contraction volume threshold. Bilateral hypogastric nerve transection (to eliminate sympathetic innervation of the bladder) or administration of propranolol (a β-adrenergic antagonist) decreased the stimulation-evoked and distension-evoked volume thresholds by −25% to −39%. Neither hypogastric nerve transection nor propranolol affected contraction magnitude, and robust bladder contractions were still evoked by stimulation at volume thresholds below the distension-evoked volume threshold. As well, inhibition of distention-evoked reflex bladder contractions by 10 Hz stimulation of the DNP was preserved following bilateral hypogastric nerve transection. Administration of phentolamine (an α-adrenergic antagonist) increased stimulation-evoked and distension-evoked volume thresholds by 18%, but again, robust contractions were still evoked by stimulation at volumes below the distension-evoked threshold. These results indicate that sympathetic mechanisms contribute to establishing the volume dependence of reflex contractions but are not critical to the excitatory pudendal to bladder reflex. A strong correlation between the magnitude of stimulation-evoked bladder contractions and bladder volume supports that convergence of pelvic afferents and pudendal afferents is responsible for bladder excitation evoked by pudendal afferents. Further, abolition of stimulation-evoked bladder contractions following administration of hexamethonium bromide confirmed that contractions were generated by pelvic efferent activation via the pelvic ganglion. These findings indicate that pudendal afferent stimulation evokes bladder contractions through convergence with pelvic afferents to increase pelvic efferent activity.

Sensory Activation and Receptive Field Organization of the Lateral Giant Escape Neurons in Crayfish

2010 ◽  
Vol 104 (2) ◽  
pp. 675-684 ◽  
Author(s):  
Yen-Chyi Liu ◽  
Jens Herberholz
Keyword(s):  
Action Potential ◽  
Procambarus Clarkii ◽  
Receptive Fields ◽  
Sensory Information ◽  
Tactile Stimuli ◽  
Field Organization ◽  
Tail Flip ◽  
Receptive Field Organization ◽  
Sensory Activation ◽  
Stimulation Of

Crayfish ( Procambarus clarkii ) have bilateral pairs of giant interneurons that control rapid escape movements in response to predatory threats. The medial giant neurons (MGs) can be made to fire an action potential by visual or tactile stimuli directed to the front of the animal and this leads to an escape tail-flip that thrusts the animal directly backward. The lateral giant neurons (LGs) can be made to fire an action potential by strong tactile stimuli directed to the rear of the animal, and this produces flexions of the abdomen that propel the crayfish upward and forward. These observations have led to the notion that the receptive fields of the giant neurons are locally restricted and do not overlap with each other. Using extra- and intracellular electrophysiology in whole animal preparations of juvenile crayfish, we found that the receptive fields of the LGs are far more extensive than previously assumed. The LGs receive excitatory inputs from descending interneurons originating in the brain; these interneurons can be activated by stimulation of the antenna II nerve or the protocerebral tract. In our experiments, descending inputs alone could not cause action potentials in the LGs, but when paired with excitatory postsynaptic potentials elicited by stimulation of tail afferents, the inputs summed to yield firing. Thus the LG escape neurons integrate sensory information received through both rostral and caudal receptive fields, and excitatory inputs that are activated rostrally can bring the LGs' membrane potential closer to threshold. This enhances the animal's sensitivity to an approaching predator, a finding that may generalize to other species with similarly organized escape systems.

scholarly journals Mitochondrial Ca2+ Dynamics in MCU Knockout C. elegans Worms

2020 ◽  
Vol 21 (22) ◽  
pp. 8622
Author(s):  
Pilar Álvarez-Illera ◽  
Paloma García-Casas ◽  
Rosalba I Fonteriz ◽  
Mayte Montero ◽  
Javier Alvarez
Keyword(s):  
Cell Activation ◽  
Physiological Activity ◽  
Large Cell ◽  
Atp Production ◽  
Physiological Conditions ◽  
C Elegans ◽  
Neuronal Stimulation ◽  
Low Amplitude ◽  
Stimulation Of

Mitochondrial [Ca2+] plays an important role in the regulation of mitochondrial function, controlling ATP production and apoptosis triggered by mitochondrial Ca2+ overload. This regulation depends on Ca2+ entry into the mitochondria during cell activation processes, which is thought to occur through the mitochondrial Ca2+ uniporter (MCU). Here, we have studied the mitochondrial Ca2+ dynamics in control and MCU-defective C. elegans worms in vivo, by using worms expressing mitochondrially-targeted YC3.60 yellow cameleon in pharynx muscle. Our data show that the small mitochondrial Ca2+ oscillations that occur during normal physiological activity of the pharynx were very similar in both control and MCU-defective worms, except for some kinetic differences that could mostly be explained by changes in neuronal stimulation of the pharynx. However, direct pharynx muscle stimulation with carbachol triggered a large and prolonged increase in mitochondrial [Ca2+] that was much larger in control worms than in MCU-defective worms. This suggests that MCU is necessary for the fast mitochondrial Ca2+ uptake induced by large cell stimulations. However, low-amplitude mitochondrial Ca2+ oscillations occurring under more physiological conditions are independent of the MCU and use a different Ca2+ pathway.

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