scholarly journals Wing Hair Plates in Crickets: Physiological Characteristics and Connections with Stridulatory Motor Neurones

1983 ◽  
Vol 107 (1) ◽  
pp. 21-47 ◽  
Author(s):  
C.J.H. ELLIOTT
Keyword(s):  
Electrical Stimulation ◽  
Action Potentials ◽  
Viscous Drag ◽  
Behavioural Study ◽  
Wing Hair ◽  
Motor Neurones ◽  
Association Area ◽  
The Mean ◽  
Wing Folding ◽  
Stimulation Of

(1) Hairs in the subcostal hair plates of the wings of crickets have a high angular stiffness (5.5μNm rad1) when bent about their base. The mean threshold required to elicit action potentials is 15°. Viscous drag from air movements will not deflect the hairs sufficiently to excite them; this will only occur when the hair is bent by the opposite wing. (2) The hair sensillae project to the ventral association area of the mesothoracic ganglion, but the endings of the stridulatory motor neurones are all in dorsal or lateral neuropiles of the thoracic ganglia. (3) Electrical stimulation of the hair plates evokes reliable EPSPs in opener (M99), closer (M90) and wing folding (M85) motor neurones, after latencies of 4–20 ms, depending on the neurone. Properties of the hairs and motor neurones suggest that these EPSPs in the wing folding muscle (M85) and closer (M90) could play an important role in the control of wing position seen in recent behavioural study.

Electronmicroscopic and electrophysiological studies of the teat branch of the XIII thoracic nerve: relationship with lactation in the rat

1988 ◽  
Vol 118 (3) ◽  
pp. 471-483 ◽  
Author(s):  
L. M. Voloschin ◽  
E. Décima ◽  
J. H. Tramezzani
Keyword(s):  
Electrical Stimulation ◽  
Conduction Velocity ◽  
Action Potentials ◽  
Silent Period ◽  
High Amplitude ◽  
Milk Ejection ◽  
Nerve Activity ◽  
Thoracic Nerve ◽  
Myelinated Fibres ◽  
Stimulation Of

ABSTRACT Electrical stimulation of the XIII thoracic nerve (the 'mammary nerve') causes milk ejection and the release of prolactin and other hormones. We have analysed the route of the suckling stimulus at the level of different subgroups of fibres of the teat branch of the XIII thoracic nerve (TBTN), which innervates the nipple and surrounding skin, and assessed the micromorphology of the TBTN in relation to lactation. There were 844 ± 63 and 868 ± 141 (s.e.m.) nerve fibres in the TBTN (85% non-myelinated) in virgin and lactating rats respectively. Non-myelinated fibres were enlarged in lactating rats; the modal value being 0·3–0·4 μm2 for virgin and 0·4–0·5 μm2 for lactating rats (P > 0·001; Kolmogorov–Smirnov test). The modal value for myelinated fibres was 3–6 μm2 in both groups. The compound action potential of the TBTN in response to electrical stimulation showed two early volleys produced by the Aα- and Aδ-subgroups of myelinated fibres (conduction velocity rate of 60 and 14 m/s respectively), and a late third volley originated in non-myelinated fibres ('C') group; conduction velocity rate 1·4 m/s). Before milk ejection the suckling pups caused 'double bursts' of fibre activity in the Aδ fibres of the TBTN. Each 'double burst' consisted of low amplitude action potentials and comprised two multiple discharges (33–37 ms each) separated by a silent period of around 35 ms. The 'double bursts' occurred at a frequency of 3–4/s, were triggered by the stimulation of the nipple and were related to fast cheek movements visible only by watching the pups closely. In contrast, the Aα fibres of the TBTN showed brief bursts of high amplitude potentials before milk ejection. These were triggered by the stimulation of cutaneous receptors during gross slow sucking motions of the pup (jaw movements). Immediately before the triggering of milk ejection the mother was always asleep and a low nerve activity was recorded in the TBTN at this time. When reflex milk ejection occurred, the mother woke and a brisk increase in nerve activity was detected; this decreased when milk ejection was accomplished. In conscious rats the double-burst type of discharges in Aδ fibres was not observed, possibly because this activity cannot be detected by the recording methods currently employed in conscious animals. During milk ejection, action potentials of high amplitude were conveyed in the Aα fibres of the TBTN. During the treading time of the stretch reaction (SR), a brisk increase in activity occurred in larger fibres; during the stretching periods of the SR a burst-type discharge was again observed in slow-conducting afferents; when the pups changed nipple an abrupt increase in activity occurred in larger fibres. In summary, the non-myelinated fibres of the TBTN are increased in diameter during lactation, and the pattern of suckling-evoked nerve activity in myelinated fibres showed that (a) the double burst of Aδ fibres, produced by individual sucks before milk ejection, could be one of the conditions required for the triggering of the reflex, and (b) the nerve activity displayed during milk-ejection action may result, at least in part, from 'non-specific' stimulation of cutaneous receptors. J. Endocr. (1988) 118, 471–483

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.

Comparison of gene expression of 2-mo denervated, 2-mo stimulated-denervated, and control rat skeletal muscles

2005 ◽  
Vol 22 (2) ◽  
pp. 227-243 ◽  
Author(s):  
Tatiana Y. Kostrominova ◽  
Douglas E. Dow ◽  
Robert G. Dennis ◽  
Richard A. Miller ◽  
John A. Faulkner
Keyword(s):  
Gene Expression ◽  
Electrical Stimulation ◽  
Mrna Expression ◽  
Action Potentials ◽  
Skeletal Muscles ◽  
Microarray Study ◽  
Number Of Genes ◽  
Denervated Muscles ◽  
And Control ◽  
Stimulation Of

Loss of innervation in skeletal muscles leads to degeneration, atrophy, and loss of force. These dramatic changes are reflected in modifications of the mRNA expression of a large number of genes. Our goal was to clarify the broad spectrum of molecular events associated with long-term denervation of skeletal muscles. A microarray study compared gene expression profiles of 2-mo denervated and control extensor digitorum longus (EDL) muscles from 6-mo-old rats. The study identified 121 genes with increased and 7 genes with decreased mRNA expression. The expression of 107 of these genes had not been identified previously as changed after denervation. Many of the genes identified were genes that are highly expressed in skeletal muscles during embryonic development, downregulated in adults, and upregulated after denervation of muscle fibers. Electrical stimulation of denervated muscles preserved muscle mass and maximal force at levels similar to those in the control muscles. To understand the processes underlying the effect of electrical stimulation on denervated skeletal muscles, mRNA and protein expression of a number of genes, identified by the microarray study, was compared. The hypothesis was that loss of nerve action potentials and muscle contractions after denervation play the major roles in upregulation of gene expression in skeletal muscles. With electrical stimulation of denervated muscles, the expression levels for these genes were significantly downregulated, consistent with the hypothesis that loss of action potentials and/or contractions contribute to the alterations in gene expression in denervated skeletal muscles.

Electrical Stimulation of the Rat Lumbar Spine Induces Reflex Action Potentials in the Nerves to the Lower Abdomen

Spine ◽  
2000 ◽  
Vol 25 (4) ◽  
pp. 411-417 ◽  
Author(s):  
Yuzuru Takahashi ◽  
Jiro Hirayama ◽  
Yoshio Nakajima ◽  
Seiji Ohtori ◽  
Kazuhisa Takahashi
Keyword(s):  
Electrical Stimulation ◽  
Lumbar Spine ◽  
Action Potentials ◽  
Lower Abdomen ◽  
Reflex Action ◽  
Stimulation Of

scholarly journals Submicroscopic Changes of the Nerve Endings in the Adrenal Medulla after Stimulation of the Splanchnic Nerve

1957 ◽  
Vol 3 (4) ◽  
pp. 611-614 ◽  
Author(s):  
Eduardo De Robertis ◽  
Alberto Vaz Ferreira
Keyword(s):  
Electrical Stimulation ◽  
Electron Microscope ◽  
Adrenal Medulla ◽  
Synaptic Vesicles ◽  
Splanchnic Nerve ◽  
The Other ◽  
Nerve Endings ◽  
The Mean ◽  
Increased Activity ◽  
Stimulation Of

The nerve endings of the adrenal medulla of the rabbit were studied under the electron microscope in the normal condition and after prolonged electrical stimulation of the splanchnic nerve. With a stimulus of 100 pulses per second for 10 minutes, there is an increase in the number of synaptic vesicles in the nerve ending. The mean number is of 82.6 vesicles per square micron in the normal and of 132.7 per square micron in the stimulated glands. With a stimulus of 400 pulses per second for 10 minutes, there is a considerable depletion of synaptic vesicles and other changes occur in the nerve endings. The mean number of vesicles is of 29.2 per square micron. These results are interpreted as indicative of an increased activity of the ending in one case, and as a diminished activity and fatigue of the synaptic junction in the other.

scholarly journals Facial Nerve Schwannomas Mimicking as Vestibular Schwannomas

2017 ◽  
Vol 78 (04) ◽  
pp. 283-287
Author(s):  
Sean Wise ◽  
David Cohen ◽  
Jason Bell ◽  
Dennis Bojrab ◽  
Michael LaRouere ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Outcome Measures ◽  
Action Potentials ◽  
Internal Auditory Canal ◽  
Vestibular Schwannomas ◽  
Tumor Capsule ◽  
Spontaneous Action ◽  
The Mean ◽  
Spontaneous Action Potentials ◽  
Stimulation Of

Objective The objective of this study was to identify preoperative and intraoperative findings that may aid in distinguishing facial nerve schwannomas (FNS) from vestibular schwannomas (VSs), particularly in cases limited to the internal auditory canal (IAC) and cerebellopontine angle (CPA). Study Design This was a retrospective study. Setting This study was set at a Tertiary Referral Center. Patients Seventeen cases from October 2002 to July 2015 with an IAC/CPA mass presumed to be a VS who were found to have a FNS intraoperatively. Main Outcome Measures The main outcome measures included preoperative presentation, intraoperative findings, and subsequent intervention. Results Preoperative hearing loss and imbalance were seen in 70.5 and 64.7%, respectively. Suspicious intraoperative findings included: facial nerve incorporated intimately with the tumor capsule in 12 cases; spontaneous action potentials noted while drilling the bony IAC in 3 cases; and action potentials noted on stimulation of the entire tumor capsule in 10 cases. The mean long-term facial function was House–Brackmann grade II and the mean length of follow-up was 4.86 years. Conclusion FNSs are rare and may be difficult to distinguish from VS preoperatively. Surgical findings that should raise concern include spontaneous action potentials during drilling the bony IAC, absence of a plane of dissection between the facial nerve and tumor, or stimulation of the tumor capsule.

Two slow conduction systems co-ordinate shell-climbing behaviour in the sea anemone Calliactis parasitica

1976 ◽  
Vol 64 (2) ◽  
pp. 431-445
Author(s):  
I. D. McFarlane
Keyword(s):  
Electrical Stimulation ◽  
Low Frequency ◽  
Sensory Response ◽  
Pulse Interval ◽  
Nerve Net ◽  
Slow Conduction ◽  
Calliactis Parasitica ◽  
Climbing Behaviour ◽  
The Mean ◽  
Stimulation Of

1. Pulses in two slow conducting systems, the ectodermal SS 1 and the endodermal SS 2, were recorded during shell-climbing behaviour. The mean pulse interval of SS 1 pulses was 7–4 s and that of SS 2 pulses was 6-4 s. Activity in both systems may arise as a sensory response of tentacles to shell contact, but the SS 1 and SS 2 may not share the same receptors. 2. Electrical stimulation of the SS 1 and SS 2 together, at a frequency of 1 shock every 5 s, elicits shell-climbing behaviour in the absence of a shell. 3. Low-frequency nerve-net activity (about 1 pulse every 15 s) accompanies column bending during both normal and electrically elicited responses. This activity probably arises as a result of column bending and is not due to a sensory response to the shell.

scholarly journals Self-Motion Signals in Vestibular Nuclei Neurons Projecting to the Thalamus in the Alert Squirrel Monkey

2009 ◽  
Vol 101 (4) ◽  
pp. 1730-1741 ◽  
Author(s):  
Vladimir Marlinski ◽  
Robert A. McCrea
Keyword(s):  
Electrical Stimulation ◽  
Vertical Axis ◽  
Vestibular Nuclei ◽  
Head Movements ◽  
Stimulus Velocity ◽  
The Earth ◽  
The Mean ◽  
Self Motion ◽  
Head Rotations ◽  
Stimulation Of

Sixty vestibular nuclei neurons antidromically activated by electrical stimulation of the ventroposterior thalamus were recorded in two alert squirrel monkeys. The majority of these neurons were monosynaptically activated by vestibular nerve electrical stimulation. Forty-seven neurons responded to animal rotations around the earth-vertical axis; 16 of them also responded to translations in the horizontal plane. The mean sensitivity to 0.5-Hz rotations of 80°/s velocity was 0.40 ± 0.31 spikes·s−1·deg−1·s−1. Rotational responses were in phase with stimulus velocity. Sensitivities to 0.5-Hz translations of 0.1 g acceleration varied from 92.2 to 359 spikes·s−1· g−1 and response phases varied from 10.1° lead to −98° lag. The firing behavior in 28 neurons was studied during rotation of the whole animal, of the trunk, and voluntary and involuntary rotations of the head. Two classes of vestibulothalamic neurons were distinguished. One class of neurons generated signals related to movement of the head that were similar either when the head and trunk move together or when the head moves on the stationary trunk. A fraction of these neurons fired during involuntary head movements only. A second class of neurons generated signals related to movement of the trunk. They responded when the trunk moved alone or simultaneously with the head, but did not respond to head rotations while the trunk was stationary.

scholarly journals Morphologic changes in boar sperm nuclei with reduced disulfide bonds in electrostimulated porcine oocytes

Reproduction ◽  
2006 ◽  
Vol 131 (3) ◽  
pp. 603-611 ◽  
Author(s):  
Michiko Nakai ◽  
Naomi Kashiwazaki ◽  
Akiko Takizawa ◽  
Naoki Maedomari ◽  
Manabu Ozawa ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Blastocyst Stage ◽  
Blastocyst Formation ◽  
The Mean ◽  
Sperm Nuclei ◽  
Morphologic Changes ◽  
Number Of Cells ◽  
Stimulation Of ◽  
Nuclear Decondensation

In pigs, failure of sperm nuclear decondensation has been reported after injection into oocytes. We examined the effects of pretreating sperm heads with Triton X-100 (TX-100) and dithiothreitol (DTT) and of electrical stimulation of oocytes after sperm head injection on time-dependent morphologic changes in sperm nuclei andin vitrodevelopment to the blastocyst stage. In experiment 1, spermatozoa were pretreated with 1% TX-100 and 5 mM DTT (T + D) or not treated, and then injected intoin vitromatured oocytes. Electrical stimulation (1.5 kV/cm, 20 μs DC pulse) was applied to the oocytes 1 h after injection (stimulated group) or was not applied (unstimulated group). Some of the oocytes in each group were evaluated at hourly intervals until 10 h after injection for morphologic changes in the sperm nuclei. Unstimulated oocytes injected with untreated spermatozoa showed a delayed peak in the rate of nuclear decondensation (39.4–44.1%, 3–6 h after injection) compared with oocytes injected with T + D-treated spermatozoa (57.0% and 52.6%, 1 and 2 h, respectively). The rate of male pronucleus formation peaked 6 h after stimulation (by 40–60%) after injected oocytes had been stimulated with an electrical pulse, irrespective of whether or not the spermatozoa had been pretreated. In unstimulated oocytes, the rate of male pronucleus formation did not increase and stayed at the basal level (less than 20%) throughout the culture period, regardless of the sperm treatment. Thus, T + D treatment of spermatozoa did not affect completion of fertilization. In experiment 2, we evaluated the effects of electrical stimulation and sperm treatment with T + D on the rate of blastocyst formation and the mean number of cells per blastocyst. Oocytes stimulated after injection with either T + D-treated or untreated spermatozoa showed significantly higher percentages of blastocyst formation (24.8% and 27.1% respectively) than did unstimulated oocytes (1.1% and 4.1% for T + D-treated and untreated respectively;P< 0.01 by Duncan’s multiple-range test). The rate of blastocyst formation did not differ between the T + D-treated and untreated groups. The mean number of cells per blastocyst did not differ among any of the groups (14.0–29.4 cells). These results suggest that pretreatment of sperm with TX-100 and DTT shifted the timing of sperm nuclear decondensation forward. However, pronucleus formation and development to the blastocyst stagein vitrowere not improved by sperm treatment. Thus, electrical stimulation of injected oocytes enhancesin vitrodevelopment to the blastocyst stage in pigs.

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