scholarly journals Radiocalcium Release by Stimulated and Potassium-Treated Sartorius Muscles of the Frog

1960 ◽  
Vol 43 (3) ◽  
pp. 481-493 ◽  
Author(s):  
A. M. Shanes ◽  
C. P. Bianchi
Keyword(s):  
Electrical Stimulation ◽  
Time Course ◽  
Rana Pipiens ◽  
Calcium Release ◽  
Sartorius Muscle ◽  
Entry And Exit ◽  
Potassium Depolarization ◽  
Rate Of Escape ◽  
The Individual ◽  
Stimulation Of

Stimulation of frog (Rana pipiens) sartorius muscle accelerates release of Ca45, but only during the period of stimulation. No appreciable difference is obtained in the calcium released per impulse whether stimulation is at a rate of 20/sec. or 0.5/sec. However, prior stimulation may appreciably increase the loss per impulse. In unfatigued muscles, the minimum amount of calcium liberated during an isotonic twitch is estimated to be about that previously calculated to enter, viz. 0.2 µµmole/cm2. The time course of radiocalcium release during potassium depolarization depends on the nature of the contracture. When contracture is isometric, the rate of escape is doubled and declines only slowly; if isotonic, the rate is quadrupled but declines in a few minutes to a level maintained at about double that before potassium. The minimal calcium release during the first 10 minutes of potassium treatment is estimated to be about the same in both cases and about one-half to one-third the uptake. This, and especially the close equality of calcium entry and exit during electrical stimulation, are pointed out as not necessarily inconsistent with a transitory net entry of calcium, comparable to the influx, into restricted regions of the individual fibers.

The initiation of diving apnoea in the frog, Rana pipiens

1976 ◽  
Vol 64 (1) ◽  
pp. 25-38
Author(s):  
N. H. West ◽  
D. R. Jones
Keyword(s):  
Electrical Stimulation ◽  
Water Level ◽  
Rana Pipiens ◽  
Buccal Cavity ◽  
Respiratory Muscles ◽  
Normal Pattern ◽  
Water Head ◽  
Response To Water ◽  
Water Meniscus ◽  
Stimulation Of

1. Diving apnoea in Rana pipiens was initiated by submerging the external nares. As the water level was raised above the frog, both buccal and lung pressure increased by an amount corresponding to the water head. During submergence the external nares remained closed, although the apnoeic period was punctuated by ventilation movements which moved gas between the lungs and buccal cavity. 2. Bilateral section of the ophthalmic nerves did not alter the normal pattern of ventilation in air, although it often resulted in the intake of water into the buccal cavity on submergence. Introduction of water into the buccal cavity, either naturally as in denervates or by injection through a catheter in intact frogs, triggered sustained electromyographical activity in some respiratory muscles. 3. Electroneurograms recorded from the cut peripheral end of an ophthalmic nerve showed that receptors in the external narial region were stimulated by movement of a water meniscus across them. Activity could also be recorded in the ophthalmic nerve in response to water flow past the submerged nares. Punctate stimulation of the narial region confirmed that these receptors were mechanosensitive. 4. Bilateral electrical stimulation of the central ends of cut ophthalmic nerves in lightly anaesthetized frogs caused apnoea with a latency of less than 200 ms. The external nares remained closed throughout the period of stimulation although buccal pressure events, resembling underwater ventilation movements, occurred when stimulation was prolonged.

Preoptic Activation of Frog Mating Behavior

Behaviour ◽  
1967 ◽  
Vol 30 (2-3) ◽  
pp. 239-257 ◽  
Author(s):  
Robert S. Schmidt
Keyword(s):  
Electrical Stimulation ◽  
Mating Behavior ◽  
Rana Pipiens ◽  
Preoptic Area ◽  
Preoptic Nucleus ◽  
Bufo Americanus ◽  
Electrode Holder ◽  
Tree Frogs ◽  
Stimulation Of

AbstractThe effects of preoptic lesions on mating calling and mate orientation were studied in Rana pipiens and several species of tree frogs (Hylidae). Mating calling was evoked by electrical stimulation of the preoptic area of Rana pipiens and Bufo americanus. A new chronic electrode holder is described. It is concluded that the region of the dorsal magnocellular preoptic nucleus is needed for mate orientation and that the region of the ventral magnocellular preoptic nucleus is needed for mating calling. It is suggested that these preoptic regions may act mainly as activators of more posterior "centers". Mating calling may have evolved through the origin of connections between pre-existing preoptic activators and a pre-existing release calling "center", rather than through the origin of a new mating calling "center".

scholarly journals Active avoidance training of rats with experimental diabetes mellitus

1993 ◽  
Vol 39 (1) ◽  
pp. 48-50
Author(s):  
Yu. I. Zaraiskaya ◽  
Ye. A. Alexandrova ◽  
A. O. Lukashev ◽  
N. A. Shvyrkova
Keyword(s):  
Active Avoidance ◽  
Time Course ◽  
Avoidance Training ◽  
Experimental Diabetes ◽  
Experimental Diabetes Mellitus ◽  
Defense Behavior ◽  
Male Wistar Rats ◽  
Streptozotocin Induced Diabetes ◽  
The Individual ◽  
Stimulation Of

Specific features of training the rats in a new form of defense behavior in insulin deficiency in animal body were under study. Experiments were carried out with 51 male Wistar rats, 24 of these with streptozotocin-induced diabetes. The method of bilateral active avoidance with acoustic signal stimulation, followed by electric stimulation of the skin, was employed. The curves of training, reflecting the time course of the number of effective behavioral acts, were analyzed, and the parameters of the shape of the individual curves of training estimated to classify the animals, making use of analysis of factors. A significant variability of the examined individual parameters of training was associated with the absence of noticeable differences in the approximated results of examinations of intact and streptozotocin-treated rats. Analysis of factors helped single out a group of rats with streptozotocin induced diabetes among the groups of animals that were characterized by similar training parameters, that could sooner learn a new habit after a longer latent period as against intact animals.

Pain suppression induced by electrical stimulation of the pontine parabrachial region

1985 ◽  
Vol 62 (3) ◽  
pp. 397-407 ◽  
Author(s):  
Antonio A. F. DeSalles ◽  
Yoichi Katayama ◽  
Donald P. Becker ◽  
Ronald L. Hayes
Keyword(s):  
Electrical Stimulation ◽  
Time Course ◽  
Low Frequency ◽  
Cholinergic Stimulation ◽  
Technical Problems ◽  
Physiological Functions ◽  
Content Type ◽  
Analgesic Effects ◽  
Stimulation Parameters ◽  
Stimulation Of

✓ Cholinergic stimulation by microinjection of drugs into a region surrounding the lateral half of the brachium conjunctivum selectively produces a non-opiate form of pain suppression in the cat. Since this suppression does not appear to involve neural systems that mediate morphine analgesia, stimulation of this pontine parabrachial region (PBR) may potentially be useful for control of human pain resistant or tolerant to opiate treatment. Because of technical problems associated with the clinical use of microinjection techniques in the human brain, we investigated whether electrical stimulation of the PBR can produce pain suppression similar to pain suppression produced by cholinergic stimulation. The results indicate that electrical stimulation of an area generally corresponding to the PBR can also produce significant pain suppression. Although the PBR is a region previously implicated in a variety of behavioral and physiological functions, the stimulation parameters that produce maximal pain suppressive effects (namely, low frequency and relatively low intensity) were not associated with noticeable changes in such functions. The prolonged onset period and persistent analgesic effects outlasting the period of stimulation — features that have been reported in other studies of brain stimulation-produced pain suppression — were observed in the present study. The time course of pain suppression did not parallel other changes in behavioral and physiological functions. These data indicate that electrical stimulation of the PBR, under certain stimulation parameters, can activate previously demonstrated neural populations related to pain suppression without affecting neural elements contributing to other behavioral or physiological functions. The authors suggest that electrical stimulation of the PBR may be clinically applicable for treatment of human pain.

Plasticity of Bat's Central Auditory System Evoked by Focal Electric Stimulation of Auditory and/or Somatosensory Cortices

2001 ◽  
Vol 85 (3) ◽  
pp. 1078-1087 ◽  
Author(s):  
Xiaofeng Ma ◽  
Nobuo Suga
Keyword(s):  
Electrical Stimulation ◽  
Somatosensory Cortex ◽  
Cortical Neurons ◽  
Electric Stimulation ◽  
Time Course ◽  
Recovery Period ◽  
Acoustic Stimulus ◽  
Acoustic Parameter ◽  
Response Curves ◽  
Stimulation Of

Recent findings indicate that the corticofugal system would play an important role in cortical plasticity as well as collicular plasticity. To understand the role of the corticofugal system in plasticity, therefore, we studied the amount and the time course of plasticity in the inferior colliculus (IC) and auditory cortex (AC) evoked by focal electrical stimulation of the AC and also the effect of electrical stimulation of the somatosensory cortex on the plasticity evoked by the stimulation of the AC. In adult big brown bats ( Eptesicus fuscus), we made the following major findings. 1) Electric stimulation of the AC evokes best frequency (BF) shifts, i.e., shifts in frequency-response curves of collicular and cortical neurons. These BF shifts start to occur within 2 min, reach a maximum (or plateau) at 30 min, and then recover ∼180 min after a 30-min-long stimulus session. When the stimulus session is lengthened from 30 to 90 min, the plateau lasts ∼60 min, but BF shifts recover ∼180 min after the session. 2) The electric stimulation of the somatosensory cortex delivered immediately after that of the AC, as in fear conditioning, evokes a dramatic lengthening of the recovery period of the cortical BF shifts but not that of the collicular BF shift. The electric stimulation of the somatosensory cortex delivered before that of the AC, as in backward conditioning, has no effect on the collicular and cortical BF shifts. 3) Electric stimulation of the AC evokes BF shifts not only in the ipsilateral IC and AC but also in the contralateral IC and AC. BF shifts are smaller in amount and shorter in recovery time for contralateral collicular and cortical neurons than for ipsilateral ones. Our findings support the hypothesis that the AC and the corticofugal system have an intrinsic mechanism for reorganization of the IC and AC, that the reorganization is highly specific to a value of an acoustic parameter (frequency), and that the reorganization is augmented by excitation of nonauditory sensory cortex that makes the acoustic stimulus behaviorally relevant to the animal through associative learning.

The co-ordination of the protective retraction of coral polyps

1957 ◽  
Vol 240 (675) ◽  
pp. 495-529 ◽  
Keyword(s):  
Electrical Stimulation ◽  
Electrical Stimulus ◽  
Simple Theory ◽  
Conducting System ◽  
Common Theme ◽  
Single Shock ◽  
Working Model ◽  
Successive Stimulus ◽  
The Individual ◽  
Stimulation Of

The responses to electrical stimulation of a number of alcyonarian, zoanthid and madreporarian corals are described. All groups studied except gorgonids show extensive coordination over the colony. In Sarcophyton (Alcyonacea) the response is typically local at first but eventually a wave of polyp retraction can be made to spread over the colony. The astraeid corals and the alcyonarian Tubipora have over the whole colony a through-conducting system which has refractory and neuromuscular properties similar to those found in the mesenteries of actinians. In the zoanthid Palythoa successive shocks produce excitation which spreads progressively farther across the colony at each shock for as many as fifty shocks at two-second intervals. The perforate corals , Acropora, Goniopora and Porites respond to a single shock by a co-ordinated retraction of many polyps. Except in Acropora , it is characteristic of the perforate corals studied that stimulation at one point never spreads over the whole colony no matter how many stimuli are applied. The responses of the individual polyps of many corals, including Fungia , are described, and in all there is a similarity to the column, disk and tentacle responses already known in actinians, e.g. Calliactis . The concept of interneural facilitation has been analyzed by use of a working model which shows that the simple theory is inadequate as an explanation of transmission between polyps of certain species because the predicted transmission distances are either too variable or too small compared with the actual distances observed at the first electrical stimulus of the animal. The properties of the co-ordinating systems between the polyps of the various groups of corals have been considered as variations on a common theme, conduction between units which form a network. The various stages from poor co-ordination, through progressive spread at each successive stimulus, to a through-conducting condition have been interpreted as a reflexion of increasing probability of transmission from one all-or-nothing unit of the pathway to the next unit in a population of a large number of units, only a proportion of which may be active at any one time. The units may be interpreted as neurones, as is probable in parts of a single polyp, or as small regions such as polyps within which there is normally through-conduction at the first stimulus.

Observation of Velopharyngeal Closure Patterns following Isolated Stimulation of Levator Veli Palatini and Pharyngeal Constrictor Muscles

1996 ◽  
Vol 33 (4) ◽  
pp. 273-276 ◽  
Author(s):  
Mikihiko Kogo ◽  
Munehiro Hamaguchi ◽  
Tokuzo Matsuya
Keyword(s):  
Electrical Stimulation ◽  
Motor Nerve ◽  
Lateral Wall ◽  
Vertical Movement ◽  
Levator Veli Palatini ◽  
Velopharyngeal Closure ◽  
The Individual ◽  
Pharyngeal Constrictor Muscles ◽  
Peripheral Motor ◽  
Stimulation Of

This study, using mongrel dogs, showed the individual movements caused by the levator veli palatini muscle (LVP) and pharyngeal constrictor (PC) contraction, induced by electrical stimulation to each peripheral motor nerve. Each bilateral peripheral motor nerve of the LVP and PC muscles was isolated and stimulated electrically to induce the individual contraction of bilateral LVP and PC muscles. The movements were visualized by use of a fiberscope. Vertical movement of the middle soft palate was observed mainly at LVP contraction. Circular closure in the posterior region of the velopharynx was induced by contraction of the PC muscle. The posterior and lateral wall movements clearly occurred following PC contraction.

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