Presynaptic inhibition of transmission from identified interneurons in locust central nervous system

1981 ◽  
Vol 45 (3) ◽  
pp. 501-515 ◽  
Author(s):  
K. G. Pearson ◽  
C. S. Goodman
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Electrical Stimulation ◽  
Action Potentials ◽  
Presynaptic Inhibition ◽  
Auditory Stimuli ◽  
Movement Detector ◽  
Intracellular Recordings ◽  
Contralateral Movement ◽  
Stimulation Of

1. Intracellular recordings near the output terminals of an identified interneuron (the descending contralateral movement detector, DCMD) in the locust revealed the occurrence of depolarizing synaptic potentials. These presynaptic depolarizing potentials were evoked by spikes in both DCMDs, by auditory stimuli, and by electrical stimulation of the pro- to mesothoracic connectives. The occurrence of the depolarizing potentials decreased the amplitude of the action potentials close to the output terminals. 2. The stimuli that produced depolarizing potentials in the presynaptic terminals reduced the amplitude of the monosynaptic excitatory postsynaptic potentials evoked by the DCMDs in identified follower interneurons. We conclude that at least part of this reduction in transmission from the DCMDs results from presynaptic inhibition and that the presynaptic inhibition is related to a reduction in the amplitude of the presynaptic action potentials. 3. We propose that the function of the presynaptic inhibition of the DCMDs is to ensure that the interneurons triggering a jump are never activated by the DCMDs in the absence of proprioceptive signals from the legs indicating the animal's readiness to jump.

scholarly journals The Effects of Curare in the Cockroach

1970 ◽  
Vol 52 (3) ◽  
pp. 593-601
Author(s):  
K. J. FRIEDMAN ◽  
A. D. CARLSON
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Electrical Stimulation ◽  
Action Potential ◽  
Nerve Cord ◽  
Action Potentials ◽  
Periplaneta Americana ◽  
Sensory Motor ◽  
Giant Fibres ◽  
Stimulation Of

1. The study of insect curarization in the cockroach, Periplaneta americana, has been continued. The application of curare solution (0.032 M dTC) to the nerve cord produced blockage of action-potential conduction in the giant fibres lying within the nerve cord. 2. The application of curare solution to the cerci prevented the recording of action potentials from the cercal nerves of the organism. Application of dTC to the cercal nerve-A6 region of the cockroach prevented giant fibres from responding to electrical stimulation of the cercal nerves. These results are interpreted as indicating that curare blocks the conduction of action potentials in the cercal nerve. 3. It is proposed that curare can induce blockage of conduction in sensory, motor and central nervous system fibres. It is further proposed that this blockage of conduction is the mechanism of insect curarization. 4. The results of previous reports concerned with insect curarization are re-interpreted in view of the proposal. Several of the conflicts in these reports are resolved by the proposal that blockage of conduction is the mechanism of insect curarization.

scholarly journals Therapeutic electrical stimulation of the central nervous system

2005 ◽  
Vol 328 (2) ◽  
pp. 177-186 ◽  
Author(s):  
Alim-Louis Benabid ◽  
Bradley Wallace ◽  
John Mitrofanis ◽  
Celine Xia ◽  
Brigitte Piallat ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Electrical Stimulation ◽  
The Central Nervous System ◽  
Stimulation Of

Motivational and Perceptual Aspects of Subcortical Stimulation in Cats

1958 ◽  
Vol 194 (2) ◽  
pp. 427-432 ◽  
Author(s):  
Harold C. Nielson ◽  
Robert W. Doty ◽  
Lester T. Rutledge
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Electrical Stimulation ◽  
Minute Period ◽  
The Press ◽  
The Central Nervous System ◽  
Subcortical Stimulation ◽  
To Receive ◽  
Central Stimulation ◽  
Stimulation Of

Reports of others that animals will seek electrical stimulation of certain regions of the central nervous system are confirmed. A method is presented whereby these ‘motivational’ aspects of central stimulation can be analyzed and shown to be capable of change by training and to have a different threshold from the animal's ‘perception’ of this stimulation. Cats were trained to press a bar to receive pellets of meat. When each bar-press was accompanied by stimulation through electrodes implanted in the caudate nucleus or anterior hypothalamus, the animals continued pressing. If the press was paired with stimulation of the septal or habenular regions, pressing was abolished. Foot-shock paired with pressing also produced avoidance but pairing with a startling buzzer did not. Caudatal stimulation of 0.2 ma, 50/sec., 2-msec. pulses, was adequate as conditional stimulus to establish conditioned foreleg flexions to avoid an electric shock. Subsequent to the latter training two animals would no longer press the bar if pressing resulted in caudatal stimulation. Other cats would press as often as 1000 times in a 20-minute period to obtain caudatal stimulation if it were allowed at rapid rates and intensities five times that required to evoke conditioned flexion reflexes. The evidence suggests that avidity develops for stimulation of certain neural structures only if the stimulus is adequate to initiate some form of excessive, seizure-like activity.

scholarly journals A Movement Generated in the Peripheral Nervous System: Rhythmic Flexion by Autotomized Legs of the Stick Insect Cuniculina Impigra

1984 ◽  
Vol 111 (1) ◽  
pp. 191-199
Author(s):  
U. BÄSSLER
Keyword(s):  
Nervous System ◽  
Electrical Stimulation ◽  
Peripheral Nervous System ◽  
Related Species ◽  
Action Potentials ◽  
Small Diameter ◽  
Stick Insect ◽  
Muscle Twitch ◽  
Single Motor ◽  
Stimulation Of

Autotomized legs of the stick insect Cuniculina impigra bend rapidly and rhythmically at the femur-tibia joint. These flexions occur at a frequency 1–6 Hz immediately after autotomy and decrease in frequency and amplitude with time. Each flexion is produced by a burst of 1–14 action potentials in a single motor axon of the flexor tibiae muscle (bursting axon). These rhythmic discharges are generated in a very restricted part of the crural nerve, which contains the bursting axon, close to the autotomy point and appear whenever the nerve is cut in the immediate vicinity of this generator region. Rhythmic flexion can also be elicited by electrical stimulation of the crural nerve. The bursting axon is of small diameter. It innervates all or most of flexor tibiae muscle in which it produces relatively large EPSPs. Each EPSP elicits one muscle twitch. These fuse into a brief tetanus, whose amplitude is proportional to the number of spikes in a burst. Each tetanus produces one flexion. This behaviour does not occur in the autotomized legs of several related species.

The Neurological Basis of the Locomotory Rhythm in the Spinal Dogfish (Scyllium Canicula, Acanthias Vulgaris)

1946 ◽  
Vol 23 (2) ◽  
pp. 162-176 ◽  
Author(s):  
H. W. LISSMANN
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Electrical Stimulation ◽  
Posterior Half ◽  
Automatic Activity ◽  
Dorsal Roots ◽  
The Central Nervous System ◽  
Stimulation Of

Some of the more striking effects of de-afferentation in the spinal dogfish are diagrammatically represented in Fig. 13. 1. The persistent locomotory rhythm of a spinal dogfish depends upon afferent excitation. If all afferent excitation is cut off by severance of all dorsal roots, the rhythm is abolished (Fig. 13, 1). 2. The rhythm clearly emerges when about half the number of all the dorsal roots is transected, irrespective whether the anterior or the posterior half of the animal be de-afferentated (Fig. 13, 2 and 3), or whether complete unilateral de-afferentation is executed (Fig. 13, 4). 3. Extensively de-afferentated preparations may exhibit swimming movements after exteroceptive stimulation. These swimming movements do not persist. 4. Preparations de-afferentated except for the tail exhibit after exteroceptive stimulation a static reflex posture. 5. The de-afferentated musculature takes part in both tonic and rhythmic responses as long as it is connected through the spinal cord with normally innervated musculature. 6. In response to electrical stimulation applied to the cord of a spinal dogfish two distinct types of rhythmic response have been evoked. 7. No rhythmic responses have bee obtained through electrical stimulation of the spinal cord in completely de-afferentated preparations. 8. No evidence has been found in support of the view that the swimming rhythm emanates through a spontaneous, automatic activity from the central nervous system.

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