Effects of low-frequency stimulation of the superior colliculus on spontaneous and visually guided saccades

1993 ◽  
Vol 69 (3) ◽  
pp. 953-964 ◽  
Author(s):  
P. W. Glimcher ◽  
D. L. Sparks
Keyword(s):  
Superior Colliculus ◽  
Time Course ◽  
Low Frequency ◽  
Arbitrary Point ◽  
Visually Guided ◽  
Spontaneous Movements ◽  
Low Frequency Stimulation ◽  
Frequency Stimulation ◽  
Stimulation Current ◽  
Stimulation Of

1. The first experiment of this study determined the effects of low-frequency stimulation of the monkey superior colliculus on spontaneous saccades in the dark. Stimulation trains, subthreshold for eliciting short-latency fixed-vector saccades, were highly effective at biasing the metrics (direction and amplitude) of spontaneous movements. During low-frequency stimulation, the distribution of saccade metrics was biased toward the direction and amplitude of movements induced by suprathreshold stimulation of the same collicular location. 2. Low-frequency stimulation biased the distribution of saccade metrics but did not initiate movements. The distribution of intervals between stimulation onset and the onset of the next saccade did not differ significantly from the distribution of intervals between an arbitrary point in time and the onset of the next saccade under unstimulated conditions. 3. Results of our second experiment indicate that low-frequency stimulation also influenced the metrics of visually guided saccades. The magnitude of the stimulation-induced bias increased as stimulation current or frequency was increased. 4. The time course of these effects was analyzed by terminating stimulation immediately before, during, or after visually guided saccades. Stimulation trains terminated at the onset of a movement were as effective as stimulation trains that continued throughout the movement. No effects were observed if stimulation ended 40–60 ms before the movement began. 5. These results show that low-frequency collicular stimulation can influence the direction and amplitude of spontaneous or visually guided saccades without initiating a movement. These data are compatible with the hypothesis that the collicular activity responsible for specifying the horizontal and vertical amplitude of a saccade differs from the type of collicular activity that initiates a saccade.

Robust Changes of Afferent-Induced Excitation in the Rat Spinal Dorsal Horn After Conditioning High-Frequency Stimulation

2000 ◽  
Vol 83 (4) ◽  
pp. 2412-2420 ◽  
Author(s):  
Hiroshi Ikeda ◽  
Tatsuya Asai ◽  
Kazuyuki Murase
Keyword(s):  
Dorsal Horn ◽  
High Frequency ◽  
Low Frequency ◽  
Single Pulse ◽  
High Frequency Stimulation ◽  
Neuronal Excitation ◽  
Low Frequency Stimulation ◽  
Frequency Stimulation ◽  
Stimulation Of

We investigated the neuronal plasticity in the spinal dorsal horn and its relationship with spinal inhibitory networks using an optical-imaging method that detects neuronal excitation. High-intensity single-pulse stimulation of the dorsal root activating both A and C fibers evoked an optical response in the lamina II (the substantia gelatinosa) of the dorsal horn in transverse slices of 12- to 25-day-old rat spinal cords stained with a voltage-sensitive dye, RH-482. The optical response, reflecting the net neuronal excitation along the slice-depth, was depressed by 28% for more than 1 h after a high-frequency conditioning stimulation of A fibers in the dorsal root (3 tetani of 100 Hz for 1 s with an interval of 10 s). The depression was not induced in a perfusion solution containing an NMDA antagonist,dl-2-amino-5-phosphonovaleric acid (AP5; 30 μM). In a solution containing the inhibitory amino acid antagonists bicuculline (1 μM) and strychnine (3 μM), and also in a low Cl−solution, the excitation evoked by the single-pulse stimulation was enhanced after the high-frequency stimulation by 31 and 18%, respectively. The enhanced response after conditioning was depotentiated by a low-frequency stimulation of A fibers (0.2–1 Hz for 10 min). Furthermore, once the low-frequency stimulation was applied, the high-frequency conditioning could not potentiate the excitation. Inhibitory transmissions thus regulate the mode of synaptic plasticity in the lamina II most likely at afferent terminals. The high-frequency conditioning elicits a long-term depression (LTD) of synaptic efficacy under a greater activity of inhibitory amino acids, but it results in a long-term potentiation (LTP) when inhibition is reduced. The low-frequency preconditioning inhibits the potentiation induction and maintenance by the high-frequency conditioning. These mechanisms might underlie robust changes of nociception, such as hypersensitivity after injury or inflammation and pain relief after electrical or cutaneous stimulation.

Low-frequency stimulation of the ventral hippocampus facilitates extinction of contextual fear

2013 ◽  
Vol 101 ◽  
pp. 39-45 ◽  
Author(s):  
Carine Cleren ◽  
Isabelle Tallarida ◽  
Emilie Le Guiniec ◽  
François Janin ◽  
Ophélie Nachon ◽  
...  
Keyword(s):  
Low Frequency ◽  
Ventral Hippocampus ◽  
Contextual Fear ◽  
Low Frequency Stimulation ◽  
Frequency Stimulation ◽  
Stimulation Of

Slow cardioacceleration mediated by noncholinergic transmission in the stellate ganglion of the cat

1988 ◽  
Vol 66 (8) ◽  
pp. 1066-1074 ◽  
Author(s):  
Manjit Bachoo ◽  
Ehud Isacoff ◽  
Canio Polosa
Keyword(s):  
Heart Rate ◽  
Rate Increase ◽  
Stellate Ganglion ◽  
Low Frequency ◽  
Low Frequency Stimulation ◽  
Frequency Stimulation ◽  
Preganglionic Stimulation ◽  
Slow Onset ◽  
Inferior Cardiac Nerve ◽  
Stimulation Of

In C1-spinal, pentobarbital-anaesthetized or anemically decerebrated cats, the preganglionic input to the acutely decentralized right stellate ganglion was stimulated with 10- to 30-s trains at 20–40 Hz. Electrical stimulation consistently produced an increase in heart rate in the presence of blocking doses of hexamethonium and atropine or after depletion of acetylcholine from the preganglionic axons by prolonged low frequency stimulation in the presence of hemicholinium. The increase in heart rate had a delayed slow onset, lasted several minutes, and was abolished by propranolol or by section of the inferior cardiac nerve. The magnitude and duration of the heart rate increase were related to intensity, frequency, and duration of preganglionic stimulation. The response to stimulation of a given white ramus was progressively attenuated, and eventually irreversibly lost, during prolonged continuous stimulation of that ramus, while the response to stimulation of a different unstimulated ramus was unchanged. We conclude that the slow cardioacceleration results from a slow and prolonged excitation of postganglionic neurons by a noncholinergic transmitter released by the preganglionic axons.

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