Effect of stimulation of the sensomotor cortex on the firing pattern of bulbar cardiovascular neurons during myocardial ischemia

1987 ◽  
Vol 104 (3) ◽  
pp. 1177-1180
Author(s):  
G. I. Kositskii ◽  
S. D. Mikhailova ◽  
S. L. Gorozhanin ◽  
T. M. Semushkina
Keyword(s):  
Myocardial Ischemia ◽  
Firing Pattern ◽  
Sensomotor Cortex ◽  
Cardiovascular Neurons ◽  
Stimulation Of

Medullary substrate and differential cardiovascular responses during stimulation of specific acupoints

2004 ◽  
Vol 287 (4) ◽  
pp. R852-R862 ◽  
Author(s):  
Stephanie C. Tjen-A-Looi ◽  
Peng Li ◽  
John C. Longhurst
Keyword(s):  
Median Nerve ◽  
Neuronal Activity ◽  
Radial Nerve ◽  
Cardiovascular Responses ◽  
Reflex Responses ◽  
Superficial Radial Nerve ◽  
Cardiovascular Reflex ◽  
Cardiovascular Neurons ◽  
Change In Mean ◽  
Stimulation Of

Electroacupuncture (EA) at P5–P6 acupoints overlying the median nerve reduces premotor sympathetic cardiovascular neuronal activity in the rostral ventral lateral medulla (rVLM) and visceral reflex pressor responses. In previous studies, we have noted different durations of influence of EA comparing P5–P6 and S36–S37 acupoints, suggesting that point specificity may exist. The purpose of this study was to evaluate the influence of stimulating P5–P6 (overlying the median nerve), LI4–L7 (overlying branches of the median nerve and the superficial radial nerve), LI6–LI7 (overlying the superficial radial nerve), LI10–LI11 (overlying the deep radial nerves), S36–S37 (overlying the deep peroneal nerves), or K1–B67 (overlying terminal branches of the tibial nerves) specific acupoints, overlying deep and superficial somatic nerves, on the excitatory cardiovascular reflex and rVLM responses evoked by stimulation of chemosensitive receptors in the cat's gallbladder with bradykinin (BK) or direct splanchnic nerve (SN) stimulation. We observed point-specific differences in magnitude and duration of EA inhibition between P5–P6 or LI10–LI11 and LI4–L7 or S36–S37 in responses to 30-min stimulation with low-frequency, low-current EA. EA at LI6–LI7 and K1–B67 acupoints as well as direct stimulation of the superficial radial nerve did not cause any cardiovascular or rVLM neuronal effects. Cardiovascular neurons in the rVLM, a subset of which were classified as premotor sympathetic cells, responded to brief (30 s) stimulation of the SN as well as acupoints P5–P6, LI10–LI11, LI4–L7, S36–S37, LI6–LI7, or K1–B67, or underlying somatic pathways in a fashion similar to the reflex responses. In fact, we observed a significant linear relationship ( r2 = 0.71) between the evoked rVLM response and reflex change in mean arterial blood pressure. In addition, EA stimulation at P5–P6 and LI4–L7 decreased rVLM neuronal activity by 41 and 12%, respectively, for >1 h, demonstrating that prolonged input into the medulla during stimulation of somatic nerves, depending on the degree of convergence, leads to more or less inhibition of activity of these cardiovascular neurons. Thus EA at acupoints overlying deep and superficial somatic nerves leads to point-specific effects on cardiovascular reflex responses. In a similar manner, sympathetic cardiovascular rVLM neurons that respond to both visceral (reflex) and somatic (EA) nerve stimulation manifest graded responses during stimulation of specific acupoints, suggesting that this medullary region plays a role in site-specific inhibition of cardiovascular reflex responses by acupuncture.

Inhibition of rostral VLM by baroreceptor activation is relayed through caudal VLM

1990 ◽  
Vol 258 (5) ◽  
pp. R1271-R1278 ◽  
Author(s):  
S. K. Agarwal ◽  
A. J. Gelsema ◽  
F. R. Calaresu
Keyword(s):  
Kynurenic Acid ◽  
Cardiac Cycle ◽  
Pressor Response ◽  
Inhibitory Response ◽  
Firing Frequency ◽  
Ventrolateral Medulla ◽  
Cardiovascular Neurons ◽  
Baroreceptor Activation ◽  
Acid Administration ◽  
Stimulation Of

Experiments were done to test the hypothesis that inhibition of neurons in the rostral ventrolateral medulla (RVLM) elicited by stimulation of the nucleus tractus solitarii (NTS) is relayed through the caudal ventrolateral medulla (CVLM). We recorded activity from 56 spontaneously firing units in the right RVLM of urethan-anesthetized and artificially ventilated rats. Eleven of these units were classified as cardiovascular neurons, because they were silenced by baroreceptor activation (1-3 micrograms phenylephrine iv) and showed rhythmicity of their spontaneous activity in synchrony with the cardiac cycle. Single pulses (0.1 ms, 30-75 microA) delivered 1/s to depressor sites in the ipsilateral NTS inhibited the activity of all these cardiovascular neurons. Microinjection of the glutamate antagonist kynurenic acid (0.15 M, 50 nl) into the ipsilateral CVLM blocked the inhibitory response of RVLM units to the administration of phenylephrine and increased the firing frequency of cardiovascular neurons in the RVLM by 43%. Moreover, kynurenic acid administration attenuated the inhibitory response of cardiovascular neurons in the RVLM to NTS stimulation. Finally, stimulation of the NTS that elicited depressor responses under control conditions produced a pressor response after kynurenic acid administration. The remaining 45 RVLM neurons were barosensitive but lacked cardiac cycle-related rhythmicity. These results provide direct evidence for the existence of a tonic inhibitory pathway from NTS to RVLM that is relayed through the CVLM probably by a glutamatergic projection from NTS to CVLM.

Behavior of upper cervical inspiratory propriospinal neurons during fictive vomiting

1991 ◽  
Vol 65 (6) ◽  
pp. 1492-1500 ◽  
Author(s):  
S. Nonaka ◽  
A. D. Miller
Keyword(s):  
Firing Pattern ◽  
Impulse Activity ◽  
Abdominal Muscle ◽  
Lateral Funiculus ◽  
Upper Cervical ◽  
Spinal Segments ◽  
Propriospinal Neurons ◽  
Lumbar Cord ◽  
Stimulation Of

1. The role of upper cervical inspiratory (UCI)-modulated neurons in respiratory muscle control during vomiting was examined by recording the impulse activity of these neurons during fictive vomiting in decerebrate, paralyzed cats. Fictive vomiting was identified by a characteristic series of bursts of coactivation of phrenic and abdominal muscle nerves, elicited either by electrical stimulation of supradiaphragmatic vagal nerve afferents or by emetic drugs, which would be expected to produce expulsion of gastric contents in nonparalyzed animals. 2. Data were recorded from 43 propriospinal UCI neurons, located in the C1-C3 spinal segments near the border of the intermediate gray matter and lateral funiculus, which were antidromically activated with floating pin electrodes placed in the ipsilateral lateral funiculus, usually at T1-T3. Some cells (9/21 tested) were also activated from the upper lumbar cord (L1). During respiration, most neurons (n = 40) had an augmenting discharge pattern during inspiration. In addition, more than one-half (55%) fired tonically during the remainder of the respiratory cycle. About 40% of UCI neurons showed variations in their firing pattern during the noninspiratory portion of respiration. These latter two properties of UCI neurons were not observed in dorsal and ventral respiratory group (DRG and VRG-, respectively) bulbospinal inspiratory (I) neurons previously recorded under similar conditions. 3. During fictive vomiting, the firing pattern of most UCI neurons fell into one of three main categories. More than one-half (53%) were active in phase with bursts of phrenic discharge and were thus classified as Active-type cells.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Distributed Phase Oscillatory Excitation Efficiently Produces Attractors Using Spike Timing Dependent Plasticity

2020 ◽  
Author(s):  
Eric C. Wong
Keyword(s):  
Oscillation Frequency ◽  
Firing Pattern ◽  
Spike Timing ◽  
Spiking Neurons ◽  
Driving Frequency ◽  
Spike Timing Dependent Plasticity ◽  
Dependent Plasticity ◽  
Periodic Stimulation ◽  
The Brain ◽  
Stimulation Of

ABSTRACTThe brain is thought to represent information in the form of activity in distributed groups of neurons known as attractors, but it is not clear how attractors are formed or used in processing. We show here that in a randomly connected network of simulated spiking neurons, periodic stimulation of neurons with distributed phase offsets, along with standard spike timing dependent plasticity (STDP), efficiently creates distributed attractors. These attractors may have a consistent ordered firing pattern, or become disordered, depending on the conditions. We also show that when two such attractors are stimulated in sequence, the same STDP mechanism can create a directed association between them, forming the basis of an associative network. We find that for an STDP time constant of 20ms, the dependence of the efficiency of attractor creation on the driving frequency has a broad peak centered around 8Hz. Upon restimulation, the attractors selfoscillate, but with an oscillation frequency that is higher than the driving frequency, ranging from 10-100Hz.

Effect of the Stimulation of Sensory Inputs on the Firing of Neurons of the Trigeminal Main Sensory Nucleus in the Rat

2010 ◽  
Vol 103 (2) ◽  
pp. 915-923 ◽  
Author(s):  
A. P. Bernier ◽  
I. Arsenault ◽  
J. P. Lund ◽  
A. Kolta
Keyword(s):  
Firing Pattern ◽  
Firing Frequency ◽  
Repetitive Stimulation ◽  
Burst Frequency ◽  
Sensory Afferents ◽  
Sensory Inputs ◽  
Cross Correlation Analysis ◽  
Sensory Nucleus ◽  
Stimulation Of

Mastication can be triggered by repetitive stimulation of the cortex or of sensory inputs, but is patterned by a brain stem central pattern generator (CPG). This CPG may include the dorsal part of the principal trigeminal sensory nucleus (NVsnpr), where neurons burst repetitively when the extracellular concentration of Ca2+ ([Ca2+]e) drops. We examined the effects of repetitive stimulation of sensory afferents of the trigeminal tract on activity of NVsnpr neurons recorded extracellularly in vitro under physiologic [Ca2+]e (1.6 mM). Spontaneously active cells had either a tonic ( n = 145) or a bursting ( n = 46) firing pattern. Afferent stimulation altered burst duration and/or burst frequency in bursting cells and firing frequency in most tonic cells. In 28% of the latter, the firing pattern switched to rhythmic bursting. This effect could be mimicked by local application of N-methyl-d-aspartate and blocked by APV but not DNQX. Detailed analysis showed that rhythm indices (RIs) of 35 tonic neurons that were negative (nonrhythmic) before stimulation became significantly rhythmic (RI ≥ 0.01) after stimulation. Mean and median bursting frequency of these units were 8.32 ± 0.72 (SE) Hz and 6.25 Hz (range, 2.5–17.5 Hz). In seven instances, two units were recorded simultaneously, and cross-correlation analysis showed that firing of six pairs was rhythmic and synchronized after stimulation. Optimal stimulation parameters for eliciting rhythmic bursting consisted in 500-ms trains of pulses delivered at 40–60 Hz. Together, our results show that repetitive stimulation of sensory afferents in vitro can elicit masticatory-like rhythmic bursting in NVsnpr neurons at physiological [Ca2+]e.

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