Effect of spontaneous activity on afferent response in the MES auditory cortex of the dog

Treating the spontaneous electrical activity (SEA) and the evoked potential due to a p pulse at the MES auditory cortex as random variables at 3-msec. epochs, an increase in standard deviation during the evoked potential was found suggesting the occurrence of two statistical processes. By suitable application of cocaine hydrochloride locally to the cortex, it was possible to suppress the standard deviation of SEA and obtain a potential with no or little variance. This potential was defined as the ‘afferent response’ representing the activity due to volleys from the ear. It was concluded that the locally arising SEA has connections to the nerve elements causing the afferent response, thus producing the variance of the evoked potential. The SEA, therefore, is an information destroying process, since it reduces the detectability of response from stimulation of the ear.

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Components of the evoked potential in the MES auditory cortex

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1960.199.3.529 ◽

1960 ◽

Vol 199 (3) ◽

pp. 529-534 ◽

Cited By ~ 2

Author(s):

Archie R. Tunturi

Keyword(s):

Standard Deviation ◽

Auditory Cortex ◽

Electrical Activity ◽

Evoked Potential ◽

Random Variable ◽

Positive Component ◽

Negative Component ◽

Spontaneous Electrical Activity ◽

Covariance Term ◽

The Mean

The electrical activity during the potential evoked by a p pulse was analyzed statistically by considering amplitude at each 3-msec. epoch a random variable. The rise in standard deviation during the evoked potential was abolished a) by local cocaine on the cortex, b) by a preceding evoked potential and c) by ischemia. The residual mean positive component, with zero standard deviation, was subtracted from the mean of the evoked potential. This yielded a positive-negative component, with which the spontaneous electrical activity is believed to interact. The evoked potential is thus described as the sum of the three random variables: a) spontaneous electrical activity, b) positive component, and c) positive-negative component, with a covariance term involving the spontaneous electrical activity and the positive-negative component.

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Statistics of spontaneous electrical activity of supra- and ectosylvian gyri of the dog

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1963.204.1.51 ◽

1963 ◽

Vol 204 (1) ◽

pp. 51-59

Author(s):

Archie R. Tunturi

Keyword(s):

Standard Deviation ◽

Electrical Activity ◽

Negative Correlation ◽

Evoked Potential ◽

Correlation Coefficients ◽

Moderate Correlation ◽

Spontaneous Electrical Activity ◽

Suprasylvian Gyrus ◽

The Mean ◽

Standard Deviations

The standard deviations of the spontaneous electrical activity (SEA) of the suprasylvian gyrus (SSG) ranged between 57–131 µv and for the middle ectosylvian (MES) gyrus, 88–175 µv. Correlation coefficients, r, served to distinguish three regions of the SSG. The rostral showed low correlation with the middle, high correlation with the caudal, and low to negative correlation with the MES. The middle showed moderate correlation with the MES, and the caudal showed zero to negative correlation with the MES. Within the SSG, correlation was low and in the MES high, for spacings of 2 mm. Cocaine applied to both areas sharpened the boundaries at the sulci, reduced standard deviations, did not affect the correlation between the caudal SSG and the MES area, and increased r between all locations in the MES but not in the SSG. Cocaine on the SSG had no effect on the mean and standard deviation of the evoked potential in the MES, but decreased r of the SEA significantly.

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Cerebral-evoked potential responses following direct vagal and esophageal electrical stimulation in humans

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1993.264.3.g486 ◽

1993 ◽

Vol 264 (3) ◽

pp. G486-G491 ◽

Cited By ~ 10

Author(s):

G. Tougas ◽

P. Hudoba ◽

D. Fitzpatrick ◽

R. H. Hunt ◽

A. R. Upton

Keyword(s):

Electrical Stimulation ◽

Evoked Potential ◽

Vagal Stimulation ◽

Direct Electrical Stimulation ◽

Sensory Pathways ◽

Afferent Fibers ◽

Health And Disease ◽

Esophageal Sphincter ◽

Afferent Response ◽

Stimulation Of

Cerebral evoked responses following direct electrical stimulation of the vagus and esophagus were compared in 8 epileptic subjects and with those recorded after esophageal stimulation in 12 healthy nonepileptic controls. Direct vagal stimulation was performed using a left cervical vagal pacemaker, which is used in the treatment of epilepsy. Esophageal stimulation was obtained with the use of an esophageal assembly incorporating two electrodes positioned 5 and 20 cm orad to the lower esophageal sphincter. Evoked potential responses were recorded with the use of 20 scalp electrodes. The evoked potential responses consisted of three distinct negative peaks and were similar with the use of either vagal or esophageal stimulation. The measured conduction velocity of the afferent response was 7.5 m/s in epileptic subjects and 10 m/s in healthy controls, suggesting that afferent conduction is through A delta-fibers rather than slower C afferent fibers. We conclude that the cortical-evoked potential responses following esophageal electrical stimulation are comparable to direct electrical stimulation of the vagus nerve and involve mostly A delta-fibers. This approach provides a method for the assessment of vagal afferent gastrointestinal sensory pathways in health and disease.

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Statistical properties of near threshold responses to brief sounds in the MES auditory cortex of the anesthetized dog

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1959.196.6.1168 ◽

1959 ◽

Vol 196 (6) ◽

pp. 1168-1174

Author(s):

Archie R. Tunturi

Keyword(s):

Standard Deviation ◽

Auditory Cortex ◽

Evoked Potential ◽

Zero Crossing ◽

Essentially Normal ◽

Average Potential ◽

Posterior Direction ◽

The Mean ◽

Anterior Posterior ◽

Near Threshold

Evoked responses to near threshold p pulses recorded with a 50-channel cathode ray oscilloscope from the MES auditory cortex were analyzed statistically. Observations were taken at 3-msec. epochs for approximately 180 msec. Density functions of the evoked potential at these epochs were essentially normal. The average potential from a single electrode consisted of an initial positive followed by a negative component. The correlation coefficient between the positive and negative components was zero suggesting independence. Standard deviation increased during the positive component of a response decreasing to the zero crossing or was followed by a secondary component. Spatially, in the anterior-posterior direction, the average potentials decremented to approximately zero in 2–4 mm. The decrement was less prominent dorso-ventrally. Spatially, the standard deviation showed the same pattern as the mean.

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The functional anatomy of middle-latency auditory evoked potentials: thalamocortical connections

Journal of Neurophysiology ◽

10.1152/jn.1992.68.2.425 ◽

1992 ◽

Vol 68 (2) ◽

pp. 425-431 ◽

Cited By ~ 41

Author(s):

S. Di ◽

D. S. Barth

Keyword(s):

Electrical Stimulation ◽

Auditory Cortex ◽

Evoked Potentials ◽

Linear Combination ◽

Evoked Potential ◽

Medial Geniculate Body ◽

Cortex Area ◽

Medial Geniculate ◽

Potential Complex ◽

Stimulation Of

1. An 8 x 8-channel microelectrode array was used to map epicortical field potentials from a 4.375 x 4.375-mm2 area in the right parietotemporal neocortex of four rats. Potentials were evoked with bilaterally presented click stimuli and with electrical stimulation of the ventral and dorsal divisions of the medial geniculate body. 2. Epicortical responses to click stimuli replicated earlier findings. The responses consisted of a positive-negative biphasic waveform (P1a and N1) in the region of primary auditory cortex (area 41) and a positive monophasic waveform (P1b) in the region of secondary auditory cortex (area 36). Two potential patterns, one at the latency of the N1 and the other at the latency of the P1b, were used to represent activation of cells within areas 41 and 36. A linear combination of these patterns was sufficient to explain from 90 to 94% of the variance of the evoked potential complex at all latencies. 3. In the same animals, epicortical responses to electrical stimulation of the ventral and dorsal divisions of the medial geniculate body were also localized to areas 41 and 36, respectively. A linear combination of potential patterns from these separate stimulation conditions was sufficient to explain from 80 to 93% of the variance of the original click-evoked potential complex at all latencies. 4. These data provide functional evidence for anatomically defined topographical thalamocortical projections to primary and secondary auditory cortex. They suggest that short-latency cortical evoked potentials (10-60 ms poststimulus) are dominated by parallel thalamocortical activation of areas 41 and 36.

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Statistical properties of spontaneous electrical activity in the MES auditory cortex of the anesthetized dog

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1959.196.6.1175 ◽

1959 ◽

Vol 196 (6) ◽

pp. 1175-1180 ◽

Cited By ~ 3

Author(s):

Archie R. Tunturi

Keyword(s):

Standard Deviation ◽

Electrical Activity ◽

Correlation Coefficients ◽

Positive Component ◽

Chi Square ◽

True Response ◽

Spontaneous Electrical Activity ◽

Posterior Direction ◽

The Mean ◽

Anterior Posterior

The spontaneous electrical activity was sampled at 2-second intervals from 50 electrodes on the MES area. Chi-square tests indicated normality for the amplitude values of potential obtained at each electrode. The range for standard deviations was 43–113 µv but averaged between 77 and 85 for three animals. Correlation coefficients greater than 0.7 were obtained between electrodes 2 mm apart in the anterior-posterior direction with a decrement to 0.4 at a separation of 4 mm. Dorso-ventrally, correlations greater than 0.7 were obtained between electrodes 4–6 mm apart, suggesting a strip-like character. Low values of correlation were obtained between an electrode in the MES area and an electrode on the AES or PES area. Assuming independence of the true response and spontaneous electrical activity the mean curve and standard deviation curve of the true response were computed. The standard deviation curve of the true response increased during the positive component gradually decreasing toward the end of the negative component.

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Increased Spontaneous Electrical Activity at a Latent Myofascial Trigger Point After Nociceptive Stimulation of Another Latent Trigger Point

Clinical Journal of Pain ◽

10.1097/ajp.0b013e3181bad736 ◽

2010 ◽

Vol 26 (2) ◽

pp. 138-143 ◽

Cited By ~ 26

Author(s):

Josué Fernández-Carnero ◽

Hong-You Ge ◽

Yoshiyuki Kimura ◽

César Fernández-de-las-Peñas ◽

Lars Arendt-Nielsen

Keyword(s):

Electrical Activity ◽

Trigger Point ◽

Myofascial Trigger Point ◽

Nociceptive Stimulation ◽

Spontaneous Electrical Activity ◽

Stimulation Of

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Measurement of spontaneous neuronal membrane activity by time lapse confocal microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100141238 ◽

1995 ◽

Vol 53 ◽

pp. 972-973

Author(s):

R H. Selinfreund ◽

A. H. Cornell-Bell

Keyword(s):

Membrane Potential ◽

Confocal Microscopy ◽

Patch Clamp ◽

Electrical Activity ◽

Time Lapse ◽

Neuronal Firing ◽

Neuronal Membrane ◽

Pituitary Cells ◽

Patch Clamp Recording ◽

Spontaneous Electrical Activity

Cellular electrophysiological properties are normally monitored by standard patch clamp techniques . The combination of membrane potential dyes with time-lapse laser confocal microscopy provides a more direct, least destructive rapid method for monitoring changes in neuronal electrical activity. Using membrane potential dyes we found that spontaneous action potential firing can be detected using time-lapse confocal microscopy. Initially, patch clamp recording techniques were used to verify spontaneous electrical activity in GH4\C1 pituitary cells. It was found that serum depleted cells had reduced spontaneous electrical activity. Brief exposure to the serum derived growth factor, IGF-1, reconstituted electrical activity. We have examined the possibility of developing a rapid fluorescent assay to measure neuronal activity using membrane potential dyes. This neuronal regeneration assay has been adapted to run on a confocal microscope. Quantitative fluorescence is then used to measure a compounds ability to regenerate neuronal firing.The membrane potential dye di-8-ANEPPS was selected for these experiments. Di-8- ANEPPS is internalized slowly, has a high signal to noise ratio (40:1), has a linear fluorescent response to change in voltage.

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Electrical activity of the ventromedial nucleus of the hypothalamus

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1959.197.4.829 ◽

1959 ◽

Vol 197 (4) ◽

pp. 829-834 ◽

Cited By ~ 14

Author(s):

Dana C. Brooks

Keyword(s):

Electrical Activity ◽

Slow Waves ◽

Ventromedial Nucleus ◽

Spontaneous Electrical Activity ◽

Pentobarbital Anesthesia

The spontaneous electrical activity of the ventromedial nucleus was studied in the cat under pentobarbital anesthesia and in the unanesthetized, unrestrained state. Under light pentobarbital anesthesia the activity of the nucleus is characterized by a predominant 9–15 cps, 50–100 µv component which is uniform from second to second. With small additional doses of anesthesia there is a selective depression of this activity; with recovery from light anesthesia this activity is gradually replaced by irregular, large, slow waves characteristic of sleep. When the unanesthetized animal is aroused 20–35 cps activity having an amplitude of 40 µv or more appears in the nucleus. While the pattern of activity during sleep resembles that seen elsewhere in the hypothalamus, the activity seen during barbiturate anesthesia and during arousal is confined to the nucleus and not seen in other parts of the diencephalon.

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