Direct electrical stimulation of human cortex evokes high gamma activity that predicts conscious somatosensory perception

MacDonald, Kurt D., Eva Fifkova, Michael S. Jones, and Daniel S. Barth. Focal stimulation of the thalamic reticular nucleus induces focal gamma waves in cortex. J. Neurophysiol. 79: 474–477, 1998. Electrical stimulation of the thalamic reticular nucleus (TRN; 0.5-s trains of 500-Hz 0.5-ms pulses at 5–10 μA) evokes focal oscillations of cortical electrical potentials in the gamma frequency band (∼35–55 Hz). These evoked oscillations are specific to either the somatosensory or auditory cortex and to subregions of the cortical receptotopic map, depending on what part of the TRN is stimulated. Focal stimulation of the internal capsule, however, evokes focal slow potentials, without gamma activity. Our results suggest that the TRN's role extends beyond that of general cortical arousal to include specific modality and submodality activation of the forebrain.

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458. Extracellular levels of GABA and glutamate increase in response to direct electrical stimulation of the hippocampus in humans: an in vivo microdialysis study

Biological Psychiatry ◽

10.1016/s0006-3223(00)00728-9 ◽

2000 ◽

Vol 47 (8) ◽

pp. S140

Author(s):

W.M. Abi-Saab ◽

D.D. Spencer ◽

V. Srihari ◽

J.L. Thompson ◽

R.H. Roth ◽

...

Keyword(s):

Electrical Stimulation ◽

In Vivo Microdialysis ◽

Direct Electrical Stimulation ◽

Microdialysis Study ◽

Stimulation Of

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Backward and forward masking for direct electrical stimulation of the VIIIth nerve in two profoundly deaf subjects

The Journal of the Acoustical Society of America ◽

10.1121/1.2024955 ◽

1987 ◽

Vol 82 (S1) ◽

pp. S72-S72 ◽

Cited By ~ 3

Author(s):

L. J. Dent ◽

B. S. Townshend

Keyword(s):

Electrical Stimulation ◽

Forward Masking ◽

Direct Electrical Stimulation ◽

Viiith Nerve ◽

Stimulation Of

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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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