TY - JOUR
T1 - Acetylcholine epilepsy
T2 - Relationship of surface concentration, chronicity of denervation, and focus size
AU - Ferguson, John H.
AU - Cornblath, David R.
N1 - Funding Information:
The capacity for epileptic activity is the property of a group of nervous elements. Although individual elements may reveal abnormal characteristics during seizure, it is generally agreed that an aggregate is required for the phenomenon (2). Whether the basic abnormality involves the group as a whole or only parts thereof has not been determined. It is clear, however, that groups as a whole differ widely in seizure threshold. For instance, 1 Read in part before the Society for Neuroscience 3rd annual meeting in San Diego, CA, November, 1973. Supported in part by PHS-NIH Research Grant NO. 1 ROI NS09877-01 and by PHS-NIH Training Grant NO. 2 TO1 NS05087-17 from the National Institute of Neurological Diseases and Stroke. Reprint requests to Division of Neurology, University Hospitals, Cleveland, OH 44106 (Dr. Ferguson).
Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 1975/2
Y1 - 1975/2
N2 - Experiments were performed on intact and chronically undercut cat suprasylvian gyrus attempting to determine a critical minimum size of cortical aggregate for acetylcholine (Ach) induced epileptiform activity. Cortical seizure foci of different sizes, 4 × 4 mm, 2 × 2 mm, and 1 × 1 mm were made with filter papers wetted to contain equal fluid volumes with equimolar amounts of Ach per unit area for each experiment. Concentrations of Ach varied from 0.5% (3.4 nmoles/mm2) to 4% (28 nmoles/mm2). The following results were obtained: The probability of seizure increased with increasing focus size and with increasing amount of Ach per mm2 of filter paper. Seizure occurred reliably with small (1 × 1 mm) foci in intact animals with 28 nmoles of Ach, whereas only 6.8 nmoles was required in chronically undercut preparations of 31 days or more. Average time to seizure onset was 8.75 min and was not statistically different for different size foci. No minimum cortical aggregate size necessary for Ach induced seizure could be established with this method. The size may vary under differing stimulus conditions but the results suggest that a volume with linear dimensions of 1 mm or less would be large enough.
AB - Experiments were performed on intact and chronically undercut cat suprasylvian gyrus attempting to determine a critical minimum size of cortical aggregate for acetylcholine (Ach) induced epileptiform activity. Cortical seizure foci of different sizes, 4 × 4 mm, 2 × 2 mm, and 1 × 1 mm were made with filter papers wetted to contain equal fluid volumes with equimolar amounts of Ach per unit area for each experiment. Concentrations of Ach varied from 0.5% (3.4 nmoles/mm2) to 4% (28 nmoles/mm2). The following results were obtained: The probability of seizure increased with increasing focus size and with increasing amount of Ach per mm2 of filter paper. Seizure occurred reliably with small (1 × 1 mm) foci in intact animals with 28 nmoles of Ach, whereas only 6.8 nmoles was required in chronically undercut preparations of 31 days or more. Average time to seizure onset was 8.75 min and was not statistically different for different size foci. No minimum cortical aggregate size necessary for Ach induced seizure could be established with this method. The size may vary under differing stimulus conditions but the results suggest that a volume with linear dimensions of 1 mm or less would be large enough.
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U2 - 10.1016/0014-4886(75)90137-5
DO - 10.1016/0014-4886(75)90137-5
M3 - Article
C2 - 1116505
AN - SCOPUS:0016437715
SN - 0014-4886
VL - 46
SP - 302
EP - 314
JO - Experimental Neurology
JF - Experimental Neurology
IS - 2
ER -