Effects of changes in carbon dioxide tension in abnormally prolonged contingent negative variation (CNV)
Dubrovsky, B.; Garcia-Rill, E.; Simkus, R.; Dongier, M.
Biological Psychiatry 11(5): 535-541
1976
ISSN/ISBN: 0006-3223 PMID: 971450 Document Number: 99607
The effects of changes in pCO2 [CO2 tension] in the development and resolution of normal [return to base line within 2 s after S2 (2nd stimulus)] and abnormal [return to base line in more than 2 s after S2] CNV were studied in 12 psychiatric patients. Decreased pCO2 produced by hyperventilation induced a significant reduction in the duration of the postimperative negative variation (PINV) without significantly affecting the amplitude of the CNV. Increased pCO2, by inhalation of 5% CO2, on the contrary, produced prolongation of the PINV in 2 subjects. Control subjects with normal CNV did not show significant changes in the amplitude or in the duration of the CNV wave when pCO2 was altered. The results were discussed in terms of the possible independence and higher sensitivity to metabolic changes of the PINV brain generators compared with the generators of the CNV wave per se.