Current source-density and neuromagnetic analysis of the direct cortical response in rat cortex

The electrophysiological basis of macropotentials produced by the direct cortical response (DCR) to electrical stimulation was studied using a combination of current source-density (CSD) and neuromagnetic analysis. Current source-density analysis indicated the locations of extracellular sources and sinks in the cortical depth giving rise to each temporal component of the DCR complex. Information about intradendritic currents was obtained from extracranial magnetic field measures. These data indicate that the DCR is composed of a sequential activation of pyramidal cells at different cortical depths. The complex begins with depolarization of cells in the upper and middle layers, followed by depolarization of deeper pyramidal cells with apical dendrites extending near the cortical surface. The complex ends with a positive-negative slow wave sequence indicating possible afterhyperpolarization of surface dendrites and hyperpolarization of cell bodies and basilar dendrites in the depth. These data demonstrate a unique way in which electrical and magnetic measures may be combined to provide complementary information about the spatially and temporally organized cellular currents within local neuronal networks.

[1]  Samuel J. Williamson,et al.  Magnetic Fields of the Cerebral Cortex , 1980 .

[2]  M. Oguri,et al.  Vertical spread of neuronal activity within the cat motor cortex investigated with epicortical stimulation and intracellular recording. , 1985, The Japanese journal of physiology.

[3]  F. J. Clark,et al.  Tetrodotoxin analysis of direct cortical responses. , 1968, Electroencephalography and clinical neurophysiology.

[4]  H Hosaka,et al.  Part II: magnetic field produced by a current dipole. , 1976, Journal of electrocardiology.

[5]  H. T. Chang,et al.  Dendritic potential of cortical neurons produced by direct electrical stimulation of the cerebral cortex. , 1951, Journal of neurophysiology.

[6]  J Beatty,et al.  Neuromagnetic evidence of spatially distributed sources underlying epileptiform spikes in the human brain. , 1984, Science.

[7]  E D Adrian,et al.  The spread of activity in the cerebral cortex , 1936, The Journal of physiology.

[8]  K. Ezure,et al.  Lateral spread of neuronal activity within the motor cortex investigated with intracellular responses to distant epicortical stimulation. , 1985, The Japanese journal of physiology.

[9]  M. Clare,et al.  Sites of origin of electric potentials in striate cortex. , 1952, Journal of neurophysiology.

[10]  A. Rosenblueth,et al.  CORTICAL RESPONSES TO ELECTRIC STIMULATION , 1942 .

[11]  William Sutherling,et al.  Intracellular currents of interictal penicillin spikes: Evidence from neuromagnetic mapping , 1986, Brain Research.

[12]  P. E. Stohr,et al.  PATTERNS OF UNIT DISCHARGE ASSOCIATED WITH DIRECT CORTICAL RESPONSE IN MONKEY AND CAT. , 1963, Electroencephalography and clinical neurophysiology.

[13]  EXCITABILITY CYCLE OF THE DIRECT CORTICAL RESPONSE STUDIED WITH MINIMAL STIMULI AND RESPONSE AVERAGING. , 1965, Electroencephalography and clinical neurophysiology.

[14]  Spatial and temporal interaction of direct cortical responses. , 1961, Experimental neurology.

[15]  M. Clare,et al.  [Responses of cortex to direct electrical stimuli applied at different depths]. , 1953, Journal of neurophysiology.

[16]  B. Neil Cuffin,et al.  Magnetic Fields of a Dipole in Special Volume Conductor Shapes , 1977, IEEE Transactions on Biomedical Engineering.

[17]  D R Humphrey,et al.  Re-analysis of the antidromic cortical response. II. On the contribution of cell discharge and PSPs to the evoked potentials. , 1968, Electroencephalography and clinical neurophysiology.

[18]  O D Creutzfeldt,et al.  Relations between EEG phenomena and potentials of single cortical cells. I. Evoked responses after thalamic and erpicortical stimulation. , 1966, Electroencephalography and clinical neurophysiology.

[19]  D. Barth,et al.  Neuromagnetic localization of epileptiform spike activity in the human brain. , 1982, Science.

[20]  S OCHS,et al.  The direct cortical response. , 1956, Journal of neurophysiology.

[21]  D. Purpura,et al.  Nature of dendritic potentials and synaptic mechanisms in cerebral cortex of cat. , 1956, Journal of neurophysiology.

[22]  C. Nicholson,et al.  Theory of current source-density analysis and determination of conductivity tensor for anuran cerebellum. , 1975, Journal of neurophysiology.

[23]  Sidney Goldring,et al.  Direct response of isolated cerebral cortex of cat. , 1961, Journal of neurophysiology.

[24]  S. Ochs,et al.  LAMINAR STIMULATION FOR DIRECT CORTICAL RESPONSES FROM INTACT AND CHRONICALLY ISOLATED CORTEX. , 1964, Electroencephalography and clinical neurophysiology.

[25]  M. Clare,et al.  Properties of dendrites; apical dendrites of the cat cortex. , 1955, Electroencephalography and clinical neurophysiology.

[26]  S. Goldring,et al.  INTRACELLULAR POTENTIALS ASSOCIATED WITH DIRECT CORTICAL RESPONSE AND SEIZURE DISCHARGE IN CAT. , 1964, Electroencephalography and clinical neurophysiology.

[27]  J Beatty,et al.  Magnetic localization of a dipolar current source implanted in a sphere and a human cranium. , 1986, Electroencephalography and clinical neurophysiology.

[28]  C. Li,et al.  Cortical intracellular synaptic potentials and direct cortical stimulation. , 1962, Journal of cellular and comparative physiology.

[29]  J Beatty,et al.  Fast and slow magnetic phenomena in focal epileptic seizures. , 1984, Science.

[30]  U. Mitzdorf.  Current source-density method and application in cat cerebral cortex: investigation of evoked potentials and EEG phenomena. , 1985, Physiological reviews.