Thalamic rhythms in cat during quiet wakefulness and immobility.

In this study we tried to get some more information on the cortical 'mu' rhythms in normal cat and their thalamic pacemaker. Mu (14 c/sec) activity develops when the animal is motionless, in a state of 'quiet waking.' It is distinct from other sensorimotor rhythms, with distinct cortical distributions, distinct frequencies and appearing under different behavioural and environmental conditions. The cortical mu focus was shown to be centred within a restricted part of area SI, in the forepaw and wrist projection field. The related thalamic focus was localized in a small zone of the VP nucleus that also corresponded to the hand and wrist projection area. A coherence study confirmed the close relationship between the two foci, thalamic and cortical. After unilateral electrolytic destruction of the thalamic area, a small mu activity persisted, on the ipsilateral cortex, originating from the opposite side. After bilateral lesion of the VP foci, no mu activity could ever be recorded on either side, while the other sensorimotor rhythms were left intact.

[1]  V. Mountcastle.  Modality and topographic properties of single neurons of cat's somatic sensory cortex. , 1957, Journal of neurophysiology.

[2]  J. Bouyer,et al.  Fast fronto-parietal rhythms during combined focused attentive behaviour and immobility in cat: cortical and thalamic localizations. , 1981, Electroencephalography and clinical neurophysiology.

[3]  A. Rougeul,et al.  Rythmes electrocorticaux caracterisques de l'installation du sommeil naturel chez le chat. leurs rapports avec le comportement moteur , 1974 .

[4]  David P. Friedman,et al.  Focal projection of electrophysiologically defined groupings of thalamic cells on the monkey somatic sensory cortex , 1980, Brain Research.

[5]  V. Mountcastle,et al.  An organizing principle for cerebral function : the unit module and the distributed system , 1978 .

[6]  V. Mountcastle,et al.  Posterior parietal association cortex of the monkey: command functions for operations within extrapersonal space. , 1975, Journal of neurophysiology.

[7]  J. Corvisier,et al.  Activite rythmique du cortex somesthesique primaire en relation avec l'immobilite chez le chat libre eveille , 1972 .

[8]  H. A. Gastaut,et al.  Étude topographique des réactions électroencéphalographiques conditionnées chez l'homme: (Essai d'interprétation neurophysiologique) , 1957 .

[9]  J. Bouyer,et al.  From attentiveness to sleep. A topographical analysis of localized "synchronized" activities on the cortex of normal cat and monkey. , 1975, Acta Neurobiologiae Experimentalis.

[10]  M B Sterman,et al.  Cortical-subcortical EEG correlates of suppressed motor behavior during sleep and waking in the cat. , 1972, Electroencephalography and clinical neurophysiology.

[11]  S P Wise,et al.  Cytoarchitecture and thalamic connectivity of third somatosensory area of cat cerebral cortex. , 1978, Journal of neurophysiology.

[12]  G. King.  Brain stem blood vessels and the organization of the lateral reticular formation in the medulla oblongata of the cat , 1980, Brain Research.

[13]  M B Sterman,et al.  EEG correlates of sleep: evidence for separate forebrain substrates. , 1967, Brain research.

[14]  M. Sterman,et al.  Comparison of EEG correlates of reinforcement, internal inhibition and sleep. , 1967, Electroencephalography and clinical neurophysiology.

[15]  S. Andersson,et al.  Rhythmic activity in the thalamus of the unanaesthetized decorticate cat. , 1971, Electroencephalography and clinical neurophysiology.

[16]  H. Jasper,et al.  A stereotaxic atlas of the diencephalon of the cat , 1960 .