Projection to cerebral cortex of Group I muscle afferents from the cat's hind limb

Abstract

SUMMARY1. Muscle afferent projections from the contralateral hind limb to the postsigmoid gyrus of the cerebral cortex were investigated in cats anaesthetized with chloralose. The evoked potentials were recorded from the cortical surface or from deeper layers by penetrating micro-electrodes. Graded electrical stimulation of the nerves was used.2. Group Ia as well as Ib muscle afferents from the contralateral quadriceps, posterior biceps-semitendinosus, gastrocnemius-soleus and deep peroneal muscles projected to two different loci in the postsigmoid gyrus. One of these was located on the dorsal surface of the hemisphere 4-5 mm lateral to the mid line and 1-3 mm posterior to the cruciate sulcus, thus rostro-miedial to the postcruciate dimple. The other was located on the medial surface of the hemisphere adjacent to the cruciate sulcus. There was no overlap between the two loci.3. There was no significant difference in thresholds or latencies of the Group I responses in the two loci. The latency was short and similar to that of the potential evoked by the cutaneous afferents in the somatosensory primary projection areas.4. The Group lb path was largely independent of the Ia path, because a maximal Group I volley evoked a response, when the Ia path was made refractory by simultaneous stimulation with a maximal I a volley at 20 per second.5. The cortical potentials evoked by the Group I muscle afferents from the contralateral hind limb did not change after transection of the dorsal columns at C 1-C 3 levels but disappeared after a superficial section in the dorsolateral fascicle at C 1 level. The responses were not affected by cerebellectomy. It was concluided that the path travelled with the dorsal spinocerebellar tract or utilized brain stem collaterals of this tract.6. Group II muscle afferents evoked a response near the border of the S. LANDGREN AND H. SILFVENI US Group I loci, but not in the positions where the Group I responses were maximal in amplitude.7. The receptor origin of the stimulated Group I afferents, the location of the medullary relay in the Group I path and the destination of the efferent outflow from the Group I loci were discussed.

Vagal Input to Lateral Area 3a in Cat Cortex

“…Activation of group I inputs, for example, evokes in area 3a a so-called thalamocortical primary response with an initially positive surface wave that reverses polarity in deep layers (Landgren and Silfvenius 1969;Odkvist et al 1975). Iwata et al (1985) described a masseteric-nerve-evoked potential, which reversed to a deep negative component at a depth of 1.5-2.5 mm, in the rostral part of cat area 3a, consistent with our observations.…”

Maintenance of constant arm position or force: reflex and volitional components in man.

“…There is both electrophysiological (Oscarrson & Rosen, 1963;Landgren & Silfvenius, 1969; McIntyre, Proske & Rawson, 1984) and psychophysical (Goodwin, McCloskey & J. G. COLEBATCH AND D. I. McCLOSKEY Matthews, 1972;McCloskey, Ebeling & Goodwin, 1974;Roland & LadegaardPederson, 1977) evidence to support a role for the primary spindle ending and the Golgi tendon organ in kinaesthetic sensations. Our results suggest that this proprioceptive information can be utilized in the volitional control ofthe limbs.…”

Projection from low‐threshold muscle afferents of hand and forearm to area 3a of baboon's cortex

“…In the cat, the cortical receiving area for the spindle input, as deter-420 AREA 3a OF BABOON'S CORTEX mined electrophysiologically (Oscarsson & Rosen, 1963, 1966Landgren & Silfvenius, 1969), does not correspond to area 4, but to area 3a as determined cytoarchitectonically (Hassler & Muhs-Clement, 1964). In the monkey area 3 a lies in the depth of the Rolandic fissure (Roberts & Akert, 1963;Powell & Mountoastle, 1959a).…”