Projections of phrenic afferences to the cat cerebellar cortex.

Evoked phrenic potentials were recorded on the cerebellar cortex of anesthetized adult cats after electrical stimulation of both cervical branches (C5 and C6) of the right phrenic nerve. In this case phrenic stimulation evoked a surface positive response with a mean amplitude (+/- S.D.) of 13.4 +/- 5.2 microV. The mean latency and the mean duration of this phase were, respectively, 9.5 +/- 1.2 ms and 19.4 +/- 2.1 ms. This response was found only in the ipsilateral intermediate cortex and in the ipsilateral and, to a less extent, in the contralateral vermis of the posterior part of the anterior lobe (Larsell's lobule V); these areas corresponding to the forelimb projection zones. The phrenic afferences projecting to the cerebellar cortex were essentially conducted in the contralateral ventro-lateral spinal tracts.