ASTROCYTES AS RAPID SENSORS OF PERIPHERAL AXOTOMY IN THE FACIAL NUCLEUS OF RATS

FACIAL nerve transection leads to functional and structural reactions in lesioned motor neurones and surrounding glial cells. Data from this stud provide evidence that the most rapid reaction described so far c onsists of an increase in immunoreactivity of connexin-43 (cx-43), the predominant gap junction protein in astrocytes. The ipsilateral facia l nucleus is selectively marked as early as 0.75 to 1.5 hours after ax otomy, while the unlesioned side as well as the unoperated controls re main faintly stained. Thus, enhanced coupling capacity of astrocytes b y gap junctions appears to be a sensitive indicator of modified neuron al-glial interaction in the CNS.