Changes in function and ultrastructure of striatal dopaminergic terminals that regenerate following partial lesions of the SNpc.

摘要: Following partial substantia nigra lesions, remaining dopaminergic neurones sprout, returning terminal density in the dorsal striatum to normal by 16 weeks. This suggests regeneration and maintenance of is regulated release appropriate levels dopamine. study examined structure function these reinnervated terminals, defining characteristics dopamine uptake release, affinity transporter (DAT) ultrastructural morphology terminals striatum. Finally, rotational behaviour animals response amphetamine was 4 weeks after pars compacta (SNpc) lesions. Dopamine transport markedly reduced lesioning along with DAT. Rate peak concentration, measured electrochemically, similar lesioned control animals, while clearance prolonged lesioning. Ultrastructurally, were morphologically distinct, having increased bouton size, vesicle number mitochondria, more proximal contacts on post-synaptic cells. After weeks, tendency rotate proportional lesion size. By returned near where lesions less than 70%, although some demonstrated unusual patterns at beginning end effect. Together, changes indicate that sprouted are well compensated for but mechanisms functionally impaired. We discuss results terms implications dyskinesia other behavioural states.