Differentiation of dopaminergic neurones in situ, in vitro, and in the transplant

Four stages were distinguished in differentiation of the hypothalamic dopaminergic (DA) neurones: a) origin of the neurone, b) expression of enzymes and dopamine specific synthesis and of the dopamine transmembrane transportation mechanisms, c) development of permanent and transient efferent connections, d) forming of afferent innervation and synaptogenesis. The differentiating DA neurones revealed sexual dimorphism in the neurone origin dynamics and in expression of the enzyme synthesis. The maternal and placenta factors did not affect the differentiation of the DA neurones. The period from the 6th to 10th foetal week was found to be optimal for transplantation of the neurones to the striatum of parkinsonian patients. Grafted DA neurones seem to get involved in regulation of the target neurones in the striatum.