ZINC TRANSPORT FROM THE STRIATUM AND SUBSTANTIA-NIGRA

Zn-65 was unilaterally injected into the striatum or substantia nigra of rats to see the transport of intracerebral zinc (Zn). In the case o f intrastriatal injection, Zn-65 was densely distributed in the ipsila teral medial forebrain bundle (MFB) and the substantia nigra. On unila teral colchicine injection into the MFB, Zn-65 distribution in the ips ilateral substantia nigra decreased significantly compared to that of the contralateral one after Zn-65 injection into the bilateral striata . These results suggest the presence of axonal transport of Zn-65 take n up by striatonigral gamma-aminobutyric acid (GABA)-ergic and/or nigr ostriatal dopaminergic neurons. On the other hand, in the case of intr anigral injection,Zn- 65 was distributed in the ipsilateral MFB, stria tum, globus pallidus, pontine reticular nuclei, and pontine nuclei. Zn -65 distribution in the pens 1 day after intranigral injection was ver y similar to that 6 days after intrastriatal injection, suggesting tha t, in the case of intrastriatal injection of Zn-65, nigral Zn-65, whic h was transported anterogradely and/or retrogradely from the striatum, was transported to the postsynaptic neurons through the synapse and t hen transported to the pens. (C) 1998 Elsevier Science Inc.