These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Does contralateral circling involve action of drugs on hyposensitive striatal dopamine receptors in the hemisphere contralateral to denervation?
    Author: Costall B, Kelly ME, Naylor RJ.
    Journal: Neuropharmacology; 1983 Mar; 22(3):295-302. PubMed ID: 6133233.
    Abstract:
    Rats receiving unilateral intrastriatal injections of 6-hydroxydopamine (6-OHDA) (3 x 16 micrograms, in the presence of tranylcypromine and desmethylimipramine (DMI), resulting in 84% dopamine depletion) exhibited contralateral asymmetry and circling behaviour on peripheral challenge with apomorphine or on unilateral intrastriatal injection of dopamine (into the denervated striatum) (resulting in a stable response after 8 days). The denervated striatum was markedly more sensitive to the effects of dopamine than the normal striatum, although dopamine failed to elicit a response from an intact striatum opposite to a denervation by 6-OHDA. Following unilateral striatal electrolytic lesions (resulting in a stable response after 6-8 days) the rats exhibited ipsilateral asymmetry and circling after the apomorphine challenge. Again, the striata opposite to the lesion failed to mediate a response to dopamine. The contralateral responses to apomorphine observed in animals lesioned with 6-OHDA were not enhanced when an electrolytic lesion was subsequently placed in the intact striatum, nor were the ipsilateral responses of lesioned rats to apomorphine enhanced when 6-OHDA was subsequently injected into the opposite striatum. All asymmetric and circling responses were sensitive to neuroleptics. Thus, it is concluded that a unilateral striatal lesion produced by 6-OHDA or electrolytic lesion can cause reduced functional dopaminergic activity in the opposing striatum. This dopaminergic hyposensitivity would facilitate a contralateral response initiated by hypersensitive mechanisms in the denervated striatum.
    [Abstract] [Full Text] [Related] [New Search]