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: Involvement of dopamine in circling responses to muscimol depends on intranigral site of injection.
    Author: Kilpatrick IC, Starr MS.
    Journal: Eur J Pharmacol; 1981 Feb 19; 69(4):407-19. PubMed ID: 6265225.
    Abstract:
    The intensity, direction and dopamine dependence of circling behaviour were determined following stereotaxic injections of 40 ng muscimol (in 0.2 microliter over 3 min) into different regions of the rat's substantia nigra (SN). Weak, haloperidol-sensitive ipsilateral postural or locomotor asymmetries were invariably obtained from the rostral SN zona compacta (SNC), whilst robust contraversive rotational behaviour was always initiated from the SN zona reticulata (SNR) and caudal SNC. This was most rapid from the central SNR and was markedly attenuated by i.p. pretreatment with haloperidol (0.1 mg/kg) or pimozide (0.25 mg/kg), or by week-old 6-OHDA lesions of the nigrostriatal dopamine (DA) tract. Turning was significantly weaker from the lateral and ventral areas of the SNR, where it was not susceptible to DAergic blockade. Lower circling rates were also obtained if the SNR injections were made rapidly (in 30 sec), in a large volume (0.5 microliter) or at a supramaximal dose level (400 ng), possibly due to increased spread of the drug to remote neurones having an opposite effect on directional behaviour, or to exaggerated stereotypy. The variable action of muscimol at multiple sites in the SN is suggested to account for the earlier conflicting data in the literature.
    [Abstract] [Full Text] [Related] [New Search]