Activation of nigral M1 and M2 muscarinic receptors produces opposing effects on striatal 3,4-dihydroxyphenylacetic acid measured by in vivo voltammetry.
3,4-dihydroxyphenylacetic acid (DOPAC) was measured by differential pulse voltammetry in the neostriatum of anesthetized rats. DL-Muscarine (2.9 nmol) applied into the substantia nigra pars compacta, increased DOPAC concentration in the ipsilateral neostriatum. This effect was blocked by pirenzepine (2.8 nmol), and potentiated by AF-DX 116 (2.8 nmol). These results indicate the existence of two types of muscarinic receptors on dopaminergic neurons, whose activation produces opposing effects on dopamine metabolism in neostriatum.
Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional de México, D.F., Mexico.
J L
JL
Góngora-Alfaro
S
S
Hernández-López
D
D
Martínez-Fong
J L
JL
Brassart
J
J
Aceves
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism*; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D004563:Electrochemistry / Q000379:methods; D007839:Functional Laterality; D008297:Male; D009116:Muscarine / Q000008:administration & dosage / Q000494:pharmacology*; D010276:Parasympatholytics / Q000494:pharmacology; D010890:Pirenzepine / Q000031:analogs & derivatives / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011976:Receptors, Muscarinic / Q000187:drug effects / Q000502:physiology*; D013238:Stereotaxic Techniques; D013378:Substantia Nigra / Q000187:drug effects / Q000502:physiology*
D010276:Parasympatholytics; D011976:Receptors, Muscarinic; D015102:3,4-Dihydroxyphenylacetic Acid; D010890:Pirenzepine; D009116:Muscarine; C048593:otenzepad