Does treatment with haloperidol for 3 weeks produce depolarization block in midbrain dopamine neurons of unanaesthetized rats?
Treatment of rats with haloperidol, 0.5 mg/kg SC daily for 3 weeks, did not increase the concentration of dopamine in the dopamine-rich nuclei of the forebrain apart from a small effect in the olfactory tubercle. Cessation of the nerve impulse flow in the ascending dopamine neurons induced by gamma-butyrolactone caused an approximately twofold increase in the dopamine levels of both haloperidol-treated and control rats. The results are hard to reconcile with the notion of haloperidol-induced depolarization block, i.e., cessation of impulse flow in the majority of midbrain dopamine neurons of unanaesthetized rats.
Andén
N E
NE
Department of Pharmacology, Karolinska Institute, Stockholm, Sweden.
Grenhoff
J
J
Svensson
T H
TH
D015107:4-Butyrolactone / Q000494:pharmacology; D000758:Anesthesia; D000818:Animals; D006220:Haloperidol / Q000494:pharmacology*; D008297:Male; D008636:Mesencephalon / Q000187:drug effects / Q000378:metabolism*; D009467:Neuromuscular Depolarizing Agents; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D009467:Neuromuscular Depolarizing Agents; D006220:Haloperidol; D015107:4-Butyrolactone