Cocaine or selective block of dopamine transporters influences multisecondoscillations in firing rate in the globus pallidus

Previous studies have shown that direct-acting dopamine agonists modulate t he multisecond oscillations which are present in globus pallidus spike trai ns in vivo in awake rats. To investigate possible modulation by endogenous dopamine and by other monoamines, and by drugs with abuse potential, cocain e or selective monoamine uptake blockers were injected systemically during extracellular recording of single globus pallidus neurons and the results a nalyzed with spectral and wavelet methods. Both cocaine and the selective d opamine uptake blocker GBR-12909 significantly shortened the period of mult isecond oscillations, as well as increasing overall firing rate. Cocaine ef fects were blocked by dopamine antagonist pretreatment, as well as by N-met hyl-D-aspartate receptor antagonist (MK-801) pretreatment. Desipramine and fluoxetine (blockers of norepinephrine and serotonin uptake, respectively) had no significant effects on multisecond oscillations. The results suggest that dopamine has a primary role among monoamines in modulating multisecon d oscillations in globus pallidus activity, and that tonic dopaminergic and glutamatergic transmission is necessary for normal slow oscillatory functi on. [Neuropsychopharmacology 25:28-40, 2001] (C) 2001 American College of N europsychopharmacology. Published by Elsevier Science Inc.