Effect of stimulation of beta-adrenergic receptors on neuronal activity in primary motor cortex of the rat.
Modulatory influence of beta1- and beta2-subtypes of adrenergic receptors (ARs) on the background neuronal activity and cerebellocortical transmission was characterized in the rat primary motor cortex (M1). Microiontophoretic administration of non-selective beta-ARs agonist isoproterenol significantly decreased firing rate and responses to superior cerebellar peduncle stimulation in 82% of studied neurons in a dose-dependent manner. Similar changes were induced by ejection of selective beta1-ARs agonist dobutamine, while fenoterol (selective beta2-ARs agonist) increased or reduced firing rate in 32% and 19% of M1 neurons, respectively. Non-selective beta-ARs antagonist propranolol enhanced both the background and evoked activity in 84% of tested neurons. These data provided the functional evidence for beta-ARs-mediated inhibition (predominantly through beta1-subtype) of cerebellocortical input to M1. The possible mechanism of the positive therapeutic effect of propranolol in tremor-predominant Parkinson's disease is discussed.
Lukhanina
E P
EP
Department of Brain Physiology, Bogomoletz Institute of Physiology, 4, Bogomoletz Street, 01601 MSP, Kyiv, Ukraine. luh@srev.biph.kiev.ua
Kolomiets
B P
BP
Pilkevich
N A
NA
D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D004305:Dose-Response Relationship, Drug; D008297:Male; D009044:Motor Cortex / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D011943:Receptors, Adrenergic, beta / Q000502:physiology*
D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D011943:Receptors, Adrenergic, beta