Interaction between the alpha 2-noradrenergic and muscarinic systems in the regulation of neocortical high voltage spindles.
The present experiments were carried out in order to study the interaction between alpha 2-noradrenergic and muscarinic systems in regulating high voltage spindle (HVS) activity in neocortex. Alpha 2-antagonist (atipamezole 1 and 10 mg/kg) blocked HVS activity. Atipamezole at 0.1 mg/kg dose had no effect on HVS activity. Alpha 2-agonist (guanfacine 0.004, 0.02 and 0.1 mg/kg) increased dose dependently HVSs. Guanfacine-induced HVSs were blocked by nucleus reticularis (NRT) lesions and by stimulation of either noradrenergic or cholinergic (pilocarpine) systems. Moreover, combined injections of atipamezole 1 mg/kg and pilocarpine 3 mg blocked HVSs more effectively than either of the drugs alone. Our results suggest that the NRT is jointly modulated by the noradrenergic and cholinergic afferents.
Riekkinen
P
P
Department of Neurology, University of Kuopio, Finland.
Sirviö
J
J
Jäkälä
P
P
Lammintausta
R
R
Riekkinen
P
P
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism* / Q000502:physiology; D004569:Electroencephalography; D005260:Female; D016316:Guanfacine / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D008125:Locus Coeruleus / Q000187:drug effects / Q000502:physiology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011941:Receptors, Adrenergic / Q000187:drug effects*; D011976:Receptors, Muscarinic / Q000187:drug effects*
D000317:Adrenergic alpha-Antagonists; D007093:Imidazoles; D011941:Receptors, Adrenergic; D011976:Receptors, Muscarinic; C050701:atipamezole; D016316:Guanfacine