Effects of alpha 2-drugs and pilocarpine on the high-voltage spindle activity of young and aged control and DSP4-lesioned rats.
The present study investigates the effects of alpha 2-drugs and pilocarpine on the neocortical high-voltage spindle (HVS) activity in young and aged control and DSP4-lesioned rats. DSP4 partially decreased cortical and thalamic noradrenaline levels, but had no effect on HVS activity. The alpha 2-adrenoceptor agonist guanfacine (0.004, 0.02, 0.1 mg/kg) increased HVS activity in young and aged control and DSP4-lesioned rats. Guanfacine produced a significantly smaller increase in HVS activity in aged rats. A combination of pilocarpine (3 mg/kg), a muscarinic agonist, and atipamezole (1 mg/kg), an alpha 2-adrenoceptor antagonist, suppressed HVS activity more effectively than either of the drugs alone in young or aged control and DSP4-lesioned rats. The present results demonstrate that 1) the alpha 2-adrenoceptor antagonist and muscarinic agonist interact in suppressing HVSs in noradrenergically lesioned young and aged rats; 2) alpha 2-adrenoceptor agonists produce a greater increase in HVS activity in young than aged rats; and 3) partial noradrenergic lesions do not affect the HVS-modulating effects of alpha 2-adrenoceptor active drugs in young or aged rats.
Department of Neurology, University of Kuopio, Finland.
P
P
Riekkinen
J
J
Sirviö
P
P
Jäkälä
M
M
Riekkinen
R
R
Lammintausta
P
P
Riekkinen
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000375:Aging / Q000502:physiology*; D000818:Animals; D001596:Benzylamines / Q000494:pharmacology*; D001931:Brain Mapping; D004569:Electroencephalography / Q000187:drug effects*; D005071:Evoked Potentials / Q000187:drug effects / Q000502:physiology; D005625:Frontal Lobe / Q000187:drug effects* / Q000502:physiology*; D016316:Guanfacine / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D008125:Locus Coeruleus / Q000187:drug effects* / Q000502:physiology*; D008297:Male; D009434:Neural Pathways / Q000187:drug effects / Q000502:physiology; D009638:Norepinephrine / Q000502:physiology; D010862:Pilocarpine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011941:Receptors, Adrenergic / Q000187:drug effects* / Q000502:physiology*; D011976:Receptors, Muscarinic / Q000187:drug effects / Q000502:physiology; D012894:Sleep Stages / Q000187:drug effects* / Q000502:physiology*; D013566:Sympathomimetics / Q000494:pharmacology*; D013787:Thalamic Nuclei / Q000187:drug effects* / Q000502:physiology*
D000317:Adrenergic alpha-Antagonists; D001596:Benzylamines; D007093:Imidazoles; D011941:Receptors, Adrenergic; D011976:Receptors, Muscarinic; D013566:Sympathomimetics; D010862:Pilocarpine; C050701:atipamezole; D016316:Guanfacine; C012102:DSP 4; D009638:Norepinephrine