Pharmacological manipulations of the substantia innominata-cortical cholinergic pathway.
The present study examined the effects of various pharmacological agents on the activity of cholinergic neurons within the nucleus basalis that are located in the substantia innominata (SI) and send afferent projections to the neocortex. Male Sprague-Dawley rats received microinfusions of selected compounds into the SI via a chronic indwelling cannula. In vitro sodium-dependent high affinity choline uptake (SDHACU) was determined in the frontal cortex 50 min later as an indicator of the changes in in vivo activity of cholinergic cells in the SI. GABAergic and opiate agonists, muscimol and enkephalin respectively, decreased neocortical SDHACU. Glutamate increased neocortical SDHACU. Noradrenergic, dopaminergic and serotonergic manipulations did not produce significant changes. These results suggest a regulatory role for enkephalinergic, GABAergic and glutamatergic afferents onto the basal forebrain cholinergic system within the SI.
D000818:Animals; D001479:Basal Ganglia / Q000187:drug effects*; D002540:Cerebral Cortex / Q000187:drug effects*; D002794:Choline / Q000378:metabolism; D004745:Enkephalins / Q000494:pharmacology; D005971:Glutamates / Q000494:pharmacology; D007099:Imipramine / Q000494:pharmacology; D008297:Male; D009118:Muscimol / Q000494:pharmacology; D009433:Neural Inhibition; D009434:Neural Pathways / Q000187:drug effects; D018377:Neurotransmitter Agents / Q000502:physiology; D010275:Parasympathetic Nervous System / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D017981:Receptors, Neurotransmitter / Q000502:physiology; D013377:Substantia Innominata / Q000187:drug effects*; D005680:gamma-Aminobutyric Acid / Q000502:physiology
D004745:Enkephalins; D005971:Glutamates; D018377:Neurotransmitter Agents; D017981:Receptors, Neurotransmitter; D009118:Muscimol; D005680:gamma-Aminobutyric Acid; D002794:Choline; D007099:Imipramine