Possible interaction of cholinergic and GABAergic systems between MS and CA1 upon memory acquisition in rats.
The present study explored the possibility that cholinergic and GABAergic systems of medial septum (MS) might influence acquisition of memory by regulation of acetylcholine (Ach) and γ-aminobutyric acid (GABA) receptors function in hippocampus and vice versa. The step-through passive avoidance (PA) task was used. The results showed that pre-training intra-MS/CA1 administration of nonselective muscarinic Ach antagonist, scopolamine (0.5, 1 and 2 μg/rat) and GABA(A) receptor agonist, muscimol (0.01 and 0.02 μg/rat) impaired, while acetylcholinesterase inhibitor, physostigmine (0.5 and 1 μg/rat) and GABA(A) receptor antagonist, bicuculline (0.25 μg/rat) improved memory acquisition. Moreover, intra-CA1/MS administration of a subthreshold dose of muscimol or bicuculline increased and reversed the impairment induced by scopolamine in MS/CA1 respectively (cross injection). Also, the result revealed that, intra-CA1/MS administration subthreshold dose of muscimol reduced improvement of memory induced by physostigmine in the MS/CA1, respectively (cross injection). On the other hand, subthreshold dose of bicuculline in CA1/MS did not alter memory improvement induced by physostigmine in the other site (MS/CA1). In conclusion, both cholinergic and GABAergic systems not only seem to play a role in the modulation of memory in the MS and CA1 but also to have a complex interaction.
Department of Neuroscience, School of Advance Medical Technologies, Tehran, Iran.
Behnam
B
Yousefi
Mohammad
M
Nasehi
Fatemeh
F
Khakpai
Mohammad Reza
MR
Zarrindast
D000704:Analysis of Variance; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D001640:Bicuculline / Q000494:pharmacology; D056547:CA1 Region, Hippocampal / Q000187:drug effects / Q000378:metabolism*; D018678:Cholinergic Agents / Q000378:metabolism*; D018680:Cholinergic Antagonists / Q000494:pharmacology; D002800:Cholinesterase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D058785:GABA-A Receptor Agonists / Q000494:pharmacology; D058787:GABA-A Receptor Antagonists / Q000494:pharmacology; D008297:Male; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D011939:Mental Recall / Q000187:drug effects; D009043:Motor Activity / Q000187:drug effects; D009118:Muscimol / Q000494:pharmacology; D009434:Neural Pathways / Q000187:drug effects / Q000502:physiology*; D010830:Physostigmine / Q000031:analogs & derivatives / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000187:drug effects; D012601:Scopolamine / Q000494:pharmacology; D020665:Septum of Brain / Q000187:drug effects / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D018678:Cholinergic Agents; D018680:Cholinergic Antagonists; D002800:Cholinesterase Inhibitors; D058785:GABA-A Receptor Agonists; D058787:GABA-A Receptor Antagonists; C026718:physostigmine salicylate; D009118:Muscimol; D005680:gamma-Aminobutyric Acid; D010830:Physostigmine; D012601:Scopolamine; D001640:Bicuculline