Long-term depression in rat CA1-subicular synapses depends on the G-protein coupled mACh receptors.
The subiculum, which is the primary target of CA1 pyramidal neurons and sending efferent fibres to many brain regions, serves as a hippocampal interface in the neural information processes between hippocampal formation and neocortex. Long-term depression (LTD) is extensively studied in the hippocampus, but not at the CA1-subicular synaptic transmission. Using whole-cell EPSC recordings in the brain slices of young rats, we demonstrated that the pairing protocols of low frequency stimulation (LFS) at 3 Hz and postsynaptic depolarization of -50 mV elicited a reliable LTD in the subiculum. The LTD did not cause the changes of the paired-pulse ratio of EPSC. Furthermore, it did not depend on either NMDA receptors or voltage-gated calcium channels (VGCCs). Bath application of the G-protein coupled muscarinic acetylcholine receptors (mAChRs) antagonists, atropine or scopolamine, blocked the LTD, suggesting that mAChRs are involved in the LTD. It was also completely blocked by either the Ca2+ chelator BAPTA or the G-protein inhibitor GDP-beta-S in the intracellular solution. This type of LTD in the subiculum may play a particular role in the neural information processing between the hippocampus and neocortex.
Li
Hongbin
H
Laboratory of Learning and Memory, Kunming Institute of Zoology, The Chinese Academy of Sciences, Kunming 650223, PR China.
Zhang
Jichuan
J
Xiong
Wenyong
W
Xu
Tianle
T
Cao
Jun
J
Xu
Lin
L
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D001285:Atropine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002614:Chelating Agents / Q000494:pharmacology; D004347:Drug Interactions; D004533:Egtazic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D004558:Electric Stimulation / Q000379:methods; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018756:GABA Antagonists / Q000494:pharmacology; D006153:Guanosine Diphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D006624:Hippocampus / Q000166:cytology* / Q000187:drug effects; D066298:In Vitro Techniques; D036881:Long-Term Synaptic Depression / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009532:Nickel / Q000494:pharmacology; D009553:Nimodipine / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D010852:Picrotoxin / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011976:Receptors, Muscarinic / Q000502:physiology*; D012601:Scopolamine / Q000494:pharmacology; D013569:Synapses / Q000187:drug effects / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D013873:Thionucleotides / Q000494:pharmacology
D015763:2-Amino-5-phosphonovalerate; D001285:Atropine; D002118:Calcium; D002121:Calcium Channel Blockers; D002614:Chelating Agents; D004533:Egtazic Acid; D018691:Excitatory Amino Acid Antagonists; D018756:GABA Antagonists; D006153:Guanosine Diphosphate; D018727:Muscarinic Antagonists; D009532:Nickel; D009553:Nimodipine; D010852:Picrotoxin; D011976:Receptors, Muscarinic; D012601:Scopolamine; D013873:Thionucleotides; C023427:guanosine 5'-O-(2-thiodiphosphate); C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid