The cholinergic inhibition of afterhyperpolarization in rat hippocampus is independent of cAMP-dependent protein kinase.
The possible involvement of protein kinase A (PKA) in the muscarinic inhibition of the slow afterhyperpolarizing current (IAHP) was investigated in rat hippocampal pyramidal cells. IAHP was recorded using the whole cell method in hippocampal slices, and Rp-cAMPS, a PKA antagonist, was applied intracellularly. The inhibition of IAHP by carbachol was not affected by Rp-cAMPS. In contrast, Rp-cAMPS reduced the cAMP-dependent inhibition of IAHP by norepinephrine. The results show that phosphorylation by PKA does not contribute to the muscarinic effect on IAHP.
Blitzer
R D
RD
Department of Psychiatry, Mount Sinai Medical Center, New York, NY 10029.
Wong
T
T
Nouranifar
R
R
Landau
E M
EM
D000818:Animals; D002217:Carbachol / Q000494:pharmacology*; D000242:Cyclic AMP / Q000031:analogs & derivatives* / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009638:Norepinephrine / Q000494:pharmacology*; D017966:Pyramidal Cells / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013873:Thionucleotides / Q000494:pharmacology*; D013997:Time Factors
D013873:Thionucleotides; C016957:adenosine-3',5'-cyclic phosphorothioate; D002217:Carbachol; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D009638:Norepinephrine