Abstract
1. Voltage- and current-clamp intracellular recordings were performed on rat CA3 hippocampal pyramidal cells in a slice preparation. 2. Under current-clamp conditions, 5-hydroxytryptamine (5-HT) or baclofen (BAC) perfusion hyperpolarized CA3 cells. 3. Under single-electrode voltage-clamp conditions, 5-HT perfusion elicited an outward current flow that was blocked by 2 mM BaCl2 but not by 100 microM CdCl2. 4. The Emax of the current response in CA3 was larger than that elicited in CA1 and the potency was less in CA3 than CA1. 5. Increasing the external potassium concentration shifted the reversal potential for the 5-HT-mediated response. 6. The potassium current exhibited inward rectification. 7. The BAC- and 5-HT-mediated currents were not additive. 8. Pertussis-toxin (PTX) treatment blocked both 5-HT- and BAC-elicited hyperpolarizations. 9. On the basis of these results, we conclude that 5-HT hyperpolarized hippocampal CA3 pyramidal cells by increasing an inward-rectifying potassium conductance. Furthermore both the 5-HT1A and gamma-aminobutyric acidB (GABAB) receptors are linked to potassium channels via a PTX-sensitive G protein.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
