Effects of lamotrigine on field potentials, propagation, and long-term potentiation in rat prefrontal cortex in multi-electrode recording.
Lamotrigine (LTG) is an anti-epileptic drug that is widely used clinically in various neuropsychiatric disorders. Although consensus is found on the general mode of action by LTG on voltage-gated sodium current, its effect on field potential, neuropropagation, and long-term potentiation, especially in prefrontal cortex (PFC), is still not understood completely. We investigated LTG effects on synaptic response in rat prefrontal cortical slice with the aid of a novel multi-electrode dish (MED64) system. The amplitude and propagation of field excitatory postsynaptic potentials (fEPSP), presynaptic fiber volleys (PrV) were expressed dimensionally in the MED64 system. Lamotrigine (3-100 microM) inhibited the amplitude and propagation of fEPSP and PrV in a concentration dependent manner. It exerted a predominant presynaptic action, as indicated by the increment in paired-pulse facilitation. Stimulating dependency with reduction fEPSP was seen in the presence of LTG at clinically relevant concentrations as well as with PrV, both in amplitude and propagation. In addition, the depression of PrV amplitudes in the presence of LTG showed a use-dependent fashion. As to LTP in PFC, it was not fEPSP amplitude but propagation reduced by LTG. In PFC, LTG exerts its use- and concentration-dependent inhibitory effect on presynaptic action and depresses fEPSP amplitude and propagation in a clinically relevant concentration. LTP was preserved in its fEPSP amplitude but not propagation in PFC in the presence of LTG.
Huang
Chin-Wei
CW
Department of Neurology, National Cheng-Kung University Medical Center, Tainan, Taiwan. huangcw@mail.ncku.edu.tw
Hsieh
Yi-Jung
YJ
Tsai
Jing-Jane
JJ
Huang
Chao-Ching
CC
D000704:Analysis of Variance; D000818:Animals; D001931:Brain Mapping; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D004558:Electric Stimulation / Q000379:methods; D004566:Electrodes; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects* / Q000528:radiation effects; D000077213:Lamotrigine; D017774:Long-Term Potentiation / Q000187:drug effects* / Q000528:radiation effects; D008297:Male; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D017397:Prefrontal Cortex / Q000187:drug effects*; D017729:Presynaptic Terminals / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D014227:Triazines / Q000494:pharmacology*
D002121:Calcium Channel Blockers; D014227:Triazines; D000077213:Lamotrigine