title: Quantifying altered long-term potentiation in the CA1 hippocampus.
abstract: Long-term potentiation (LTP) of synaptic transmission is a widely accepted model of learning and memory. In vitro brain slice techniques were used to investigate the effects of cortical-spreading depression and picrotoxin, an antagonist of the gamma-aminobutyric acid A (GABA(A)) receptor, on the tetanus-induced long-term potentiation of field excitatory postsynaptic potentials. Cortical-spreading depression is involved in glutamate desensitization; on the other hand, GABA(A) antagonists could increase postsynaptic excitability. This study shows that picrotoxin effectively induced long-term potentiation with 142.25 ± 4.18% of the baseline in the picrotoxin group (n = 8) versus 134.36 ± 2.35% of the baseline in the control group (n = 10). In group with picrotoxin applied to CSD, we obtained the smallest magnitude of LTP (120.15 ± 3.73% of the baseline, n = 8). These results suggest that picrotoxin could increase hippocampal activity and LTP; on the contrary, CSD reduced LTP magnitude. In addition, the results also suggest that the decay rate of post-tetanic potentiation has a direct relationship with LTP. Moreover, data were interpreted by nonlinear least squares quantifying, and LTP could also be quantified. The nonlinear attribute of LTP had an influence on the fitting, with respect to increasing the accuracy of the parameters and the compatibility of combination of stimuli that produce LTP.
authors.affiliation: Biomedical Engineering Program, Faculty of Engineering, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok, Thailand 10330.
authors.forename: T
authors.initials: T
authors.lastname: Saleewong
authors.forename: A
authors.initials: A
authors.lastname: Srikiatkhachorn
authors.forename: M
authors.initials: M
authors.lastname: Maneepark
authors.forename: A
authors.initials: A
authors.lastname: Chonwerayuth
authors.forename: S
authors.initials: S
authors.lastname: Bongsebandhu-phubhakdi
mesh_terms: D000818:Animals; D056547:CA1 Region, Hippocampal / Q000187:drug effects* / Q000502:physiology*; D013181:Cortical Spreading Depression / Q000187:drug effects / Q000502:physiology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D018756:GABA Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000502:physiology; D017774:Long-Term Potentiation / Q000187:drug effects* / Q000502:physiology*; D008297:Male; D008959:Models, Neurological; D017711:Nonlinear Dynamics; D009924:Organ Culture Techniques; D010852:Picrotoxin / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D011963:Receptors, GABA-A / Q000502:physiology
chemical_list: D018756:GABA Antagonists; D018698:Glutamic Acid; D010852:Picrotoxin; D011963:Receptors, GABA-A