phenytoin  (Alomone Labs)

Journal: Neuropharmacology

Article Title: The critical role of persistent sodium current in hippocampal gamma oscillations

doi: 10.1016/j.neuropharm.2019.107787

Figure Lengend Snippet: Phenytoin reduces I NaP in PVBCs. (A) A representative reconstruction of an anatomically and neurochemically identified PVBC. The cell was filled with biocytin during whole-cell patch-clamp recordings and was imaged using a Zeiss confocal microscope. Axon arbors were restricted to the pyramidal cell layer of the CA1 region, whereas the dendrites covered most CA1 layers. The recorded PV+ cell showed tdTomato (TOM, thus PV+, right column). Ori., stratum oriens; Pyr., stratum pyramidale; Rad., stratum radiatum. (B) Under control conditions in the presence of synaptic blockers, a neurochemically identified PVBC manifested current responses to voltage ramps (−80 mV to −20 mV, 50 mVs −1 ) before (black trace) and during (red trace) bath application of TTX (1 μM). The subtracted current was referred to as I NaP (green trace). (C, D) In slices pretreated with phenytoin, similar voltage ramps produced negligible I NaP (C) or reduced I NaP (D) in neurochemically identified PVBCs. (E) Summary data of I NaP peak current values. Numbers in bar graph indicate number of PVBCs. (F, G) The TTX-subtracted current responses ( I NaP ) shown in B and C were converted to conductance in F and G, respectively. Note that there was negligible conductance in the PVBC, which was recorded from a hippocampal slice pretreated with phenytoin. * p

Article Snippet: APV, NBQX, and phenytoin were obtained from Alomone Labs (Jerusalem, Israel)., SR95531, and tetrodotoxin were purchased from Tocris Bioscience (Ellisville, MO, USA).

Techniques: Patch Clamp, Microscopy, Produced

Journal: Neuropharmacology

Article Title: The critical role of persistent sodium current in hippocampal gamma oscillations

doi: 10.1016/j.neuropharm.2019.107787

Figure Lengend Snippet: Phenytoin reduces I NaP in CA1 pyramidal cells. (A) section for the details). Dendrites of the recorded pyramidal cell covered most CA1 layers. The soma was located in the pyramidal cell layer. Ori., stratum oriens; Pyr., stratum pyramidale; Rad., stratum radiatum; L.M., stratum lacunosum-moleculare. (B) Under control conditions in the presence of synaptic blockers, voltage ramps (−80 mV to −20 mV, 50 mVs −1 ) were used to evoke I NaP in a pyramidal cell. (C) In a hippocampal slice pretreated with phenytoin, similar voltage ramps produced a decrease in I NaP of a pyramidal cell. (D) Summary data of I NaP peak current values. Numbers in the bars indicate number for pyramidal cells. (E, F) The TTX-subtracted current responses ( I NaP ) shown in B and C were converted to conductance in E and F, respectively. Note that there was lower amplitude conductance in the pyramidal cell, which was recorded from a hippocampal slice pretreated with phenytoin, compared to that in the pyramidal cell, which was recorded from a hippocampal slice pretreated with DMSO control ACSF. * p

Article Snippet: APV, NBQX, and phenytoin were obtained from Alomone Labs (Jerusalem, Israel)., SR95531, and tetrodotoxin were purchased from Tocris Bioscience (Ellisville, MO, USA).

Techniques: Produced

Journal: Neuropharmacology

Article Title: The critical role of persistent sodium current in hippocampal gamma oscillations

doi: 10.1016/j.neuropharm.2019.107787

Figure Lengend Snippet: Phenytoin reduces excitability of CA1 pyramidal cells. (A) Examples of APs from pyramidal cells (1 s-long pulses, +150 pA, 200 pA, or +500 pA from −65 mV). The voltage traces displayed in the left column were from a pyramidal cell in a hippocampal slice pretreated with DMSO control ACSF, whereas the voltage traces shown in the right column were from a pyramidal cell in a hippocampal slice pretreated with phenytoin. (B) Summary of the firing frequency of the recorded pyramidal cells. (C) Summary of the rheobase of the recorded pyramidal cells. Numbers in the bars represents number for pyramidal cells. * p

Article Snippet: APV, NBQX, and phenytoin were obtained from Alomone Labs (Jerusalem, Israel)., SR95531, and tetrodotoxin were purchased from Tocris Bioscience (Ellisville, MO, USA).

Techniques:

Journal: Neuropharmacology

Article Title: The critical role of persistent sodium current in hippocampal gamma oscillations

doi: 10.1016/j.neuropharm.2019.107787

Figure Lengend Snippet: Antioscillatory effects of phenytoin on hippocampal gamma oscillations. (A, B, C, D) CA1 gamma oscillations evoked by light ramps before and during bath application of phenytoin (A, 40 μM; C, 100 μM). Light ramps were delivered to the CA1 region every 2 min for 40 min of LFP recording sessions. The power spectra in B and D were constructed from the 1.4 s-long LFP traces shown in A and C, respectively. (E) Normalized gamma power before and during bath application of phenytoin (10 min control period followed by 30 min drug period). Note that gamma oscillations were stable in DMSO control ACSF over 40 min, but oscillations were reduced by therapeutic concentrations of phenytoin ( i.e. , 40 μM and 100 μM). (F) Gamma power during drug application (30-40 min shown in E) and DMSO control period (30-40 min) normalized to gamma power prior to drug exposure (0-10 min). Numbers in the bars indicate numbers of hippocampal slices used for phenytoin or DMSO control experiments. (G) Normalized peak frequencies of gamma oscillations. Note that the peak frequencies were stable in DMSO control ACSF over 40 min, but they were reduced by phenytoin along with a decrease in gamma power. (H) Peak frequencies during drug application (30-40 min shown in G) and DMSO control period (30-40 min) normalized to peak frequencies prior to drug exposure (0-10 min). n.s., not significant; * p

Article Snippet: APV, NBQX, and phenytoin were obtained from Alomone Labs (Jerusalem, Israel)., SR95531, and tetrodotoxin were purchased from Tocris Bioscience (Ellisville, MO, USA).

Techniques: Construct