hm1a  (Alomone Labs)

Journal: JCI Insight

Article Title: Developmental progression of respiratory dysfunction in a mouse model of Dravet syndrome

doi: 10.1172/jci.insight.184231

Figure Lengend Snippet: ( A – C ) Representative traces of firing rate from RTN neurons in slices from control (black) and Scn1a +/– (red) mice ( A ) and summary data show that bath application of Hm1a (50 μM) decreased baseline activity ( B ) and increased the firing response to 10% CO 2 ( C ) of RTN neurons in slices from Scn1a +/– mice. In contrast to this, Hm1a minimally affected baseline activity and CO 2 /H + sensitivity of RTN neurons in slices from control mice ( A – C ). ( D – F ) Traces of firing rate from RTN neurons in slices from control (black) and Scn1a +/– (red) mice ( D ) and summary data show that application of gabazine (GZ; 50 μM), picrotoxin (PX; 50 μM), and strychnine (ST; 1 μM) to inhibit GABA A and glycine receptors effectively reversed the effects of Hm1a on baseline activity ( E ) and CO 2 sensitivity ( F ) of RTN neurons in slices from Scn1a +/– mice. Comparisons were made using a paired t test within genotypes and an unpaired t test across genotypes. * P < 0.05.

Article Snippet: In some experiments, RTN slices were treated with Hm1a (Alomone Labs, STH-601) alone or Hm1a plus gabazine (Tocris, SR 95531), picrotoxin (Tocris, 1128), and strychnine (Sigma-Aldrich, S0532).

Techniques: Control, Activity Assay

Journal: JCI Insight

Article Title: Developmental progression of respiratory dysfunction in a mouse model of Dravet syndrome

doi: 10.1172/jci.insight.184231

Figure Lengend Snippet: ( A ) Segments of membrane potential and summary data plotted as spike discharge heatmaps (30-ms bins) from RTN neurons in slices from Scn1a +/+ (black, n = 8) and Scn1a +/– (red, n = 9) mice during depolarizing current injections (20 to 140 pA; 1-second duration) from a holding potential of –80 mV before and 10 minutes following bath application of Hm1a (50 μM). ( B ) Summary data plotted as mean ± SEM number of action potentials evoked by depolarizing current injection shows that under control conditions RTN neurons in slices from both genotypes have a diminished capacity to maintain firing during larger step depolarizations, with RTN neurons in slices from Scn1a +/– mice being significantly diminished compared with control during +120 pA steps. Hm1a improves sustained firing behavior of RTN neurons in slices from Scn1a +/– mice at +120 pA ( F 7,119 = 5.3) and +140 pA but not Scn1a +/+ neurons ( F 7,112 = 2.5, P = 0.48). Comparisons were made using 2-way ANOVA with Šídák’s multiple-comparison test. ( C ) Summary data (plotted as mean ± SEM) show that RTN neurons in slices from Scn1a +/+ and Scn1a +/– mice have similar resting membrane potential and input resistance (measured during –60 pA steps) under control conditions and during incubation in Hm1a. * P < 0.05, ** P < 0.01.

Article Snippet: In some experiments, RTN slices were treated with Hm1a (Alomone Labs, STH-601) alone or Hm1a plus gabazine (Tocris, SR 95531), picrotoxin (Tocris, 1128), and strychnine (Sigma-Aldrich, S0532).

Techniques: Membrane, Injection, Control, Comparison, Incubation

Journal: bioRxiv

Article Title: Potentiating Na V 1.1 in Dravet syndrome patient iPSC-derived GABAergic neurons increases neuronal firing frequency and decreases network synchrony

doi: 10.1101/2023.09.28.559990

Figure Lengend Snippet: a) At DIV 42, cultures were treated with drug or vehicle by pipette into cell culture media to achieve indicated concentrations. b) Plots of instantaneous spike frequency of cultures before and after treatments. Both muscimol and Hm1a halted the occurrence of recurring network bursts. c) Raster plot of spike events of 10 neurons on application of muscimol, each marker represents neuronal spike. d) Raster plot of spike events of 10 neurons on Hm1a (100 nM), each marker represents neuronal spike. Hm1a resulted in a dramatic increase of firing of multiple units and reduction of firing of others. e-g) Plots depicting neurons firing rate pre and post indicated treatment. The firing rate was calculated in 5 seconds bins over 30 seconds baseline and 30 seconds post treatment. h) The Δ frequency (Hz) was calculated as difference between treatment firing rate and baseline firing rate. Hm1a results in an increase in neuronal firing. i) Hm1a (100 nm) treatment resulted in an increase of percentage of neurons with detected bursting activity. Numbers in bar graph are total count of neurons. j) Mean burst duration of neurons 30 seconds before and 30 seconds after Hm1a (100 nM) treatment. k) Mean number of spikes per burst before and after Hm1a (100 nM) treatment. l) Neuron intraburst firing rate before and after Hm1a (100 nM) treatment. ns: no significant difference, * P <0.05, ** P < 0.01, **** P < 0.0001. Kruskal-Wallis test, followed by the Dunn-Sidák multiple-comparison test.

Article Snippet: The Na V 1.1 potentiator δ-theraphotoxin-Hm1a (Hm1a, Alomone Labs, #STH-601), used at 100 and 500 nM.

Techniques: Transferring, Cell Culture, Marker, Activity Assay, Comparison