Journal: Scientific Reports

Article Title: Venom composition and pain-causing toxins of the Australian great carpenter bee Xylocopa aruana

doi: 10.1038/s41598-022-26867-8

Figure Lengend Snippet: Pain-causing effects of X. aruana venom components. ( a,b ) Application of XYTX 1 -Xa1a (10 μM) to DRG cells produced an immediate and sustained, non-cell-specific increase in [Ca 2+ ] i . ( c ) Potency of XYTX 1 -Xa1a and melittin in F11 cells, as monitored by changes in [Ca 2+ ] i . ( d–f ) The increase in [Ca 2+ ] i caused by XYTX 1 -Xa1a was potentiated by the presence of venom PLA 2 (1 µM), but not XYTX 2 -Xa2a (1 μM). ** P < 0.01 (unpaired t -test). ( g,h ) Shallow intraplantar injection of XYTX 1 -Xa1a (200 pmol) caused spontaneous pain behaviours in mice which was potentiated by co-injection of venom PLA 2 (20 pmol), but not XYTX 2 -Xa2a (20 pmol). XYTX 2 -Xa2a (20 pmol) alone does not cause spontaneous pain behaviours while venom PLA 2 does (20 pmol). Data are expressed as mean ± SEM ( n = 3–6). ( i ) Co-injection of XYTX 1 -Xa1a (200 pmol) plus venom PLA 2 (20 pmol) caused paw swelling. Data are expressed as mean ± SEM ( n = 3–6). * P < 0.05; ** P < 0.01; **** P < 0.0001 (one way-ANOVA with Tukey’s multiple comparisons).

Article Snippet: F11 (mouse neuroblastoma \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\times $$\end{document} × DRG neuron hybrid; European Collection of Authenticated Cell Cultures) were cultured as previously described .

Techniques: Produced, Injection

Journal: Pflugers Archiv : European journal of physiology

Article Title: FHF2 isoforms differentially regulate Nav1.6 mediated resurgent sodium currents in dorsal root ganglion neurons

doi: 10.1007/s00424-016-1911-9

Figure Lengend Snippet: DRG neurons were transfected with Nav1.6r and FHF2A, FHF2B or fluorescent protein tag (control). a, Representative traces of cycle-dependent reduction as a measure of accumulation of long-term inactivation (LTI) for control (black), FHF2A (blue) and FHF2B (purple) groups. b, The percentage of channels available as a function of depolarization cycle shows overexpression of FHF2A (n=19) increased accumulation of long-term relative to control (n=28), whereas, FHF2B (n=13) did not. Activation, inactivation and recovery from inactivation were assayed with a series of standard protocols (see Methods sections). c, Normalized conductance (G/Gmax) as a function of voltage shows that FHF2A (blue squares, n=16) overexpression shifted the voltage dependence of activation relative to control (black circles, n=25). No change is observed for FHF2B overexpression (purple diamonds, n=11) relative to control. d, Normalized current (I/Imax) as a function of voltage shows that voltage dependence of inactivation was shifted to positive potentials in FHF2A (n=19) and FHF2B (n=13) groups relative to control (n=27). e, Fraction of channels available as a function of time shows FHF2A (n=19) overexpression greatly slowed recovery from inactivation relative to control (n=15), whereas, FHF2B (Inset, n=12) enhanced channel recovery. Abbreviations: LTI-Long-term Inactivation; Asterisks (*) represent p <0.0001 obtained from Student’s t-test. Data are mean ± SEM.

Article Snippet: Cell culture DRG neurons were obtained from adult male Sprague Dawley rats.

Techniques: Transfection, Control, Over Expression, Activation Assay

Journal: Pflugers Archiv : European journal of physiology

Article Title: FHF2 isoforms differentially regulate Nav1.6 mediated resurgent sodium currents in dorsal root ganglion neurons

doi: 10.1007/s00424-016-1911-9

Figure Lengend Snippet: a, Representative traces of Nav1.6r mediated resurgent currents obtained from cultured DRG neurons with corresponding peak resurgent currents highlighted for control (black), FHF2A overexpression (blue) and FHF2B overexpression (purple) conditions. b, The distribution of resurgent current positive (+INaR)/resurgent current negative (−INaR) DRG neurons was not different with FHF2B (n=13) overexpression relative to control (n=29). FHF2A (n=18) overexpression significantly decreased the percentage of DRG neurons that generated resurgent currents relative to control (p<0.0005, X2 test). c, Normalized resurgent current amplitude as a function of voltage shows FHF2A overexpression (blue squares) decreased resurgent current amplitude in a range of voltages relative to control (black circles). In contrast, FHF2B overexpression (purple triangles) increased resurgent current amplitude in a range of voltages. Asterisks (*) represent p <0.05 obtained from Student’s t-test. Data are mean ± SEM.

Article Snippet: Cell culture DRG neurons were obtained from adult male Sprague Dawley rats.

Techniques: Cell Culture, Control, Over Expression, Generated

Journal: Pflugers Archiv : European journal of physiology

Article Title: FHF2 isoforms differentially regulate Nav1.6 mediated resurgent sodium currents in dorsal root ganglion neurons

doi: 10.1007/s00424-016-1911-9

Figure Lengend Snippet: Nav1.6r currents were isolated in DRG neurons and recordings were obtained in the presence (+) or absence (−) of FHFA peptide in the recording pipette. Representative traces of cycle-dependent reduction as a measure of accumulation of long-term inactivation (LTI) are shown for −FHFA peptide group (a, black) and +FHFA peptide group (b, pink). c, The percentage of channels available as a function of depolarization cycles shows that addition of the FHFA peptide (black circles, n=15) significantly increased accumulation of channels in long-term inactivated states relative to −FHFA peptide group (pink squares, n=14). d, Recovery from inactivation was greatly slowed in +FHFA peptide group (n=15) relative to −FHFA peptide group (n=14). e, Representative traces of Nav1.6r mediated resurgent currents with peak currents highlighted for −FHFA peptide (black) and +FHFA peptide (pink) groups. f, Compared to −FHFA peptide (black circles, n=15), addition of the FHFA peptide (pink squares, n=16) reduced resurgent current amplitude. Note resurgent currents were normalized to peak transient currents and plotted as a function of voltage. Abbreviations: LTI-Long-term Inactivation. Asterisks (*) represent p<0.05 obtained from Student’s t-test. Data are mean ± SEM.

Article Snippet: Cell culture DRG neurons were obtained from adult male Sprague Dawley rats.

Techniques: Isolation, Transferring

Journal: Pflugers Archiv : European journal of physiology

Article Title: FHF2 isoforms differentially regulate Nav1.6 mediated resurgent sodium currents in dorsal root ganglion neurons

doi: 10.1007/s00424-016-1911-9

Figure Lengend Snippet: Activation, inactivation and recovery from inactivation were assayed with a series of standard protocols (see Methods sections). a, Representative traces of cycle-dependent reduction as a measure of long-term inactivation (LTI) for Nav1.6r isolated currents in DRG neurons with co-expression of fluorescent tag (control, black), F2A(β4) (green) and β4-F2A (orange). b, The percentage of channels available as a function of depolarization cycle shows increased accumulation of long-term inactivation for β4(F2A) group (orange squares, n=12) relative to control (black circles, n=16), whereas no difference is observed for F2A(β4) group (green triangles, n=8) relative to control. c, Normalized conductance as a function of voltage shows that co-expression of F2A(β4) (n=8) shifted the voltage dependence of activation to positive potentials relative to control (n=14), whereas, no change is observed for the β4(F2A) group (n=12). d, Normalized current as a function of voltage shows that co-expression of F2A(β4) (n=9) shifted the voltage dependence of steady-state inactivation to positive potentials relative to control (n=14), whereas, no change is observed for the β4(F2A) group (n=12). e, Fraction of current available as a function of time shows that recovery is not significantly altered with co-expression of either chimera β4(F2A) (n=12) or F2A(β4) (n=9) relative to control (n=14). Asterisks (*) represent p<0.05 obtained from Student’s t-test. Data are mean ± SEM.

Article Snippet: Cell culture DRG neurons were obtained from adult male Sprague Dawley rats.

Techniques: Activation Assay, Isolation, Expressing, Control

Journal: Pflugers Archiv : European journal of physiology

Article Title: FHF2 isoforms differentially regulate Nav1.6 mediated resurgent sodium currents in dorsal root ganglion neurons

doi: 10.1007/s00424-016-1911-9

Figure Lengend Snippet: a, Representative traces of Nav1.6r mediated resurgent currents obtained from cultured DRG neurons with corresponding peak resurgent currents highlighted for control (black), β4(F2A) (orange) and F2A(β4) (green) groups. b, Neither co-expression of (β4)F2A (n=12) nor co-expression of F2A(β4) (n=9) altered the distribution of resurgent current positive (+INaR)/resurgent current negative (−INaR) DRG neurons relative to control (n=16). c, Resurgent current amplitude was decreased with co-expression of β4(F2A) (orange squares, n=12) in a range of voltages relative to control (black circles, n=15). In contrast, co-expression of F2A(β4) (green triangles, n=9) chimera increased resurgent current amplitude in a range of voltages relative to control. Note that resurgent currents were normalized to peak transient currents and plotted as a function of voltage. Asterisks (*) represent p <0.05 obtained from Student’s t-test. Summary data are mean ± SEM.

Article Snippet: Cell culture DRG neurons were obtained from adult male Sprague Dawley rats.

Techniques: Cell Culture, Control, Expressing

Journal: Pflugers Archiv : European journal of physiology

Article Title: FHF2 isoforms differentially regulate Nav1.6 mediated resurgent sodium currents in dorsal root ganglion neurons

doi: 10.1007/s00424-016-1911-9

Figure Lengend Snippet: Examples of immunocytochemical staining for FHFAs in primary cultured DRG neurons from control (sham operated, a) and induced local inflammation of the DRGs (LID, b) animals post-operative day 5. c, DRG neurons from LID animals (n=1989) exhibited an increase in FHFA signal relative to sham control (n=1116). Examples of immunocytochemical staining for FHF2B in primary cultured DRG neurons from control (sham operated, d) and induced local inflammation of the DRGs (LID, e) animals post-operative day 5. f, DRG neurons from LID animals (n=1164) exhibited a decrease in FHF2B signal relative to sham control (n=1121). Five animals per group were examined. Asterisks (*) represent p <0.0001 obtained from Student’s t-test. Summary data are mean ± SEM. Scale bar 50 μm.

Article Snippet: Cell culture DRG neurons were obtained from adult male Sprague Dawley rats.

Techniques: Staining, Cell Culture, Control

Journal: Pflugers Archiv : European journal of physiology

Article Title: FHF2 isoforms differentially regulate Nav1.6 mediated resurgent sodium currents in dorsal root ganglion neurons

doi: 10.1007/s00424-016-1911-9

Figure Lengend Snippet: a-b, No spontaneous activity (-SA) was detected on DRG neurons from sham rats when 1 mM FHFA (n = 10) or 1 mM 5Q (n = 12) was included in the pipette solution. c-d, 30% of DRG neurons from local inflammation of the DRGs (LID) rats showed spontaneous activity (+SA) in the presence of 1 mM 5Q (n = 10), while no spontaneous activity was observed in the presence of 1 mM FHFA (n = 14). Representative action potential traces induced by a 2-s injection of 400 pA current on DRG neurons from sham (e) and LID (f) rats in the presence of 1 mM 5Q (left panel) or 1 mM FHFA (right panel). f and h, average number of action potentials induced by 2-s injection of currents ranging from 100 – 500 pA.

Article Snippet: Cell culture DRG neurons were obtained from adult male Sprague Dawley rats.

Techniques: Activity Assay, Transferring, Injection