cyclo sst  (Tocris)

Journal: The Journal of Neuroscience

Article Title: Somatostatin Inhibits Thalamic Network Oscillations In Vitro : Actions on the GABAergic Neurons of the Reticular Nucleus

doi: 10.1523/JNEUROSCI.22-13-05374.2002

Figure Lengend Snippet: SST activates K+-selective currents in RT neurons. A1, Current-clamp recording showing typical responses of an RT neuron to a series of current steps ranging from −150 to +100 pA. A2, Currents elicited in a voltage-clamped RT neuron by voltage ramps (−120 to −60 mV, over 1 sec) from a holding potential of −50 mV (holding current: −100 pA; 30 mm[K+]out) before, during, and after application of 500 nm SST application.B, Currents elicited by voltage ramps in an RT neuron in the absence (control and wash averaged) and presence of 500 nm SST in 2.5 mm (B1) and 30 mm [K+]out(B2). Superimposed traces inB2 also show the lack of effect of 100 nmCyclo-SST on K+ currents. Each current trace was averaged from 10 consecutive responses. Horizontal dashed lines in insets: 0 pA. Vertical dashed lines in each panel show expected K+-dependent reversal potentials for SST-evoked responses with [K+]in = 113 mm. Insets, SST-sensitive currents obtained by subtracting normalized control [(control + wash)/2] from SST traces. Calibration: B1 inset, 10 mV, 150 pA; B2 inset, 30 mV, 300 pA. Vertical dashed lines in B1 and B2 insetsindicate reversal potential of −87 and −50 mV, respectively.C1, Normalized current amplitude at −130 mV with 30 mm [K+]out in control solution and during SST (100 nm) application and washout in 17 RT neurons. In this and the following figures, relative K+ current indicates the ratio of the holding currents at −130 mV in drug (e.g., SST, Ba2+, etc.) and control conditions. Dashed lines connect control and +SST responses for each cell. ●, Inhibition; ○, enhancement.C2, Mean K+ current in control solution and after perfusion of SST (n = 28; **p < 0.01 vs control), 100 nmoctreotide (n = 6; p < 0.05 vs control), 100 nm Bim23052 (n = 5; **p < 0.01 vs control), or SST + Cyclo-SST (n = 6; not significant vs control).

Article Snippet: Concentrated cyclo-SST (Peninsula Labs), BIM23052 ( d -Phe-Phe-Phe- d -Trp-Lys-Thr-Phe-Thr-NH2), nc8–12 [ d -Phe-c(Cys-Tyr- d -Trp-Lys-Abu-Phe), locally synthesized], and octreotide ( d -Phe-Cys-Phe-DTrp-Lys-Thr-Cys-Thr-ol; American Peptide, Sunnyvale, CA) solutions were also stored at −70°C.

Techniques: Inhibition

Journal: The Journal of Neuroscience

Article Title: Somatostatin Inhibits Thalamic Network Oscillations In Vitro : Actions on the GABAergic Neurons of the Reticular Nucleus

doi: 10.1523/JNEUROSCI.22-13-05374.2002

Figure Lengend Snippet: Effects of SST receptor agonists and baclofen on whole-cell Ca2+ currents. A, Whole-cell voltage-gated Ca2+ currents evoked in an RT neuron by voltage steps from a holding potential of −90 mV (A1) or −70 mV (A2) to test potentials between −80 and +10 mV. A3,I–V curves measured from peak Ca2+ currents in A1 andA2 showing combined LVA and HVA current amplitudes (●) or HVA currents (○). B1, LVA (●) and HVA (○) currents that were elicited in an RT neuron by command steps of −60 and −20 mV from holding potentials of −90 and −70 mV, respectively. HVA currents (and their associated tail currents) were specifically reduced by 500 nm SST (arrow).Inset, HVA Ca2+ tail currents elicited in control (black trace) and SST (gray trace). Calibration: 2 msec, 400 pA.B2, Time-series measurements showing that the effects of SST were specific to HVA currents (○) and reversible in the same neuron. LVA currents (●) were unaffected. B3, Summary of effects of SST (100–500 nm), Bim23052 (200 nm), and baclofen (5 μm) on LVA and HVA currents in RT neurons (n = 29). **p < 0.01 vs control.

Article Snippet: Concentrated cyclo-SST (Peninsula Labs), BIM23052 ( d -Phe-Phe-Phe- d -Trp-Lys-Thr-Phe-Thr-NH2), nc8–12 [ d -Phe-c(Cys-Tyr- d -Trp-Lys-Abu-Phe), locally synthesized], and octreotide ( d -Phe-Cys-Phe-DTrp-Lys-Thr-Cys-Thr-ol; American Peptide, Sunnyvale, CA) solutions were also stored at −70°C.

Techniques: