However, these two factors will tend to balance each other out as the development of the endolymphatic potential will increase the MT current to offset EX 527 cell line the growth in the K+ conductance over the same period (P11–P19). It might be argued that the standing MT current and the depolarization elicited during bundle perfusion with low Ca2+ solution are an artifact of the local perfusion system, perhaps due to damage to the
OHCs or exposure of the basolateral membrane to high K+. This seems unlikely for the following reasons: (1), any nonspecific leak current or depolarization could be abolished with 0.2 mM DHS (Figure 2 and Figure 4) that blocks the MT channel without affecting the voltage-sensitive K+ current; indeed perfusion with DHS was used to define
the nontransducer dependent leak current; (2), OHCs showed a hyperpolarized resting membrane potential (negative to −60 mV) in conditions that turned off the MET current, which indicates the presence of healthy cells; (3), comparison of the fraction of MT current on at rest in rat and gerbil gave the same value (0.46) irrespective 3-deazaneplanocin A mouse of whether the low Ca2+ endolymph was accompanied by K+ or Na+, which have similar permeability through the MT channel (Ohmori, 1985); furthermore, membrane potentials in gerbil OHCs (Figure 4) were measured with a Na+-based endolymph; and (4), the standing current, however, relied on the nature of the intracellular mobile Ca2+ buffer and was smaller with EGTA than with BAPTA (Figure 3). The distinction between BAPTA and EGTA largely reflects a difference in the
rate of Ca2+ binding, BAPTA being much faster in lowering the Ca2+ near the internal face of the MT channel (Ricci et al., 1998). This accounts for the difference in the fraction of MT channels open at rest and in resting potential between OHCs (endogenous Ca2+ buffer equivalent to 1 mM BAPTA; Beurg et al., 2010) and IHCs (1 mM EGTA; Johnson et al., 2008). The OHC resting potentials in endolymphatic Ca2+ reported here differ from earlier measurements using other types of preparation and experimental conditions. Most studies on isolated organs of Corti or solitary OHCs have reported resting potentials of −60 to −70 mV (e.g., −57 mV, nearly Housley and Ashmore, 1992; −64 mV, Preyer et al., 1994; −70 mV, Mammano and Ashmore, 1996; −60 mV, Marcotti and Kros, 1999). In those recordings, receptor potentials were only a few millivolts (Preyer et al., 1994) or not reported, suggesting a small standing MT current, a view supported by the more hyperpolarized membrane potential of OHCs obtained on turning off the MET current (Figure 2 and Figure 4) or tip link destruction. The preparation most similar to that used here is the hemi-cochlea (He et al., 2004), which gave a mean OHC resting potential of −57 mV and a maximum receptor potential of 30 mV in the presence of 1.6 mM extracellular Ca2+.
M1:y=CHM2:y=CH+AONM3:y=CH+AON+AOCM4:y=CH+AON+AOC+HONM5:y=CH+AON+AOC+HON+HOC. None of the variables related to the actual outcome of the animal’s choice were included in M1, whereas all of them were included in M3. Therefore, a given neuron was considered encoding actual outcomes, if the
neural activity was better accounted for by M3 than by M1 (partial F-test, p < 0.05; Kutner et al., 2005). Similarly, a neuron was considered encoding hypothetical outcomes if M5 accounted for the firing rates better than M3. Whether a given neuron differentially modulated their activity according to the actual outcomes from specific targets was tested by comparing M2 and M3, whereas the effects of hypothetical outcomes related to specific Selleckchem AZD5363 targets were evaluated by comparing M4 and M5 (partial F-test, p < 0.05). In the analyses described Cell Cycle inhibitor above (M1 through M5), the regressors related to actual or hypothetical outcomes and their conjunctions with the animal’s choice were introduced separately to test whether neural activity was differentially modulated by the outcomes from different actions. To estimate the effect of actual winning payoff from each target on neural activity, we applied the following model separately to a set of winning trials in which the animal chose a particular target. M6:y=bo+bqQwin,where Qwin denotes the winning payoff from the
chosen target (Qwin = 2, 3, or 4). Similarly, the effect of the hypothetical payoff from a given target was estimated by applying the following model to a different subset of trials in which the animal chose Sodium butyrate one of the remaining two targets and did not win (lost or tied). M7i:y=bo+buU+bhHwin,where U is the dummy variable indicating which of the two remaining targets was chosen by the animal (e.g., U = 0 and 1 for the left and right targets, respectively, when analyzing the trials with the winning target at the top), and Hwin now denotes the hypothetical payoff from the unchosen winning target (2, 3, or 4).
For experiment I, it was not necessary to introduce a separate regressor for the actual outcome in this model (M7i), because the animal’s choice also determined the actual payoff (see the top panels in Figure 3). In contrast, for experiment II, it is necessary to factor out the changes in neural activity related to the animal’s choice and its actual outcome separately. Therefore, the following model was applied to estimate the effect of the hypothetical payoff in experiment II. M7ii:y=U1×(bloss1Oloss+btie1Otie)+U2×(bloss2Oloss+btie2Otie)+bhHwin,where U1 and U2 are the dummy variables indicating animals’ choice which resulted in loss or tie. The effect size for the activity related to actual and hypothetical outcomes are estimated using the standardized regression coefficients.
In the tracheae, it negatively regulates several
growth factor RTK orthologs, and it associates with EGFR in cultured cells (Jeon et al., 2012; Jeon and Zinn, 2009). It also has the C-terminal YxNΦ motif. Ptp10D single mutants have no known embryonic phenotypes, but Ptp10D genetically interacts with other Rptp genes. The analysis of Ptp10D Ptp69D double mutants demonstrated that Ptp10D is involved in the control of axon guidance across the midline of the CNS ( Sun et al., 2000, 2001). Double mutants lacking both Ptp10D and the other type III RPTP, Ptp4E, Onalespib mw have unique defects in tracheal tube formation in which unicellular tubes are converted into spherical cysts ( Jeon and Zinn, 2009). In this paper, we show that Ptp10D
binds to Sas in embryos and in vitro. Loss-of-function (LOF) genetic interaction studies show TSA HDAC purchase that Sas and Ptp10D act together in neurons to control longitudinal axon guidance. Signaling by Sas in glia is negatively regulated by its interactions with Ptp10D on neurons. To find potential ligands and coreceptors for Ptp10D, we used 10D-AP to stain embryos that ectopically expressed CSS proteins. The set of lines for CSS protein expression was originally assembled by creating a database of 976 CSS proteins that includes more than 80 types of XC domains, then collecting lines bearing insertions of UAS-containing (EP-like) elements in the 5′ ends of 410 of the genes (Kurusu et al., 2008). A total of 311 of these lines, representing all genes encoding plausible ligand candidates (Table S1 available online), were crossed to a line bearing two GAL4 drivers, Elav-GAL4 (panneuronal) and 24B-GAL4 (pan-muscle). Live-dissected stage 16 embryos resulting from these crosses were incubated with 10D-AP,
followed by fixation and antibody staining (Fox and Zinn, 2005; Lee et al., 2009) (Figure 1A). In wild-type stage 16 embryos, 10D-AP brightly stains axons in the ventral nerve cord (VNC) and brain (Figure 1C), but body wall staining is weak and has no clear pattern (Figures over 1D and 1E). We searched for insertion lines that produced embryos displaying strong staining of muscle fibers and/or increased staining of cell bodies and axons in the VNC. One line, GE24911, reproducibly conferred strong ectopic staining of muscle fibers and increased VNC staining intensity. This line has an insertion of an EP-like GE element 226 bp 5′ to the transcription start site of sas ( Schonbaum et al., 1992). Analysis of ectopic Sas expression showed that 24B-GAL4 is weaker in the double driver line than as a single driver, suggesting that we might have missed some genes due to insufficient ectopic expression. Accordingly, we repeated the entire screen using a strong pancellular driver, tubulin (tub)-GAL4, and identified nine other candidate binding partners (Figure S1).