Another prominent group, the cells of the vertical system, called VS cells, in general respond most strongly to vertical image motion; downward is their preferred direction and upward is their null

direction. However, precise mapping of the cells’ local preferred directions revealed a spatially nonuniform receptive field; the different preferred directions in different parts of the fly’s visual field resemble an optic flow pattern as might be elicited by the fly during certain flight maneuvers (Krapp and Hengstenberg, 1996 and Krapp et al., 1998). These large and elaborate receptive fields could be shown to result from a combination of direct feed-forward input the tangential cells receive from columnar motion-sensitive elements and lateral synaptic interactions between the various tangential cells within the lobula plate (Borst and Weber, 2011; for review, see Borst et al., 2010). As for

the nature of their retinotopic selleck inhibitor input elements, the lobula plate tangential cells have been subjected to numerous tests investigating whether they conform to the Reichardt model in blow flies, 3-MA mw hover flies, and fruit flies. In these experiments, tangential cells were stimulated by periodic gratings moving at a constant velocity (Haag et al., 2004, Joesch et al., 2008 and Schnell et al., 2010) or with a dynamic velocity profile (Egelhaaf and Reichardt, 1987, Egelhaaf and Borst, 1989, Borst et al., 2003, Reisenman et al., 2003, Borst et al., 2005 and Spavieri et al., 2010). Some

studies investigated the local motion response by restricting the field of view to a small window through which the pattern was shown to the fly (Egelhaaf et al., 1989) or by using intracellular calcium concentration changes as a readout for local activity in the dendrite (Single and Borst, 1998 and Haag et al., 2004). Tangential cells were also stimulated by natural images (Dror et al., 2001) or by apparent motion stimuli consisting of spatially displaced sequences of discrete brightness steps (Egelhaaf and Borst, 1992). All these studies concluded that the Reichardt detector accurately describes no the behavior of these input elements. As an example, the responses of Drosophila HS cells have been measured as a function of pattern contrast ( Figure 2D): Although the response does not rise quadratically as predicted by a perfect multiplication, it clearly increases with increasing pattern contrast, thus ruling out a division of temporal by spatial gradient as specified in the gradient detector. When stimulated by a periodic grating drifting at different velocities, the response of HS cells displays a velocity optimum, as predicted by the Reichardt detector ( Figure 2E, black trace). Furthermore, when the test is repeated with a grating of twice the spatial wavelength, the optimum velocity is doubled ( Figure 2E, gray trace).

, 2008). Thus, while these forebrain areas appear to depend upon the brainstem arousal influence in the intact individual, they apparently can reorganize to support cortical arousal even without input from the brainstem.

One of these forebrain arousal systems is found in the posterior half of the lateral hypothalamus. Just http://www.selleckchem.com/products/wnt-c59-c59.html dorsal and rostral to the histaminergic neurons of the TMN, the lateral hypothalamus contains neurons producing the orexin neuropeptides (orexin-A and -B, also known as hypocretin-1 and -2). Many of the orexin neurons also contain glutamate, and nearly all also contain the neuropeptide dynorphin ( Chou et al., 2001 and Torrealba Enzalutamide price et al., 2003). They send axons to the entire cerebral cortex, as well as to the brainstem and basal forebrain, with particularly intense input to the TMN and the LC ( Peyron et al., 1998). There is also less intense orexin innervation of the intralaminar nuclei of the thalamus as well as the anteroventral thalamic nucleus. There are two known orexin receptors, both of which are G protein coupled receptors with excitatory membrane effects ( Sakurai et al., 1998). Orexin neurons

receive afferents from many components of the ascending arousal system, including the LC, dorsal raphe (DR), and parabrachial nucleus, as well as from cortical (medial prefrontal) and amygdaloid (central nucleus) sources associated with arousal and ventral tegmental sites associated with reward ( Yoshida et al., 2006). They fire predominantly during wakefulness, and fire particularly briskly during active exploration of the environment or during motivated behaviors ( Lee et al., 2005 and Mileykovskiy et al., 2005). Orexin neurons are also driven by low glucose ( Moriguchi et al., 1999) and may

play an important role in motivating foraging behaviors in hungry animals as well as in reward and drug seeking behaviors ( Harris et al., 2005 and Yamanaka et al., 2003). Selective activation of the orexin neurons Amisulpride with a light-sensitive sodium channel awakens mice from sleep, suggesting that the orexin neurons are capable of driving arousal from sleep ( Adamantidis et al., 2007 and Carter et al., 2009). Most importantly, selective destruction of the orexin neurons with a genetically targeted toxin results in the symptoms of narcolepsy ( Hara et al., 2001), which will be discussed in a separate section below. Overall, the orexin neurons are thought to sustain wakefulness and suppress REM sleep. On the other hand, large lesions of the posterior lateral hypothalamus (Gerashchenko et al., 2003, Nauta, 1946, Ranson, 1939 and Swett and Hobson, 1968) produce much more extensive sleepiness than can be explained by elimination of just orexin and histamine transmission.

In the RADIANT study from the UK, sex was coded as a factorial covariate for the analysis presented in the main text. The validity of the p values and the distribution of the estimates were verified using Monte-Carlo (permutation and bootstrap) methods. Below we give the odds ratios

(OR) without LGK-974 research buy sex as a factorial covariate and the ORs in a gender stratified analysis: OR of all RADIANT cases and RADIANT plus WTCCC2 controls, sex not included as covariate: 1.082 (95% C.I. 0.951; 1.231), n = 1636 cases and 7261 controls with a p = 0.274. OR of only male cases and male controls: 1.344 (95% C.I. 1.080; 1.672), n = 485 cases and 3465 controls with a p = 0.00797. OR of only female cases and female controls: 0.959 (95% C.I. 0.816; 1.127), n = 1151 cases, 3781 controls with a p = 0.615. Meta-analyses were conducted using the R library rmeta applying a fixed effect model. In the first meta-analysis, three genetic models were tested, the two opposite carrier models and an allelic model resulting in a number of 2.02 effective tests as estimated from 10,000 permutations. In the second meta-analysis (combining the results of the first meta-analysis with the data from the RADIANT/WTCCC2 sample), only the recessive model for rs1545843 was

tested. The adjustment for the two tests performed in RADIANT/WTCCC2 was done by adjusting the standard error of the estimate accordingly. We used two independent genome-wide SNP/mRNA expression data sets for SNP-eQTL analyses on 12q21.31.

The first data set was find more from premortem human hippocampus of 137 individuals involved in the Epilepsy Surgery Program at Bonn University, Germany. Methods related to the hippocampal eQTL experiment are detailed in the Supplemental Experimental Procedures. The second was the publicly available GENEVAR (GENe Expression VARiation) data set of EPV-transformed lymphocytes from the 210 unrelated HapMap individuals (http://www.sanger.ac.uk/humgen/genevar/) (Stranger et al., 2005 and Stranger et al., 2007). In both data sets, we selected all RefSeq annotated genes (Pruitt first et al., 2005) located within 1.5 megabase on both sides of the genome-wide significant SNP of the GWAS (rs1545843, total sequence of 3 Mb). The five following genes intersect with the defined genomic region (hybridization probes in brackets, see also Table S1): TMTC2 (GI_22749210-S), SLC6A15 (GI_33354280-A, GI_21361692-I, GI_33354280-I), TSPAN19 (GI_37541880-S), LRRIQ1 (hmm2373-S), and ALX1 (GI_5901917-S). For the GENEVAR data set a residual expression variable for each probe was built by regression analysis to correct for ethnicity. We tested an allelic and both alternative recessive-dominant genetic models for rs1545843 and rs1031681 for each of the probes (n = 7) by performing ANOVA under 106 permutations using the WG-Permer software. p values were corrected for multiple comparisons by the Bonferroni procedure.

6 ± 0.8, p < 0.0001 paired Student's t test; HgfpH 3.6 ± 0.7, p < 0.05 paired Student's t test; Figure 2C). Similar results were observed when reporter expression

was compared in all DD and VD neurons (DD/VD fluorescence ratios: HgfpC 5.6 ± 0.5, p < 0.0001 paired Student's t test; HgfpH 2.6 ± 0.4, p < 0.005 paired Student's t test; Figures 2A and 2B and Figures S2B and S2D). selleckchem These results indicate that the hbl-1 promoter is expressed at significantly higher levels in DD neurons than in VD neurons. The decreased hbl-1 reporter expression in VD neurons could result from UNC-55 mediated repression of the hbl-1 promoter. To test this possibility, we analyzed expression of the HgfpC reporter in unc-55 mutants. HgfpC expression in VD neurons was significantly increased in unc-55 mutants (197% wild-type levels, p < 0.001 Student's t test), indicating increased transcription of the hbl-1 promoter in unc-55 mutant VD neurons ( Figure 2D and Figures S2B–S2D). The magnitude of the increased HgfpC expression differed in individual VD neurons. For VD10, HgfpC

expression in unc-55 mutants rose to the same level observed in DD5 neurons ( Figure 2D); however, in most cases, HgfpC expression in unc-55 mutant VD neurons remained significantly lower than that observed in DD neurons (DD/VD fluorescence ratio in unc-55: HgfpC 2.3 ± 0.4, p < 0.001 Student's t test; Figures S2C GDC-0449 supplier and S2D). By contrast, HgfpC expression in DDs did not increase in unc-55 mutants and instead was modestly decreased ( Figure 2D and Figure S2D). This is unlikely to be a direct effect of UNC-55 on the hbl-1 promoter because unc-55 is not expressed in DD neurons

( Zhou and Walthall, 1998). Taken together, these data support the idea that UNC-55 inhibits expression of the hbl-1 promoter in VD neurons and that hbl-1 expression in D neurons is likely regulated by additional factors beyond UNC-55. In Drosophila, the UNC-55 ortholog (Sevenup) represses Hunchback (Hb) transcription ( Kanai et al., 2005 and Mettler et al., 2006). As in Drosophila, the C. elegans hbl-1 promoter contains four predicted UNC-55 binding sites, suggesting the hbl-1 could be a direct target for UNC-55 repression. To test this idea, we mutated the UNC-55 binding sites in the Sitaxentan hbl-1 promoter, and assayed its expression pattern. The mutant hbl-1 promoter (HmutgfpC) had a significantly reduced DD5/VD10 expression ratio (HgfpC 6.6 ± 0.8; HmutgfpC 2.7 ± 0.3, p < 0.0001 Student’s t test) ( Figure 2E), which was not significantly different from the ratio observed for the wild-type reporter (HgfpC) in unc-55 mutants (1.8 ± 0.3, p = 0.17, Student’s t test) ( Figure 2F). Thus, the UNC-55 binding sites are required for differential expression of the hbl-1 promoter in VD and DD neurons. If UNC-55 repression of hbl-1 prevents VD remodeling, we would expect that mutations reducing hbl-1 activity would diminish ectopic remodeling of VD synapses in unc-55 mutants.

The low probability of neurotransmitter release renders single-spike transmission unreliable, which may serve to provide a large dynamic range for plasticity or to maximize the brain information storage capacity under resource constraints (Varshney et al., 2006). Neurons can use two strategies to overcome the unreliability of single-spike transmission. They can either simultaneously activate multiple synapses connecting to the same target via isolated spikes or repeatedly activate a single synapse via bursts of spikes (Lisman, 1997). Each of these strategies incurs a tradeoff. The use of multiple synapses allows information

to be transmitted by a single spike, thus ensuring high speed, temporal precision, and strength but at the cost of a reduced capacity for storing and processing information

(Varshney et al., 2006). Some synapses Ceritinib in sensory transduction or motor control pathways choose this strategy, for example, the calyx of Held synapse in the auditory pathway, which forms more than 500 release sites on its target neuron (Meyer et al., 2001) or climbing fibers in the cerebellum, which form multiple synapses on a single Purkinje cell (Silver et al., AP24534 mw 1998). Conversely, the use of burst-mediated transmission requires only one or a few synapses for high-fidelity transmission but reduces the temporal resolution of transmission, as observed, for example, in inhibitory interneurons (Sheffield et al., 2011). Therefore, this mode of firing may be better suited for neurons involved in the storage of large amounts of information. Bursts may also play roles in the organization of neuronal assemblies and dendritic PAK6 local integration (Izhikevich et al., 2003 and Polsky et al., 2009). Although firing of isolated spikes and bursts of spikes have long been recognized as the two principal modes of information coding, their relative importance in a particular neuronal circuit has been difficult to test experimentally, especially in behaving animals, because no approach to selectively shut down

one or the other mode of synaptic transmission was available. Here, we show that synaptic transmission triggered by isolated spikes can be selectively ablated by using knockdown (KD) of synaptotagmin-1 (Syt1), the major Ca2+ sensor for synchronous neurotransmitter release (Geppert et al., 1994). However, as in Syt1 knockout mice (Maximov and Südhof, 2005), the Syt1 KD does not abolish release in response to bursts of spikes. Instead, the Syt1 KD shifts the timing of release induced by a high-frequency action-potential train into a delayed, nonphysiological mode, because the massive influx of Ca2+ into nerve terminals induced by a high-frequency action-potential train activates asynchronous release that is normally suppressed by the presence of Syt1 (Maximov and Südhof, 2005).

In this study, we

found that neurons in both the caudate nucleus and ventral striatum encoded temporally discounted values. However, neurons in the ventral striatum tended to represent the sum of the temporally discounted values for the two targets, whereas those in the caudate nucleus additionally encoded the signals necessary for selecting the action with the maximum temporally discounted value, namely, the relative selleck chemicals difference in the temporally discounted values of the two alternative rewards. Therefore, the primate dorsal striatum might play a more important role in decision making for delayed rewards. Two monkeys (H and J) were trained to selleck products perform an intertemporal choice task, in which they chose between two different amounts of juice that is either available immediately or delayed (Kim et al., 2008 and Hwang et al., 2009).

The magnitude and delay of each reward was indicated by the color of the target and the number of small yellow dots around it (Figure 1A, top; see Experimental Procedures). Both animals chose the small reward more often as the delay for the small and large reward decreased and increased, respectively, indicating that they integrated both reward magnitude and delay to determine their choice. The choice behavior during this task was modeled using exponential and hyperbolic discount functions. We

found that among 61 and 116 sessions tested for monkeys H and J, respectively, the hyperbolic discount function provided the better fit in 55.7% and 98.3% of the sessions (Figure 1B). The median value of k parameter was 0.18 and 0.25 s−1 for monkey H and J, corresponding to the half-life (1/k) of 5.6 and 4.0 s, respectively. Single-neuron activity was recorded from 93 neurons in the caudate nucleus (CD; 32 from monkey H, 61 from monkey very J) and 90 neurons in the ventral striatum (VS; 33 from monkey H, 57 from monkey J) during the intertemporal choice task (Figure 1C). In addition, each of these neurons was also tested during the control task, in which the animal was required to shift its gaze according to the color of the central fixation target (Figure 1A, bottom). Although the visual stimuli were similar for the two tasks, the reward delay and magnitude were fixed for all targets during the control task, which made it possible to distinguish between the activity changes related to the temporally discounted values and those related to visual features of the computer display (see below). To analyze the neural activity during the intertemporal choice task, we estimated the temporally discounted values for both targets in each trial using the discount function estimated from the animal’s behavior (see Experimental Procedures).

, 2000). In the adult SVZ, the vasculature PLX3397 comprises an extensive network of planar interconnected blood vessels (Shen et al., 2008 and Tavazoie et al., 2008). Contacts between adult SVZ precursors and blood vessels are unusually permeable and frequently devoid of astrocyte and pericyte interferences, suggesting that blood-derived cues are gaining direct access to adult neural precursors and their progeny. The vasculature also provides the substrate for new neuron migration after injury in the adult striatum (Kojima et al., 2010). With endfeet surrounding

blood vessels, astrocytes form gap junctions and are closely associated with the vasculature and its basal lamina in the adult SVZ and SGZ. They may serve as an interface to modulate influences

of endothelial and circulation-derived factors as well as the availability of cytokines and growth factors in the basal lamina. In addition, astrocytes derived from neurogenic hippocampus and SVZ, but not from nonneurogenic spinal cord, promote proliferation and neuronal fate commitment of multipotent adult neural stem cells in culture (Lim and Alvarez-Buylla, 1999 and Song et al., 2002). Astrocytes express a number of secreted and membrane-attached factors both in vitro and in vivo that are known to regulate proliferation and fate specification of adult neural precursors as well as neuronal migration, maturation, and synapse formation (Barkho et al., 2006). In the adult SVZ, astrocytes express Robo receptors and regulate the rapid migration of Slit1-expressing neuroblasts through the RMS (Kaneko et al., 2010). Adult SVZ astrocytes also mTOR inhibitor review appear to release glutamate to regulate the survival of neuroblasts (Platel et al., 2010). Unique to the adult SVZ, ependymal cells lining the ventricular wall are in close association with neural precursors and their progeny, acting like a shield to protect the neurogenic niche. Ependymal cells actively regulate neuronal fate specification of adult neural precursors through before release of Noggin (Lim et al., 2000). Beating of the cilia of ependymal cells appears

to set up concentration gradients of guidance molecules to direct migration of neuroblasts (Sawamoto et al., 2006). Microglia also actively regulate adult neurogenesis. Under basal conditions, apoptotic corpses of newly generated neurons are rapidly phagocytosed from the niche by unactivated microglia in the adult SGZ (Sierra et al., 2010). Under inflammatory conditions, reactivated microglia can have both beneficial and detrimental effects on different aspects of adult neurogenesis, depending on the balance between secreted molecules with pro- and anti-inflammatory action (reviewed by Ekdahl et al., 2009). In one study, the activation of microglia and recruitment of T cells were suggested to be required for enriched environment-induced SGZ neurogenesis (Ziv et al., 2006).

For example, at a luminance coherence of 100%, all dots falling within the word form were black, and all dots outside the word form were white. For a luminance coherence of 50%, half the dots within the word form would be set to black (and half the dots outside the word form to white), while the rest of the dots (noise dots) Trichostatin A nmr were set randomly to black or white. Similarly, at 0% luminance coherence, all dots were randomly set to black or white, and thus no information about the original

word form was present in the image. The values of luminance coherence used in this study were 0%, 15%, 30%, and 45%. The dots moved either left or right over successive frames (dot life = 4 frames, frame rate 60 Hz). For luminance-dot words, the motion of each dot was set randomly to left or right (0% motion coherence). The motion direction of each dot remained unchanged for 4 frames, at which point this dot disappeared and a new dot appeared in a random location to replace it. For motion-dot words, word form was encoded by the direction of dot motion. The procedure for making these stimuli was identical to that used for making

luminance-dot words, except that visibility was controlled by motion coherence, Lenvatinib concentration and dot luminance was randomly set to black or white. Signal dots moved to the right if they fell within the word form and to the left if they fell outside it (dot life = 4 frames). All other Tryptophan synthase dots were noise dots and were therefore randomly assigned a leftward or rightward direction. Motion coherence, like luminance coherence, controlled the percentage of signal dots. The values of motion coherence were 0%, 50%, 75%, and 100%. The actual values of luminance and motion coherence are not meaningful in that their precise relationship to visibility depends critically on many other stimulus parameters, such as dot size, stimulus size, and dot density. Therefore we chose values that produced approximately similar visibility levels, from complete noise to fully visible, based on initial psychophysical piloting

with our stimulus parameters. This stimulus type was constructed identically to the motion-dot and luminance-dot stimulus types. Four conditions were chosen by adjusting both luminance and motion coherence of the stimuli, as described above. The luminance and motion coherence values matched the middle two coherence values for the luminance-dot and motion-dot stimuli (thus producing 2 × 2 = 4 total conditions). Examples illustrating the two dynamic stimuli and the line contour stimulus are included in the Figure S2 and Movies S1. Related to Figure 2: Example Stimuli and Movie S2. Related to Figure 2: Example Stimuli. To examine the necessity of area hMT+ for reading words of different stimulus features, we used transcranial magnetic stimulation (TMS) and targeted the center of the functional hMT+ ROI defined for each individual subject.

However, no NMDAR-LTD could be observed in the cells transfected with the shRNAs (Figures 5G and 5H), whereas NMDAR-LTD was reliably induced in interleaved experiments in neurons transfected with control shRNA (Figure 3H). With both shRNAs against STAT3 there was a small decrease selleck kinase inhibitor in the synaptic response following the LTD stimulus

protocol but this was similar for both the test and control inputs, and significantly smaller than for control LTD. When all these data are considered together it strongly suggests that STAT3 is the isoform involved in NMDAR-LTD. Since, when activated, STAT3 translocates to the nucleus, we wanted to see if this activation and translocation also occurs during NMDAR-LTD. In cultured hippocampal neurons under control conditions, STAT3 immunoreactivity was fairly evenly distributed throughout the neuron, including the nucleus (Figure 6A). NMDA treatment (20 μM,

10 min) resulted in nuclear translocation and activation of STAT3 (Figure 6A). Maximal nuclear accumulation was observed immediately following NMDAR stimulation and the effect persisted for between 1 and 2 hr (Figures 6A and 6B). There was a corresponding activation of nuclear STAT3, as assessed by the phosphorylation of Tyr 705 (P-STAT3), which also lasted for between 1 and 2 hr (Figures 6A and 6B). Consistent with the activation of STAT3 being mediated by JAK2, treatment of cultures with AG490 prevented both the translocation of STAT3 and activation of nuclear STAT3 (Figure 6C). To investigate ALK inhibitor whether STAT3 is also activated by LFS in hippocampal slices, we analyzed the levels of STAT3 and P-STAT3 in the CA1 region of hippocampal slices by western blotting. For these experiments, we microdissected both stratum

radiatum, which is enriched in CA1 dendrites, and stratum pyramidale, which is correspondingly enriched in CA1 cell soma (Figure 6D). We prepared a nuclear fraction from the microdissected cell soma preparation and examined the expression of P-STAT3 relative to total STAT3. LFS resulted in a pronounced L-NAME HCl activation of nuclear STAT3 (199% ± 23%, n = 14, Figures 6D and 6F), which was absent if LFS was delivered in the presence of AP5 (94% ± 8%, n = 10), okadaic acid (87% ± 17%, n = 5) or cyclosporine A (136% ± 46%, n = 5; Figures 6E and 6F). Interestingly, LFS also resulted in activation of dendritic STAT3 (135% ± 10%, n = 14; Figures 6D and 6F) and this effect was also dependent on the synaptic activation of NMDARs (110% ± 11% in presence of AP5, n = 10; Figures 6E and 6F). These results are consistent with the immunocytochemistry (Figures 6A and 6B) in cultured neurons and extend them by showing the dependence of nuclear STAT3 activation on the PP1/PP2B protein phosphatase cascade.

While reducing CaCC with 100 μM NFA enhanced EPSP summation under physiological conditions with 10 mM [Cl−]in VE-822 concentration (Figure 6D, left panel), 100 μM NFA reduced EPSP summation in 130 mM [Cl−]in (Figure 6D, middle panel). NFA had no effect on EPSP summation when BAPTA was included with 10 mM [Cl−]in to chelate Ca2+ (Figure 6D, right

panel). These controls reinforce the conclusion that CaCC modulates synaptic input integration in hippocampal neurons. Lastly, to test whether CaCCs contribute to EPSP-spike coupling, we applied five nerve stimuli at 40 Hz. Using nerve stimulation that generated EPSPs too small to reach threshold for spike initiation even with temporal summation in control conditions (Figure 6E, control, black), we found that reducing CaCC activity with 100 μM NFA enhanced EPSP-spike coupling and helped neurons to

reach threshold for spike firing (Figure 6E, red). Sirolimus cost Whereas under physiological conditions with 10 mM [Cl−]in (Figure 6F, left panel), reducing CaCC with 100 μM NFA enhanced EPSP-spike coupling, in 130 mM [Cl−]in (Figure 6F, middle panel) 100 μM NFA dampened EPSP-spike coupling. NFA had no effect on EPSP-spike coupling when BAPTA was included with 10 mM [Cl−]in to chelate Ca2+ (Figure 6F, right panel). Thus, CaCC modulates EPSP-spike coupling in a Ca2+-dependent manner (Table 1) by raising the threshold for spike generation by EPSP under physiological conditions, whereas with elevated internal Cl− CaCC acts to reduce the threshold instead (Table 1). Taken together, these studies show that CaCC normally acts as an inhibitory brake on action potential duration, EPSP size, EPSP summation as well as EPSP-spike coupling (Table 1). As illustrated in control studies with elevated internal Cl− (Table 1), raising internal Cl− concentration during neuronal activity or dysfunction could cause

CaCC to provide positive feedback and enhance excitation. This study documents the existence and physiological functions of Ca2+-activated Cl− channels (CaCCs) in Methisazone hippocampal pyramidal neurons. In this study, we show that hippocampal pyramidal neurons have functional CaCCs, and their function depends on TMEM16B but not TMEM16A. We have further examined the physiological roles of CaCCs, as summarized below. The evidence for CaCC in hippocampal pyramidal neurons includes: (1) activation of voltage-gated Ca2+ channels induces a tail current that reverses at ECl (Figure 1). (2) This Cl− current is activated by Ca2+, and its size varies with the amount of Ca2+ influx (Figure 2). (3) The tail current is blocked by two structurally distinct CaCC blockers, NFA and NPPB (Figure 3A). (4) This tail current is greatly reduced by shRNA knockdown of TMEM16B, which encodes a CaCC (Figures 4C and 4D).