Cells were cotransfected with RGEF-1b and either FLAG-tagged LET-60 or RAP-1 transgenes. After incubation with 50 nM PMA or vehicle for 15 min, cells were lysed and amounts of LET-60-GTP or RAP-1-GTP were assayed by western immunoblot analysis. RGEF-1b promoted modest accumulation of LET-60-GTP in untreated cells (Figure 1A, lane 3).

In contrast, RGEF-1b activity increased ∼6-fold when cells were incubated with PMA (Figure 1A, lane 4). If RGEF-1b has a functional C1 domain, it will be regulated by endogenous DAG. Cells were transfected with bombesin receptor, RGEF-1b and FLAG-LET-60 transgenes. Bombesin receptor, which has seven transmembrane domains and couples with heterotrimeric Gq protein, promotes DAG production C59 wnt order (Feng et al., 2007). When bombesin peptide

binds, the receptor elicits PLCβ activation via Gαq-GTP. PLCβ generates DAG and IP3 by cleaving PI4,5P2 in membranes. Incubation of cells with bombesin increased RGEF-1b-mediated LET-60 activation ∼4-fold (Figure 1B, lanes 3 and 4). Stimulation by both bombesin and PMA (a DAG surrogate) suggests that DAG is a major regulator of RGEF-1b catalytic activity. Modest basal and PMA-stimulated accumulation of RAP-1-GTP was evident in HEK293 cells lacking ISRIB datasheet RGEF-1b because of endogenous GEFs (Figure 1C, lanes 1 and 2). Expression of RGEF-1b elicited increased accumulation of RAP-1-GTP in the absence of stimuli (Figure 1C, lane 3). Moreover, PMA further enhanced RGEF-1b catalyzed loading of GTP onto RAP-1 (Figure 1C, lane 4). Thus, LET-60 and RAP-1 are RGEF-1b substrates. A fragment of genomic DNA (2670 bp) that precedes exon 1 of the rgef-1 gene was amplified by PCR. This DNA, which contains promoter-enhancer elements, was inserted upstream from a green fluorescent protein (GFP) reporter gene in a C. elegans expression plasmid (pPD 95.77). Animals stably expressing the rgef-1::GFP transgene were generated by microinjection. Cells producing GFP were identified by fluorescence microscopy and reference to the WORMATLAS anatomy database. rgef-1 promoter activity was evident in a high proportion of neurons ( Figures 2A and 2C) in four independently Sodium butyrate isolated

strains. GFP was not detected in nonneuronal cells. Terminal divisions and differentiation of neurons were completed before rgef-1 promoter activity was switched on during late embryonic development ( Figure 2E). Panneuronal GFP fluorescence was sustained from the end of embryogenesis (hatching) through adulthood. We characterized a gene deletion mutant (rgef-1(ok675)) acquired from the C. elegans Knockout Consortium. Gene fragments were amplified by PCR ( Figure S2). DNA sequencing revealed that nucleotides 1493–2594 were deleted from the rgef-1 gene. This eliminated exons 5–7 and part of exon 8 ( Figures S1A and S2), which encode the RGEF-1b catalytic domain. Splicing of exon 4 to exon 9 would yield a mutant protein lacking GTP exchange activity. Thus, the disrupted rgef-1 gene is a null mutant.

These enzymes can be used to induce a double-strand break in a specific targeted location in the human genome, therefore allowing for increase likelihood of homologous recombination VX-809 cell line with an additionally provided exogenous DNA contruct (Klug, 2010). The fidelity of this system relies on the specificity provided by the zinc finger DNA binding domains. Atlhough the selection and validation of ZFNs can be a costly or laborious process with significant lab expertise required (Doyon et al., 2008, Isalan et al., 2001, Maeder et al., 2008 and Pearson, 2008), the development of rapid, low-cost, and user-friendly in silico selection alternatives for designing

functional ZFNs has recently been demonstrated (Sander et al., 2011), which may improve the overall utility of ZFN techonology for gene-targeting experiments. In the context of hiPS cell disease modeling, the use of ZFN-mediated targeting to correct a genetic defect in a patient-specific iPS cell line and in turn rescue a disease-associated phenotype, remains to be demonstrated. Given inherent genetic heterogenity between individuals, the issue of what constitutes the GPCR & G Protein inhibitor most appropriate control iPS cell line for any given patient-derived iPS cell line remains poorly defined. For single-gene defects, future use of gene-targeted approaches described above to generate isogenic control lines will undoubtedly

be powerful tools. In addition, as several important neurological disorders are caused by gene defects on the X chromosome, iPS cell lines from females expressing either the mutant or normal allele based on which X chromosome has inactivated could theoretically provide useful phenotypic comparisons (see discussion on Rett Syndrome). However, for this approach to be successful, the dynamics

of X chromosome inactivation in cultured human pluripotent stem cells needs to be more extensively studied. Apart from these approaches, the issue of Metalloexopeptidase what constitutes the best control line is currently unresolved. For monogenetic disorders, it will be necessary to show that the healthy controls do not harbor the disease-associated genotype. For example, use of cells from a healthy sibling who has tested negative for the disease-causing gene mutation, when available, would constitute a desirable control. For late-onset neurodegenerative disorders that are relatively common, the appropriate controls should be from individuals who are not only “neurologically healthy” but also advanced enough in age to minimize the possiblity of selecting a control that is at risk of developing the disease. In this regard, collaborations with neurologists and clinical follow-up of these patients will be important. Comparison of disease-specific iPS cell lines to well-characterized hES cell lines may be useful (Boulting et al., 2011).

Consistent with the observation

that Atoh1 is essential for the formation of RL descendants Epacadostat ic50 ( Machold and Fishell, 2005; Wang et al., 2005), RL-derived Atoh1 populations in the ventral medulla, including the lateral reticular nucleus (LRt) and spinal trigeminal neurons (Sp5I), were virtually abolished in the Atoh1 null brainstem at E18.5 ( Figure 1, compare C to B). In contrast, Atoh1 null mice still retain the RL-independent RTN neurons, but the somas cluster at the dorsal surface of nVII, likely as a result of a migration defect (white arrowheads) ( Figures 1B and 1C). Moreover, the closely localized nVII neurons, which do not express Atoh1, show normal marker expression and localization ( Figures S1A and S1B available online), suggesting their development is Atoh1 independent. During embryonic development, the RTN neurons migrate radially to assume their final location around the nVII, with the majority of them lining the ventral medullar surface (Dubreuil et al., 2009; Rose et al., 2009b). In Atoh1 null mice, the mislocalized RTN neurons retain expression of lineage markers such as Phox2b and ladybird homeobox homolog 1 (Lbx1), similar to WT mice ( Figures 1D and 1E), indicating that their lineage identities are unchanged. This defect is different from the CCHS mouse model, in which these neurons do not form ( Dubreuil et al., 2008). Rapamycin molecular weight We then stained for myristoylated

GFP to ask whether loss of Atoh1 affects neuronal connectivity of lower brainstem circuitry. In oxyclozanide the preBötC region (orange dotted circled neurons marked by somatostatin, Sst) of the E18.5 WT brainstem ( Figure 1F), we detected neuronal processes extending from both rostral (white open arrowheads) and caudal (white arrowheads) Atoh1 populations. The rostral neuronal bundles correspond to the pontine Atoh1 respiratory populations and the RTN neurons, while the caudal processes belong predominantly to the LRt neurons ( Abbott et al., 2009; Rose et al., 2009a, 2009b). This early connectivity is consistent with connectivity in adult

rodents and functional connectivity occurring prior to the onset of inspiratory behaviors in utero ( Feldman and Del Negro, 2006). In the Atoh1 null brain, the preBötC received little to no Atoh1-dependent rostral and caudal inputs ( Figure 1G). Notably, neurites of the mislocalized RTN neurons accumulate at the dorsal side of nVII and do not extend to the preBötC. This suggests that Atoh1 null RTN neurons not only mislocalize but also lack direct targeting to the primary breathing center. In an effort to identify the Atoh1 subpopulations critical for neonatal survival, we applied conditional knockout strategies. We have previously shown that removal of Atoh1 using a HoxB1Cre allele that covers all tissues caudal to the rhombomere 3/4 boundary results in 50% neonatal lethality ( Maricich et al., 2009).

Five new probes were engineered with super KU-55933 mouse ecliptic pHluorin A227D relocated closer to the S4 domain of the CiVS, after amino acids Q239, M240, K241, A242, or S243 (Figure S1B). Each of the five derivatives of ArcLight resulted in a further increase of the response magnitude (∼35% versus ∼18% ΔF/F) to a 100mV depolarization step (Figure 2C). Thus the large improvement of signal size seen with this mutation is not limited to a specific location along the linker segment; an even greater increases in signal size was achieved by moving the FP closer to the S4 domain. Optical methods offer the promise of less invasive, better targeted, and greater multisite monitoring of neuronal activities compared

to traditional electrode-based methods. A number of Erastin FP-based, self-contained probes of membrane potential have been described (Siegel and Isacoff, 1997; Sakai et al., 2001a; Ataka and Pieribone, 2002; Baker et al., 2007; Dimitrov et al., 2007; Lundby et al., 2008; Tsutsui et al., 2008).

While FP-based voltage sensors may perform well in cell lines (i.e., HEK293, PC12, etc.), it has been challenging in many cases to transfer probes into neurons and still observe detectable responses (Akemann et al., 2010). All of the FP-based probes cited above suffered from one or more problems, including low intensity of probe fluorescence in neurons, small response magnitudes, slow kinetics of the fluorescence response, and poor membrane versus intracellular localization (Perron et al., 2009). To date none of these have Oxalosuccinic acid convincingly demonstrated detection of individual action potentials and postsynaptic potentials in neurons. When expressed in neurons, the signal-to-noise ratio for action potential detection using these probes has been poor (Baker et al., 2007; Perron et al.,

2009). Expression of ArcLight and its derivatives in cultured mouse hippocampal neurons produced brightly fluorescent cells (Figure 3, Figure 4 and Figure 5; Figure S4A) with expression both in the soma and dendrites (Figure S4A). In dendrites it appears largely membrane localized (Figure S4A). The probe did not appear to dramatically alter neuronal excitability as electrical recordings of spontaneous action potentials in nontransfected, mock-transfected, and ArcLight-transfected neurons had widths and amplitudes that were not significantly different (Figures S4B and S4C). The probe also did not appear to cause excessive phototoxicity as spontaneous action potentials of similar properties could be observed following at least 4 min (longest period tested) of excitation (Figure S4D). In spite of the relatively slow response of the probe in HEK293 cells (fast τ ∼10 ms), we could optically detect spontaneous (Figure 3A) and evoked action potentials (Figure 3C) in neurons expressing the ArcLight probes. The response appeared as a −1 to −5% ΔF/F (−3.2% ± 2.2%, n = 20 cells) change in the fluorescence intensity.

, 1998 and Yang et al., 2009). Similar approaches using morpholinos in Xenopus and zebrafish embryos have also been reported (for example, Wilson and Key, 2006, Kee et al., 2008 and Rikin et al., 2010). An effective artificial miRNA against Shh

has been described (miShh; Das et al., 2006), and we have shown that, as expected, it induces both pre- and postcrossing axon guidance errors when expressed in the floorplate at HH17 or earlier (Wilson and Stoeckli, 2011). Here, we coelectroporated Math1-EGFPF-mi7GPC1 and Hox-EBFP2-miShh constructs at low concentrations Selleckchem AZD2281 to reduce GPC1 in dI1 neurons and Shh in the floorplate ( Figures 3A and 3A′). Under these conditions, the single knockdown of each gene did not significantly affect axon guidance compared to control embryos expressing only mi1Luc. However, the concomitant knockdown of axonally expressed GPC1 and floorplate-derived Shh led to increased defects in the guidance of postcrossing axons ( Figures 3B–3F; Table S2). Interestingly, we did not see any increase in ipsilateral errors ( Table S2), suggesting that GPC1 does not influence the attractive activity of Shh in precrossing axons. This finding is in line with results from a separate

series of experiments in which we interfered with GPC1 expression at earlier stages (HH12–HH14; at least 15 hr before the commissural neurons begin to project axons) and saw no additional effects on precrossing axons ( Table S3). In particular, NVP-AUY922 purchase we did not find axons that failed to reach the floorplate, as would be expected if GPC1 and Shh would cooperate in the attraction of precrossing axons. Taken together, our results suggest that GPC1 and Shh collaborate specifically during postcrossing commissural axon guidance. To strengthen this interpretation, we also performed experiments in which we knocked down Shh together with Contactin2 (Cntn2), a gene that acts in

a different pathway to regulate midline crossing. We have previously shown that axonally expressed Cntn2 interacts with midline-derived NrCAM to make axons enter the floorplate (Stoeckli and Landmesser, 1995 and Wilson and Stoeckli, 2011). In postcrossing axons, Cntn2 interacts with NgCAM to regulate axon fasciculation (Stoeckli and Landmesser, 1995). In our found combinatorial knockdown experiments, the simultaneous knockdown of genes involved in parallel pathways should not cause a significant aggravation of the single gene manipulations. In line with this reasoning, we saw no exacerbation of either precrossing or postcrossing axon guidance phenotypes after combinatorial knockdown of Shh and Cntn2 (Figure 3F; Table S2). These findings strongly support our conclusion that GPC1 and Shh act in the same molecular pathway to regulate postcrossing commissural axon guidance. Next, we confirmed that GPC1 can directly bind Shh by performing coimmunoprecipitations.

An attractive explanation for the impairment of long-term contextual memory after strong training in Paip2a−/− mice is excessive activity-induced translation in the absence of PAIP2A. It is conceivable that partial reduction of PAIP2A, as in Paip2a+/− mice, might have a smaller effect on translation and thus lead to a salubrious effect on memory.

Reduction in the PAIP2A protein levels in Paip2a+/− mice was confirmed by western blotting ( Figure 3A). It is striking that, while similar freezing was observed 1 hr after strong contextual training, it was enhanced 24 hr after training in Paip2a+/− relative to WT mice ( Figures 3B and 3C). These data are consistent with the idea that complete removal of PAIP2A might cause memory impairment via excessive translation in response to strong training. In accordance with these results, L-LTP elicited by TBS was not impaired in Paip2a+/− relative to WT hippocampal 3-MA solubility dmso slices ( Figure 3D). Because adult neurogenesis contributes to fear memory extinction (Pan et al., 2012), which is impaired in Paip2a−/− mice, we examined neurogenesis in WT, Paip2a−/−, and Paip2a+/− mice.

Progenitor cell proliferation within the subgranular zone of the dentate gyrus was assessed using systemic injection of BrdU followed by immunostaining or by staining for Ki-67, a marker of proliferating progenitor cells. It is surprising that the number of BrdU- and Ki-67-positive cells was reduced in Paip2a−/− but not in Paip2a+/− mice as compared to WT mice ( Figure S4A), suggesting that impaired memory MK 8776 extinction in Paip2a−/− GBA3 mice might result from reduced adult neurogenesis.

We also examined the memory phenotype of Paip2b−/− mice, although PAIP2B expression in the brain is lower than PAIP2A ( Berlanga et al., 2006). No differences were found in contextual fear conditioning task between Paip2b−/− mice and their WT littermates 1 hr and 24 hr after training ( Figures S4B and S4C, respectively), suggesting that PAIP2B is not involved in translational regulation of learning and memory. Next, it was pertinent to determine whether PAIP2A is controlled in an activity-dependent manner. No phosphorylation of PAIP2A has been reported. However, PAIP2A levels are homeostatically controlled by proteasome-mediated degradation upon PABP depletion in cell cultures (Yoshida et al., 2006). Therefore, cultured neurons were depolarized with KCl for 5 min to study the effect on PAIP2A levels. PAIP2A protein levels decreased to 69.6% ± 3.3% of baseline 1 min after KCl-induced depolarization and were further reduced to 59.3% ± 4.0% after 10 min. PAIP2A levels returned to normal after 30 min (Figure 4A). Similarly, activation of NMDA receptors with NMDA resulted in the reduction of PAIP2A to 71.8% ± 2.2% of prestimulation levels (Figure 4B). We reasoned that the rapid downregulation of PAIP2A is mediated by proteolytic activity.

For instance, fast-spiking interneurons and adapting interneurons respond to synaptic 3-MA research buy input in fundamentally different ways that strongly shape how these signals are processed in the cortex (Yoshimura and Callaway, 2005). The connectivity of cells within neuronal circuits also influences processing, as with the magnocellular and parvocellular

pathways in the lateral geniculate nucleus of the thalamus, which form separate, parallel streams of visual information that project to segregated areas of visual cortex (Livingstone and Hubel, 1988). Neuromodulation also strongly influences the behavior of distinct cell types. For example, in the basal ganglia, two populations of medium spiny neurons that are defined by their expression of the D1 or D2 dopamine receptor form the direct and indirect pathways, which facilitate and inhibit movement, respectively (Surmeier et al., 2007). Thus, investigation of the morphology, electrophysiology, circuitry, and modulation of individual neurons can identify the different cell types within neuronal circuits and elucidate their distinct roles in processing

information in the PFI-2 supplier brain. The hippocampus is the cradle of cognition—a brain structure critically involved in the formation, organization, and retrieval of new memories. The principal cell type in this region is the excitatory pyramidal neuron—one of the most-studied cells in the mammalian brain—which integrates spatial, contextual, and emotional information and transmits all hippocampal output to various targets throughout the brain. Pyramidal cells in the CA1 and subiculum regions convey this output by firing action potentials either individually or in high-frequency bursts. These distinct firing patterns are functionally important, as bursts may serve to increase the reliability of synaptic communication by increasing the probability of evoking a postsynaptic spike

(Lisman, 1997; Williams and Stuart, 1999) and are involved in the induction of plasticity and the development of place fields (Epsztein et al., Carnitine palmitoyltransferase II 2011; Golding et al., 2002). Indeed, information processing via bursts has been shown to play a key role in the formation of hippocampus-dependent memories (Xu et al., 2012). Despite the functional importance of these different firing patterns, it is not known whether the observed heterogeneity in hippocampal pyramidal cell firing patterns reflects the existence of multiple cell types or a single cell type with variable excitability (Greene and Totterdell, 1997; Jarsky et al., 2008; Staff et al., 2000; van Welie et al., 2006). A single cell type would suggest that all pyramidal cells process information similarly, whereas the existence of multiple stable cell types would allow for specialization of these principal cells in hippocampal function.

Runners who CRFS or CRFS when both barefoot and shod have been studied previously. 5, 9, 14, 16 and 17 However, almost half of the runners in the current study shifted their running style between an RFS when shod and an FFS when barefoot. 12 Within a given group or footwear condition, an increase in speed increases both stride length and stride frequency (Table 1).11, 15 and 20 Barefoot runners generally run with shorter stride lengths and higher stride frequencies and

are more likely to FFS than shod runners (Fig. 3).3, 11, 15, 16 and 20 Shorter stride lengths attenuate the shock wave caused by the heel strike at initial contact2 and may also reduce decelerations that occur within running strides, due to more vertical ground reaction forces.26 Interestingly, CFFS and CRFS runners

used similar stride lengths and frequencies at a given speed and footwear condition (Fig. 3). Shod shifters, however, Linsitinib cost use longer Talazoparib datasheet stride lengths and higher stride frequencies and duty cycles than all other groups (Fig. 3). Runners who change their running style also modulate their stride length and stride frequency. Notably, runners with consistent styles, whether FFS or RFS, have stride lengths, stride frequencies and duty cycles similar to each other across groups. The similar stride lengths, frequencies, and duty cycles between CFFS and CRFS runners may relate more to training level than foot strike pattern. Sometimes, training shortens stride lengths27 and 28 but elite Rolziracetam training lengthens stride lengths.29 In our subjects, even though the level of training and mileage did not differ between the three groups, these effects may mask differences in stride length. When training level is controlled (e.g., in the shifters), FFS barefoot runners shorten their stride lengths compared to the RFS shod runners (Fig. 3).11, 16 and 20 Only the shod shifters ran with longer stride lengths (Fig. 3). These shod runners may be using the cushioning of the shoe to attenuate the

increased shock experienced through the leg and decrease energy absorption when running with longer stride lengths.2 Shorter strides during FFS running also correlate with more vertical landing angles (less overstride; Fig. 4).3 FFS runners land with their shank more vertical (2°) compared to RFS runners (8°). Barefoot RFS runners also land with a more vertical shank compared to shod RFS runners.16 This vertical landing angle in FFS runners likely functions to minimize ankle moments.2 FFS runners slightly plantarflex (−12.5°) their ankle joints at impact, RFS runners slightly dorsiflex their ankle joints (1.2°; Fig. 4 and Fig. 5),3, 11, 12, 13, 14 and 19 while shifters alter their kinematics to correspond to the two styles of running. Typically, running involves a quick plantarflexion at heel contact before dorsiflexion,2, 4, 16, 26, 30, 31 and 32 but only for RFS runners (Fig. 4).

, 1987). These connections were likely the result of incomplete pruning of retinal afferents during development, as LGN neurons initially receive weak input from more than ten RGCs of mixed sign, but eventually www.selleckchem.com/products/PLX-4032.html receive only one or two dominant inputs once the pathway matures (Liu and Chen, 2008). Blocking On activity in the retina removes a major source of excitatory drive to On-center LGN neurons. This decrease in excitatory drive likely leads to numerous changes in the intrinsic membrane properties of LGN neurons and the composition of their postsynaptic receptors. Past work in

the peripheral nervous system has shown that decoupling skeletal muscle cells from their afferent input leads to an overall increase in input resistance, an increase in the number of acetylcholine receptors, and a general increase

in excitability (Berg and Hall, 1975). Likewise, blocking retinal activity in rat pups results in a scaling up of excitatory synaptic currents in visual cortex (Desai et al., 2002). In addition to these possible mechanisms, silent synapses may also play a role in the emergence of Off responses from On-center LGN neurons (Liao et al., 2001). Evidence indicates that adult retinogeniculate synapses typically contain both AMPA and NMDA receptors (Esguerra et al., 1992). If synapses from mismatched Off ganglion cells are instead silent and express only NMDA receptors, then these synapses could become rapidly activated with selleck the insertion of AMPA receptors. In support of this possibility, Chen et al. (2002) demonstrated that sustained afferent activity can lead to rapid short-term plasticity in the LGN through a process involving regulation of both AMPA and NMDA receptors and an overall desensitization of synapses.

In conclusion, we have identified a robust form of plasticity in the adult LGN whereby intraocular injections of APB lead to a rapid emergence of Off-center responses from On-center neurons. Our results suggest this plasticity likely relies on a rapid strengthening of weak or silent inputs from the retina. Moreover, all these results indicate that visual neurons in the adult thalamus are capable of providing visual information to the cerebral cortex in the absence of their primary afferent drive. For the On to Off plasticity identified here, cortical reorganization would likely follow thalamic plasticity for this information to prove useful for vision. Given the challenges the visual system encounters during its lifetime—challenges including injury, stroke, and disease—it is critical that we increase our understanding of the circuits capable of plasticity in the adult brain. Fifteen adult cats (>6 months old, both sexes) were used in this study. All surgical and experimental procedures were performed in accordance with guidelines from the National Institutes of Health and were approved by the Animal Care and Use Committee at the University of California, Davis.

However, we found a pronounced asymmetry in the effects of attending to preferred versus null stimuli in the receptive fields of MT neurons (Figures 4B and 4C). Although this asymmetric effect of attention can be seen in previously reported data from MT (Lee and Maunsell, 2010), we are unaware of any treatment of its origins. However, some existing models of the effects of attention can account for this asymmetry (Ghose and Maunsell, 2008 and Lee and Maunsell, 2009). Tuned

normalization provides a ready explanation for this asymmetric effect of attention. In Equation 3B attention to a null stimulus can be largely discounted with tuned normalization. Its effect on direct excitatory drive is small because the stimulus is not preferred (LN ∼0), and its effect on normalization is small because it is weighted by the tuning of the normalization (α < selleck kinase inhibitor 1). The ability of tuned normalization to account for both the range of modulation of neuronal responses when shifting attention between a preferred and null stimulus in the receptive field and for the asymmetry of this modulation gives strong support to its importance in both sensory find protocol processing

and modulation by attention. While attention to the preferred stimulus when it was paired with a null stimulus brought responses close to those seen when the preferred stimulus was presented alone, this should not be viewed as an invariant outcome from attention to a preferred stimulus. The

amount by which attention modulates neuronal responses depends greatly on the effort that the subject puts into the task (Spitzer et al., 1988 and Boudreau et al., 2006). It is likely that if the direction change-detection task had been easier (e.g., the changes were much larger), the monkeys would have directed less attention to the cued location. We expect that the asymmetry in the modulations from attention to the preferred stimulus versus attention to the null stimulus would persist as the absolute magnitude of the modulations varied, but that will need to be tested experimentally. All experiments followed the protocols approved by the Harvard Medical School Institutional MycoClean Mycoplasma Removal Kit Animal Care and Use Committee. Two male rhesus monkeys (Macaca mulatta) weighing 8 and 12 kg were each implanted with a head post and a scleral search coil under general anesthesia. Following recovery, each animal was trained on a motion direction change-detection task. Throughout each trial, the animal maintained fixation within ± 1° of a small white spot presented at the center of a monitor (44° × 34°, 1024 × 768 pixels, 75 Hz refresh rate, gamma-corrected) on a gray background (42 cd/m2) until the change detection.