The OFT is a behavioral test for assessing anxiety level and exploration activity in rats ( Borelli et al., 2004; Liu et al., 2010; Prut and Belzung, 2003). As a control experiment, we tested one anxiolytic drug, diazepam, and compared the results with saline- and vehicle-treated rats. Rats that did not receive lentiviral-shRNA infusions were

placed into the open field arena 30 min after i.p. injection of saline, vehicle (0.5% Tween 20 in saline), or diazepam (1.0 mg/kg in vehicle solution). Diazepam-treated rats displayed anxiolytic-like behaviors as defined by increased number of center square entries ( Figure 5C), duration of center square entries ( Figure 5D) and distance traveled in the center square ( Figure 5E) compared to saline-treated or vehicle-treated rats, confirming anxiolytic-like behaviors in this Rigosertib purchase behavior paradigm (see also Figure S4). Surprisingly, rats infused with lentiviral-shRNA-HCN1 into the dorsal CA1 region displayed significantly larger number of center square entries ( Figure 5C), longer duration of center square entries ( Figure 5D), and longer distance traveled

in the center square ( Figure 5E) compared to shRNA-control-infected rats, indicating less anxiety-like behavior in shRNA-HCN1-infected animals. For exploration activity, diazepam-treated rats showed significantly increased total distance ( Figures 5B and Perifosine manufacturer 5F), consistent with diazepam-induced hyperexploration ( Ennaceur et al., 2010). Like diazepam-treated rats, shRNA-HCN1-infected rats also showed significantly longer total distance traveled than shRNA-control-infected rats ( Figures 5B and 5F), indicating more exploration in the novel open field environment. To further confirm the anxiolytic-like effect of HCN1 knockdown in the dorsal CA1 region, we used an elevated plus maze (EPM) test to assess anxiety level of these animals. The EPM

test is a pharmacologically validated behavioral test for evaluating anxiety responses of rodents ( Pellow et al., 1985). Rats were allowed to explore on the elevated plus maze 30 min after i.p. injection of saline, vehicle (0.5% Tween 20 in saline), or diazepam (1.0 mg/kg in vehicle solution) for 6 min. Diazepam-injected rats displayed anxiolytic-like behaviors as defined by increased percentage of time spent in open arms ( Figure 5H) isothipendyl without significant change in total arm entries ( Figure 5I), confirming anxiolytic-like behaviors in this paradigm. Like diazepam-treated rats, shRNA-HCN1-infected rats displayed significant increase in the percentage of time spent in open arms ( Figure 5H) without significant alteration in total arm entries ( Figures 5I and S5) compared to shRNA-control-infected rats, indicating anxiolytic-like behavior. Taken together, knockdown of HCN1 in the CA1 region of the dorsal hippocampus produced anxiolytic-like effects in the open field test and the elevated plus maze test.

Parkin is an E3 ubiquitin ligase that is rapidly recruited to mitochondria in a PINK1-dependent manner in response to loss of mitochondrial membrane potential (Narendra et al., 2008, 2010). Parkin recruitment results in ubiquitination of mitochondria, followed by mitochondrial fission, clustering, and subsequent clearance of damaged mitochondria (Matsuda et al., 2010; Narendra et al., 2008; Narendra et al., 2010). To XAV-939 cell line address the hypothesis that VCP participates in the PINK1/Parkin pathway, we first assessed whether VCP is recruited

to mitochondria in response to depolarization. We used HeLa cells stably expressing YFP-Parkin (HeLa cells don’t show detectable endogenous Parkin expression, data not shown) and transfected plasmids expressing VCP-mCherry and mito-Cerulean (Cerulean fluorescent protein tagged with a mitochondrial targeting sequence). In untreated cells, Parkin and VCP were both distributed diffusely with no colocalization with mitochondria. However, 3 hr after treatment with the mitochondrial uncoupling agent carbonyl cyanide m-chlorophenyl-hydrazone (CCCP), virtually all of the YFP-Parkin and VCP-mCherry signal colocalized with mito-Cerulean, illustrating recruitment to the mitochondria (Figure 3A). We also generated mouse embryonic fibroblasts (MEFs) stably expressing mito-Cerulean to enable monitoring

of mitochondria. These cells were cotransfected with plasmids selleck screening library else expressing mCherry-Parkin and VCP-EGFP, which as expected

were distributed diffusely throughout untreated cells. Within 3 hr of treatment with CCCP, mCherry-Parkin and VCP-EGFP signals were relocalized to mitochondria (Figure S3A). Notably, in the absence of exogenous Parkin we observed no recruitment of VCP to mitochondria in response to depolarization, suggesting that VCP recruitment is Parkin-dependent (Figure S3B). Entirely consistent with the results in HeLa cells and MEFs, we observed that VCP also was recruited to depolarized mitochondria in neuroblastoma-derived Sy5y cells (Figure S4) and myoblast-derived C2C12 cells (Figure S5). Thus, VCP is corecruited to depolarized mitochondria in concert with Parkin in a wide variety of cell types. To characterize mitochondrial recruitment of Parkin and VCP in detail, we performed dynamic imaging in HeLa cells expressing VCP-EGFP and mCherry-Parkin after treatment with CCCP. We consistently observed that recruitment of mCherry-Parkin to mitochondria preceded recruitment of VCP-EGFP (Figures 3B–3D and Movies S1 and S2). Indeed, in an analysis of 35 sequential movies of individual cells we found that Parkin relocalized to mitochondria approximately 20 min after CCCP treatment and that VCP followed Parkin approximately 15 min later (Figures 3C and 3D). We sought to examine VCP recruitment to mitochondria in a cell type that expresses endogenous Parkin.

When utilizing the rabies virus as a traditional retrograde tracer, virus particles

find more are injected at high titer into the brain region of interest, spread through the extracellular space, and are then taken up at axon terminals (Figure 7F, top). We noted not only a large absolute number of labeled neurons in the SNc using this method (Figures 7D and 7E), but also that the proportion of labeled SNc cells compared to the total number of labeled neurons in the brain was much higher than observed using the monosynaptic rabies virus. Our data indicated that 7.6% ± 0.3% (mean ± SEM, n = 5) of the total input neurons labeled in the brain using this assay arose from SNc (Figure 7F, bottom). These values very closely mirror the estimated proportion of labeled neurons in SNc using other retrograde tracers (Pan et al., 2010), as well as the overall proportion of dopaminergic axon terminals in striatum previously determined through EM (Groves et al., 1994). This indicates that rabies virus is very efficiently taken up at dopaminergic axon terminals, suggesting that monosynaptic

spread of rabies virus from direct- or indirect-pathway MSNs is limited by some other factor (see Discussion). Furthermore, the similar amount of synaptic input to direct versus indirect-pathway MSNs indicates that differential http://www.selleckchem.com/products/Vorinostat-saha.html dopamine signaling in MSN subtypes does not arise from differences in anatomical connectivity. The dorsal raphe nuclei provided some synaptic input to both pathways (1.1% ±

0.8% in D1R-Cre mice, 0.1% ± 0.1% in D2R-Cre mice) but the total number of synaptic inputs was relatively small. The small amount of serotonergic input again suggests that neuromodulatory streams may provide relatively little direct synaptic input to striatal MSNs. However, the small total number of counted inputs, combined with high variability in labeling, prevented a direct statistical comparison between synaptic and total serotonergic input. Direct serotonergic input to the dorsal striatum has been previously described (Pan et al., 2010 and Vertes, 1991), but its potential functional roles are only beginning not to be explored (Di Matteo et al., 2008). Minor inputs (<1% of total inputs, but documented in at least three animals), were also documented from the pedunculopontine tegmental nucleus (PPTg), subthalamic nucleus, hypothalamus, and basal nucleus of Meynert. The projection from PPTg to the dorsal striatum has been described in other animal models (Nakano et al., 1990 and Saper and Loewy, 1982), suggesting that PPTg to dorsal striatum connectivity is highly conserved across species. The subthalamic nucleus has also been shown to provide some direct input to dorsal striatum in mice (Pan et al., 2010), indicating high levels of interconnectivity between mouse basal ganglia nuclei.

In many cases, a functional role has been demonstrated on the basis of pharmacological blockade, knockout, or knockdown. For example, Craner et al. (2005)

demonstrated that sodium channel blockade with TTX attenuates phagocytosis by 40% in cultured microglia. They also showed that the phagocytic capacity of microglia derived from med mice, which lack Nav1.6 channels ( Kohrman et al., 1996), is 65% lower than that of microglia from wild-type (WT) mice. Black et al. (2009) observed that the clinically used sodium channel blocker phenytoin significantly reduces the phagocytic activity of microglia by 50%–60% ( Figure 2). These studies also showed that TTX and phenytoin Dasatinib clinical trial attenuate the release of the proinflammatory cytokines interleukin 1-α (IL-1α), IL-1β, and tumor necrosis factor α (TNF-α) from stimulated Lapatinib datasheet microglia while having minimal effects on the release of IL-2, IL-4, IL-6, IL-10, monocyte chemotactic protein 1 (MCP-1), and transforming growth factor α (TGF-α). Phenytoin and TTX also significantly decrease ATP-induced migration of microglia. Supporting a role for Nav1.6 in the pathway leading to microglial migration, the level of ATP-induced migration of microglia cultured from med mice is significantly lower than that of cells from littermate WT mice ( Black et al., 2009). Another line of evidence of a novel contribution

of sodium channels—in this case the “cardiac” Nav1.5 channel—to the function of nonexcitable cells was provided by Carrithers et al. (2007), who demonstrated the expression of Nav1.5 within phagosomes of activated human macrophages by immunocytochemistry and immunogold electron microscopy (Figure 3). The expression of Nav1.5 was restricted to late endosomes of these cells and was not detected in early endosomes or on the macrophage plasma membrane. Evidence of a role for Nav1.5 in macrophage function was provided by the demonstration that TTX at 10 μM (a concentration that blocks Nav1.5) and gene knockdown of Nav1.5 with small hairpin RNA (shRNA) inhibit phagocytosis by these cells. Using time-resolved

fluorometry, Carrithers et al. (2007) also demonstrated Sclareol that the sodium channel activator veratridine reduces intraendosomal pH and intraendosomal [Na+] and that 10 μM TTX blocks lipopolysaccharide-induced acidification of the intraendosomal compartment in both purified endosomes and intact macrophages. These results suggest a model in which Nav1.5 channels, located intracellularly within the membrane of late endosomes, provide a route for Na efflux, which counterbalances proton influx, and thereby maintain electroneutrality during acidification, which is one of the final stages of phagocytosis. Noting that pH regulates the current of Nav1.5 (Khan et al., 2006), Carrithers et al. (2007) suggested that the expression and activity of Nav1.

, 1996), and subsequent studies support the hypothesis that opioid ligand effects are not adequately described by a single “dimension” of agonist activity (Whistler et al., 1999; Borgland et al., 2003; Pradhan et al., 2010; Arttamangkul et al., 2006). This concept remains controversial, however, particularly with regard to understanding the effects of morphine (McPherson et al., 2010; Molinari et al., 2010). Nevertheless, the general idea that some drugs promote regulated endocytosis of opioid receptors out of proportion

to conventional estimates of relative agonist activity is increasingly recognized (Rivero et al., 2012). Recent mechanistic data provide independent support for this concept because opioid receptor engagement with arrestins and subsequent clustering in CCPs, key initiating events affecting the rate of agonist-induced endocytosis, require multisite phosphorylation of the receptor’s cytoplasmic tail. Detailed analysis of discrete selleck kinase inhibitor phosphorylated receptor forms generated in intact cells, by quantitative mass spectrometry

applied to isotope-labeled cells, indicates that this multisite requirement renders endocytosis inherently nonlinear with respect to receptor activation (Lau et al., 2011). This principle for generating nonlinearity Selleckchem Pictilisib by multiphosphorylation is reminiscent of how multiphosphorylation can produce “ultrasensitive” responses in other biological contexts (Nash et al., Thymidine kinase 2001; Ferrell, 1996) and is a particularly attractive strategy for integral membrane proteins such as 7TMRs because significant nonlinearity can occur even in the presence of an excess local concentration of kinase (Dushek et al., 2011). Accordingly, nonlinear control by multisite phosphorylation may underlie how apparently complex differences in the regulatory effects of drugs—variously described in terms of “functional selectivity,” “multidimensional” efficacy, or “agonist bias”—are manifest at the cellular level. One function of 7TMR endocytosis is to initiate a multistep trafficking pathway mediating receptor delivery to lysosomes, a proteolytic organelle in which many

7TMRs are destroyed (Figure 1A). When a sufficient fraction of the overall cellular receptor pool is depleted through this pathway, as can occur under conditions of prolonged or repeated ligand-induced activation, cellular signaling responsiveness to neuromodulator is attenuated or “downregulated” (Tsao et al., 2001). Endocytic downregulation of delta opioid neuropeptide receptors by delivery to lysosomes, first recognized in cultured neuroblastoma cells (Law et al., 1984), has been directly shown in vivo and correlated with development of physiological tolerance to opioid drugs (Pradhan et al., 2009; Scherrer et al., 2006). Individual 7TMRs differ greatly in the efficiency with which they traffic to lysosomes after endocytosis, and this contributes to receptor-specific differences in endocytic regulation (Tsao and von Zastrow, 2000).

Thus, abnormal patterns of activity during development, or disruptions in activity-dependent transcription factor cascades, may account for some of the laminar, morphologic, and synaptic defects observed in a variety of neurodevelopmental disorders. All animals were treated in compliance with Yale IACUC and U.S. Department of Health and Human Services guidelines. We maintained and bred Sert-Cre+/−;Vglut1+/−;Vglut2fl/+,

Sert-Cre+/−;Vglut1+/−;Vglut2fl/−, and Vglut1+/−;Vglut2fl/fl mice on a mixed C57B/6J and CD1 background and used Vglut1−/−;Vglut2fl/− mice as littermate controls for ThVGdKO (Sert-Cre+/−;vglut1−/−;vglut2fl/fl, and Sert-Cre+/−;Vglut1−/−;Vglut2fl/−) mice throughout unless otherwise explicitly Paclitaxel ic50 stated. Dcdc2a-Gfp and Fezf2-Gfp transgenic mice were obtained from GENSAT. As previously described (Iwasato et al., 2008), CO and Nissl stain was performed on flattened tangential sections through the barrel cortex. CO was depicted using a solution of 3 mg cytochlomec, 0.4 g sucrose, and one 3,3′-diaminobenzidine tablet (Sigma) in 10 ml PBS. Nissl bodies were depicted with a 2% cresyl violet solution.

Stereologic quantification of Nissl sections was performed on mounted slides at high magnification (40× or 63×) with Neurolucida Software (MicroBrightfield) blind to genotype. Statistical analysis was selleck screening library performed with two-tailed Student’s t tests and one-way ANOVA. Significance level was set at p < 0.05. One microliter of Cre-dependent AAV2/9 CAG.FLEX.tdTomato.WPRE.bGH virus (University of Pennsylvania Vector Core Cat AV-9-ALL864) was injected into the thalamus using a Nanoject (Drummond Scientific) for demonstration aminophylline of thalamocortical afferents with tdTomato. Biocytin labeling of L4 neurons was performed on acute thalamocortical slices using whole-cell patch pipettes that contained 10 mM Biocytin in addition to the standard whole cell

solution. Labeled neurons were depicted with confocal and multiphoton laser microscopy (LSM duo710, Zeiss) and reconstructed using Neurolucida (MBF Bioscience). In situ hybridization was performed with Digoxigenin-11-UTP and/or Fluorescence-12-UTP (Roche) probes on 60 μm free-floating coronal sections. Immunohistochemistry was performed on free-floating 60-μm-thick thalamocortical or coronal sections, and images for fluorescence quantification were acquired with a Zeiss Axio Imager.Z2 or LSM 510 Meta microscope using the same exposure time and background subtraction for all genotypes. Quantification of laminar distribution was performed on images with the pial surface at the upper edge and the cortex depth divided into ten equal bins below the pial surface. Cells in each bin were counted using ImageJ (NIH) and Volocity (PerkinElmer) software and reported as a percentage of total cells counted blind to genotype. Statistical analysis was performed with two-tailed Student’s t tests and one-way ANOVA with significance level set at p < 0.05.

, 2009). Given that these adhesive contacts must be shed upon differentiation, we next investigated whether the FK228 pro-differentiation actions of Foxp4 might involve changes in N-cadherin expression or subcellular distribution. In transverse sections of the spinal cord, we noticed that there was a slight thinning of apical N-cadherin staining around the region of the pMN (Figure 3A, bracket). This difference was more clearly revealed by imaging the apical surface of the neuroepithelium in an open book preparation, which showed distinct bands of N-cadherin staining corresponding to the different

progenitor domains along the dorsoventral axis (Figures 3B–3E and S5A–S5J). N-cadherin was strikingly reduced wherever Foxp4 was present (Figures 3B and 3D–3F; averaged correlation R2 = −0.722). This antithetical pattern was specific to Foxp4 and N-cadherin as there was no correlation between the expression of Foxp4 and other AJ

components such as aPKCζ or the NPC marker Sox2 ( Figures 3B, 3C, and S5B–S5L). Under conditions of Foxp4 misexpression, the electroporated spinal cords displayed a dramatic loss of N-cadherin protein and disruption in the ultrastructure of the neuroepithelium (Figures 3G, 3K, 3M, and 3Q). These changes coincided with an aberrant distribution or loss of other AJ components Selleckchem BKM120 including β-catenin, f-actin, aPKCζ, and Par3 (Figures 3H, 3I, 3N, and 3O, and data not shown) and cytoplasmic Rolziracetam accumulation of Numb (Figures 3L, 3M, and 3R). The radial morphology of NPCs was also severely disrupted (Figures 3H, 3I, 3N, and 3O), and markers of dividing cells such as BrdU incorporation and phosphohistone H3 staining were reduced (data not shown). Nonetheless, integrin-laminin interactions at the basolateral membrane remained intact (Figures 3J and 3P), suggesting

that the effects of Foxp4 misexpression are primarily directed to apical attachments. Identical results were seen with misexpression of Foxp2 and Foxp1 (Figure S3), indicating that all of the Foxp proteins have the capacity to repress N-cadherin expression and disrupt AJs under these conditions. The combined knockdown of Foxp2 and Foxp4, in contrast, led to an ∼1.5–2-fold upregulation of N-cadherin mRNA and protein within the pMN and extensive accumulation of Numb at the apical membrane of these cells (Figures 3S, 3T, and S5M–S5Q). The effects of the shRNA constructs were specific, as the knockdown phenotype was completely reversed by coelectroporation of a Foxp4 expression vector, often resulting in the Foxp4 misexpression phenotype (Figures S2J–S2R). Together, these data indicate that Foxp2 and Foxp4 play a crucial role suppressing the expression of N-cadherin and disassembling neuroepithelial AJs (Figure 3U).

However, unlike RA-LTMRs that associate with guard and awl/auchene follicles of the mouse, Aδ-LTMR lanceolate endings are found around awl/auchene and zigzag, but not guard hair follicles (Li et al., 2011) (Figure 1B). C-LTMRs. Though C fibers are often associated with painful stimuli, mechanoreceptors with conduction velocities within the C fiber range were described in the cat as early as 1939

by Ingve Zotterman (1939) and suggested to be associated with “tickling” sensations. Subsequent research on C-LTMRs indeed established that not all cutaneous sensory receptors Selleck UMI-77 with afferent C fibers are concerned with relaying noxious information (Douglas and Ritchie, 1957, Iggo, 1960 and Iggo and Kornhuber, 1977). In addition, since sensory C fibers are three to four times more numerous than A fibers, C-LTMRs far outnumber the myelinated fibers innervating skin (Li et al., 2011). Like Aδ-LTMRs, C-LTMRs are exquisitely sensitive to skin indentation but are maximally activated by stimuli that move slowly across their receptive

field and are thus suggested to be “caress BMS-354825 cost detectors.” The C-LTMR physiological profile is unique among hairy skin LTMRs. Most notably, they exhibit an intermediately adapting property, with a modest sustained discharge during a maintained stimulus (Table 1). Unlike other hairy skin LTMRs, C-LTMRs also show a high incidence of after-discharge, even several seconds after the stimulus is removed. The shape of their action potentials is characteristic of C fibers, with broad waveforms displaying a prominent hump on the falling phase. As with Aδ-LTMRs, C-LTMRs are sensitive to rapid cooling, but not warming, of the skin; however, it is unclear whether the temperatures to which these receptors respond to are physiologically relevant

for the behaving animal. One of the most striking features of C-LTMR responses is that they are only found in hairy skin. Though less common in nonhuman primate skin, C-LTMRs are present in human hairy skin and are speculated to play a role in mediating “emotional touch” (Kumazawa and all Perl, 1977, Löken et al., 2009, McGlone et al., 2007 and Vallbo et al., 1993). Indeed, in humans lacking large myelinated fibers, activation of C-LTMRs is correlated with a sensation of pleasantness often associated with activation of the insular but not the somatosensory cortex (Björnsdotter et al., 2009 and Olausson et al., 2002). The peripheral and central anatomy of C-LTMRs was largely unknown until recent studies in the mouse postulated that they may have several anatomical forms in hairy skin. Postrecording intracellular labeling of C-LTMRs identified in ex vivo skin nerve recordings revealed that C-LTMRs express tyrosine hydroxylase (TH). By utilizing a CreER knocked into the TH locus, Li et al.

We especially thank Ron Habets as well check details as Sebastian Munck, Pieter Baatsen, and Jan Slabbaert, and other members of the P.V., W.R., and W.V. labs for help and comments. Support was provided by a Marie Curie Excellence grant (MEXT-CT-2006-042267), an ERC Starting Grant (260678), FWO Grants G094011, G095511, G074709, and G025909, the Research Fund KU Leuven: BOF-OT and GOA 11/014, Interuniversity

attraction Poles (IUAP) program P6/43 of the Belgian Federal Science Policy Office, the Motor Neuron Disease Association UK (6046), The European Community’s Health Seventh Framework Programme (FP7/2007-2013; 259867), a Methusalem grant of the Flemish Government, the Francqui Foundation, the Hercules Foundation (project AKUL/09/037), and VIB. W.V. is supported by an FWO postdoctoral grant, M.F. by an IWT predoctoral grant, L.E.J. by a predoctoral VIB fellowship, and W.R. by a E. von Behring Chair for Neuromuscular and Neurodegenerative Disorders. “
“Glutamatergic synapses provide

the majority of excitatory neurotransmission in the brain, and the ionotropic receptors responsible for rapid information transfer at these contacts are N-methyl D-aspartate receptors (NMDARs) and α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPARs). NMDAR activation results in calcium-ion influx, which links synapse activation to intracellular signaling cascades BMN 673 research buy which control synaptic strength, neuronal excitability, and neuronal survival. NMDARs are heteromultimeric protein complexes containing two GluN1 subunits (a single gene) and two GluN2 (NR2) subunits, which are encoded by four genes in mammals (GluN2A-D; also known as NR2A-D) (Meguro et al., 1992 and Monyer et al., 1992). Contribution of GluN2 subunits to the NMDAR complex is precisely regulated during development, with early postnatal receptors containing exclusively GluN2B subunits, whereas increased incorporation of

GluN2A subunits occurs during a postnatal period of synapse maturation and cortical circuit refinement (Monyer et al., 1994 and Sheng et al., 1994). Homozygous GluN2B genetic knockout (KO) animals die on postnatal day 0 (P0) (Kutsuwada through et al., 1996). By contrast, GluN2A knockout animals are viable and fertile (Sakimura et al., 1995). Due in part to the lethality of the GluN2B knockout mutation, the role of this receptor subtype during development remains unclear. In addition, the relative role of GluN2B- versus GluN2A-containing NMDARs in synapse function has become a highly debated issue, with potentially distinct roles ascribed to these receptors in regimes of synaptic plasticity and metaplasticity (Yashiro and Philpot, 2008). Assigning unique functional roles to GluN2B-containing NMDARs during development is complicated by the fact that their exclusive expression means that specific loss of GluN2B also results in total loss of NMDAR signaling during this period.

, 2004), and in the thick/pale stripes of macaque V2 (Lu et al., 2010). The direction preference map in V4 showed some common properties as

those found in MT and V2, including similarity in domain size and the orthogonal relationship between preferred Alectinib supplier direction and orientation angles (Lu et al., 2010; Kaskan et al., 2010). However, the direction preference maps in V4 also showed features that are distinct from those found in all these other areas. First, V4 direction-preferring domains only appear in restricted regions, rather than in the entire V4 area. Second, many V4 direction-preferring domains appear to be isolated singulars, without any neighboring domains for other directions. Third, these domains overlap not only with orientation-preferring domains but also with color-preferring domains. It is understandable that a direction www.selleckchem.com/products/epacadostat-incb024360.html map in the ventral pathway may have a different clustering architecture than its counterparts in the dorsal pathway. A precedent for this principle was found, for example, in motion maps of V2 (Lu et al., 2010), where the direction maps differ in architecture from those found in MT (Malonek et al., 1994; Xu et al., 2004; Kaskan et al., 2010) or cat area 18 (Shmuel and Grinvald, 1996). Thus, this functional architecture may suggest a distinct functional computation in the visual system. Direction-preferring

domains found in previous studies either have been shown in an area not considered to signal color (e.g., MT; Malonek et al., 1994; Xu et al., 2004; Kaskan et al., 2010) or avoid color-preferring regions (e.g., in thick/pale stripes of V2; Lu et al., 2010). also Our data show that, in V4, about one fourth of direction-preferring pixels overlap with color-preferring pixels, suggests that these direction-selective neurons may be involved in detection of color motion. Another possibility is that motion cues in V4 are used for surface definition and thus are processed by surface-processing neurons, which were revealed by color versus luminance imaging (e.g., Figure 1D). These results,

however, differ from the findings in a recent fMRI-guided recording study in which color cells recorded from globs rarely showed direction selectivity (Conway et al., 2007). We noted that the V4 color glob neurons they recorded from were mostly from anterior wall of the lunate sulcus, while our imaging and recordings were all from dorsal part of the lunate gyrus. Therefore, it is possible that different parts of V4 may have different color-direction interactions. The separation of motion and color/form information in the primate visual system has been considered to be strong support for the concept of parallel processing of visual information. In particular, areas MT and V4 are often referred to as motion and color/form centers, respectively (Zeki et al., 1991).