, 2011, Majounie et al., 2012 and Renton et al., 2011). Since the discovery of pathogenic repeat expansions as a mechanism of disease in the 1990s, the list of neurodegenerative and neuromuscular disorders characterized by unstable

repeat expansions has grown to over 20 ( Brouwer et al., 2009, Pearson et al., 2005 and Todd and Paulson, 2010). Repeat expansions are classified as coding or noncoding according to their gene location, and the disease-causing mechanisms include protein gain-of-function (Huntington’s disease, HD), protein loss-of-function (FRAXA, FRDA), toxic RNA gain-of-function (DM1&2) (for reviews, see Brouwer et al., 2009, Gatchel and Zoghbi, 2005 and Todd and Paulson, 2010), and non-ATG-initiated translation (RAN) peptides ( Mori et al., 2013b) ( Ash et al., 2013). The repeat expansion in DM1 alters activities INCB018424 research buy of RNA binding proteins

(RBPs), including muscleblind-like 1 (MBLN1) ( Fardaei et al., 2002, Grammatikakis et al., 2011 and Miller et al., 2000). MBLN1 is sequestered in the nucleus by the repeat-containing RNA resulting in the formation of a pathogenic protein:RNA complex that, when visualized by RNA fluorescent in situ hybridization, form an intranuclear RNA foci, which leads to a loss of protein activity and reduces alternative splicing of other genes ( Kanadia et al., 2003 and Kanadia et al., 2006). Notably, intranuclear GGGGCC RNA foci have also been found in the motor cortex and selleck screening library spinal cord of C9ORF72 ALS/FTD patients ( DeJesus-Hernandez et al., 2011), suggesting that, like myotonic dystrophy, RNA toxicity plays a role in C9ORF72 neurodegeneration. To understand the pathogenesis of the C9ORF72 expansion and to develop possible therapeutics, we generated a collection of C9ORF72 ALS induced pluripotent stem cells (iPSCs) and differentiated Dichloromethane dehalogenase them into neurons (iPSNs). Using this model system, we discovered intranuclear C9ORF72 repeat-containing RNA foci in all tested human C9ORF72 iPSN cell lines. Furthermore, we identified several protein binding partners for the expanded GGGGCC RNA (GGGGCCexp) and confirmed that the RNA binding protein ADARB2 interacts with

nuclear GGGGCC RNA foci. In addition, we discovered aberrantly expressed genes in C9ORF72 cells and determined that C9ORF72 ALS iPSNs are highly susceptible to glutamate-mediated excitotoxicity. To validate the use of this iPSC model, we confirmed these expanded C9ORF72-related phenotypes in postmortem human ALS CNS tissue. Finally, iPSN treatment with novel antisense oligonucleotides (ASOs) that target the GGGGCCexp RNA sequence but do not lower C9ORF72 RNA levels mitigate all toxic phenotypes. Although RAN proteins, translated from the mutant GGGGCC expansion, are present in these iPSNs, they do not appear to contribute to the observed acute neurotoxicity. Taken together, these data support the theory that the generation of toxic RNA plays a major role in C9ORF72 ALS and that specifically targeted antisense can effectively prevent neurotoxicity.

, 2007). In each section, stacks of ∼1.5 mm × 1.5 mm × 0.05 mm were imaged using optimized mosaic optical-sectioning microscopy (Oberlaender et al., 2009) and an oil-immersion objective

(Olympus 100× UPLAN S APO, NA 1.4), yielding a voxel size of 0.184 μm × 0.184 μm × 0.5 μm. Manual postprocessing of individual sections (Dercksen et al., 2012), as well as automated alignment of reconstructed branches across sections (Dercksen et al., 2009), was performed using a custom-designed three-dimensional (3D) editing environment based on ZIBamira visualization software v2010.06 (Zuse Institute Berlin). Pia and barrel outlines were manually traced in each section at low resolution (Olympus 4× UPLAN S APO, NA 0.16) and added to the tracings in Neurolucida software (MicroBrightfield). Reconstructions INCB28060 ic50 were placed into a standardized coordinate system. The origin was defined as the center of the L4 barrel that INK1197 molecular weight contained the majority of the neuron’s axon (“the principal barrel”). The z axis was set to point dorsally, parallel to the vertical axis of the principal barrel. The x axis was defined as the line joining the centers of the principal barrel and the first rostrally neighboring barrel within the same row. Measurements were performed in ZIBamira and double checked in NeuroExplorer v9.03 (MicroBrightfield). Axon length per

individual column was determined by extrapolating the respective L4 barrel contours, rather than idealized barrels, along the vertical axis toward the pia and white matter. Supragranular, granular, and infragranular projections (i.e., above, within, and below the principal barrel) were measured for each column individually because barrel height

varied between columns. Average interbouton distances were obtained from high-resolution image stacks (100× objective, 0.2 μm optical sections). Horizontally projecting axonal segments were randomly selected for analysis because varicosities are difficult to unambiguously identify when an axon travels along the optical axis (vertically). Interbouton distances were determined by manually marking the 3D location of each bouton along the reconstructed axons. much Custom-written ZIBamira routines were used to measure distance along the axons between these markers. Measurements were performed for 1,835 boutons from axonal segments in ten different rats (six control and four deprived). IgorPro (WaveMetrics) was used for statistical analysis of morphological data. All reconstructions, analyses, and bouton counting were performed double blind (i.e., control and deprived groups were only known after reconstructions and analyses were finalized). An additional 11 adult rats were used for physiology experiments. Prior to surgery, whiskers were trimmed (n = 6) or sham trimmed (n = 5) for 8–25 days. Rats were initially anesthetized with isoflurane. A single craniotomy was made over a thin region of skull overlying the left barrel cortex (0.2 × 1.0 mm; centered 2.5 mm posterior to bregma and 5.

All ROIs were taken from

t maps corrected at FDR < 0.05, with a cluster threshold of 10 mm3 (10 contiguous voxels). In some cases, the FDR threshold was made more conservative, e.g., when the Small-OTS and Small-LO regions, which each VE-821 concentration have distinct peaks, were connected by voxels with lower t values. If any of the targeted ROIs were not present at FDR < 0.05, the threshold was lowered to FDR < 0.1. If no clear ROI was present at that threshold, then that ROI was not defined for that participant. ROIs were defined as the set of contiguous voxels that were significantly activated around the peak voxel identified from within a restricted part of cortex based on the anatomical position. For all ROI analyses, all ROIs were defined from the Big versus Small object experiment (independent dataset), and the response of these regions to different experimental conditions was assessed in subsequent experiments. For each subject and each ROI, GLMs were run on the average time series of the voxels in the ROI to obtain regression coefficients (betas) for the experimental conditions. For the subsequent experiments with 2 × 2 designs (Experiment 2: retinal size manipulation; Experiment 3: mental imagery), to evaluate the effects of selleck screening library each factor across observers, repeated-measures ANOVAs were run on the betas across observers for each ROI. This work was funded

by a National Science Foundation Graduate Fellowship (to Talia Konkle), Metalloexopeptidase and a National Eye Institute grant EY020484 (to Aude Oliva), and was conducted at the Athinoula A. Martinos Imaging Center at McGovern

Institute for Brain Research, MIT. We thank George Alvarez, Timothy Brady, Mark Williams, Daniel Dilks, and the reviewers for thoughtful comments on the manuscript. “
“A fundamental human ability in social environments is the simulation of another person’s mental states, or hidden internal variables, to predict their actions and outcomes. Indeed, the ability to simulate another is considered a basic component of mentalizing or theory of mind (Fehr and Camerer, 2007, Frith and Frith, 1999, Gallagher and Frith, 2003 and Sanfey, 2007). However, despite its importance for social cognition, little is known about simulation learning and its cognitive and neural mechanisms. A commonly assumed account of simulation is the direct recruitment of one’s own decision-making process to model the other’s process ( Amodio and Frith, 2006, Buckner and Carroll, 2007 and Mitchell, 2009). The direct recruitment hypothesis predicts that one makes and simulates a model of how the other will act, including the other’s internal variables, as if it is one’s own process, and assumes that this simulated internal valuation process employs the same neural circuitry that one uses for one’s own process.

, 2006; Becker and Rasmussen, 2008; Chanon and Hopfinger, 2008). Summerfield and colleagues (2006) found that visual search of complex scenes guided by recent experience is associated with activity in the hippocampus, a region known to be critical to episodic memory. Second, we tend

to remember information that is attended to during encoding and forget information that is ignored during encoding (Wolfe et al., 2007; Uncapher and Rugg, 2009). Recently, Uncapher and colleagues (2011) have shown that the effect http://www.selleckchem.com/Androgen-Receptor.html of attention on encoding can depend on how attention is engaged: under certain conditions, top-down attention can result in more effective memory encoding than bottom-up attention (see also Uncapher and Wagner, 2009). These two points of contact between visual attention and episodic memory have been the focus of the handful of studies that have examined the interaction

between these two systems. Episodic memory depends not only on the ability to encode information during the original event, but also on the ability to retrieve and interpret relevant information when it is required to achieve current goals. Although it is well known that visual attention can PI3K Inhibitor Library chemical structure modulate the encoding of information into memory, the critical question of how episodic memory and visual attention interact when people are attempting to retrieve episodic memories has not been thoroughly explored. Cognitive-behavioral research on source monitoring and memory distortions suggests that visual attention should play an important role in episodic

memory retrieval. The ability to emphasize the retrieval of specific perceptual details, while de-emphasizing the retrieval of other components of a memory, such as conceptual information or emotional associations, is a critical feature of episodic memory retrieval (Johnson et al., 1993; Schacter et al., 1999). Focusing on specific perceptual details is important for avoiding memory distortions (Johnson, 1997; Schacter et al., 1999), such as reality monitoring errors, which involve confusing material that was thought about or imagined with material that actually happened (Johnson et al., 1993). Attention to perceptual detail is also important for avoiding gist-based false recognition, which occurs when one mistakenly recognizes an item isothipendyl that has a general similarity to a previously encountered item: focusing on perceptual details that are diagnostic of an item’s prior presentation can lead to significant reductions in false recognition (Schacter et al., 1999; Gallo et al., 2004). Given the functional importance of attending to specific, diagnostic perceptual details stored in episodic memory, it seems likely that episodic retrieval should draw upon visual attention by directing attention toward the visual details of a cue that are relevant to the retrieval demands.

The work was funded in part by grants from NINDS (NS23868, NS23320) to S.T.B. “
“Presynaptic inhibition Apoptosis Compound Library solubility dmso onto axonal terminals, commonly provided by GABAergic transmission, regulates neurotransmitter release. GABA receptors on the axon hillock of

pyramidal cells (Nusser et al., 1996; Szabadics et al., 2006), on mossy fiber terminals of hippocampal granule cells (Ruiz et al., 2003), on cerebellar parallel fibers (Stell et al., 2007), and on retinal bipolar cell axon terminals (Shields et al., 2000; Vardi and Sterling, 1994) serve to modulate action potential firing and neurotransmitter release (Kullmann et al., 2005; Luscher et al., 2011). Although much is known about how presynaptic GABAergic

inhibition shapes neuronal output, mechanisms that regulate the development and maintenance of such inhibition onto axon terminals are not yet well understood. Here, we addressed the role of neurotransmission in the development, maturation, and maintenance of GABAergic synapses onto axonal terminals involved in modulation of neurotransmitter release. To do so, we took advantage of a well-characterized circuit in the mammalian retina, where glutamate PLX-4720 price release from axons is regulated by robust presynaptic GABAergic inhibition. At dim light levels, visual information from rod photoreceptors is conveyed to rod bipolar cells (RBCs), which relay the signal to amacrine cells in the inner retina (reviewed by Wässle,

2004). Specifically, RBCs contact GABAergic A17 amacrine cells (A17s) (Nelson and Kolb, 1985), which provide local feedback inhibition onto the rod bipolar cell axon terminals to modulate their release of glutamate (Chávez et al., 2006; Chun et al., 1993; Hartveit, 1999). In addition, RBC axon terminals also receive GABAergic drive from other widefield amacrine cells (Chávez et al., 2010; McGuire et al., Idoxuridine 1984). Unlike other parts of the brain in which GABAergic inhibition is mediated mainly by GABAA receptors, GABAergic input onto RBC axon terminals involves both GABAA and GABAC receptor types (Enz et al., 1996; Koulen et al., 1998). GABAA and GABAC receptors do not cocluster at the same synaptic site but are expressed at different postsynaptic sites on RBC axon terminals (Fletcher et al., 1998; Koulen et al., 1998). There are also functional differences between the two receptor types: GABAA receptors are less sensitive to GABA but have faster kinetics compared to GABAC receptors, and thus the two receptor types regulate different aspects of glutamate release from RBCs (Eggers and Lukasiewicz, 2006b; Sagdullaev et al., 2006). The diversity of GABA receptors on RBCs presents an ideal opportunity to investigate how neurotransmission regulates the development and maintenance of not only GABA receptors but also different GABA receptor types on the same axon terminal.

Brain tissue and neuronal cultures were fixed in 4% PFA, and postfixed in ice-cold acetone-methanol (1:1) at –20°C for 10 min. The immunostainings with rabbit anti-Arc and anti-Notch1 antibodies were performed using the TSA fluorescence amplification kit (Perkin Elmer). ImageJ software (NIH) was used to quantify fluorescence intensity of immunostainings with NICD1 (Figure 2A), EGFP (Figure S3B), and Notch1 (see legend for Figures 3C and 3D). Student’s t test was used to determine p values. Golgi-Cox staining (FD NeuroTechnologies) was performed according to the manufacturer’s instructions. Dendrite and spine lengths/widths were measured using Reconstruct software by the Neural Systems Laboratory (http://www.bu.edu/neural/Reconstruct.html).

Veliparib clinical trial Spine length and width data were analyzed using the Kolmogorov-Smirnov statistical test.

Transverse hippocampal slices (350 μm) were prepared from Notch1 cKO and control mice, and maintained in artificial cerebrospinal fluid at room temperature. Data were collected using an Axopatch 1D amplifier (Molecular Device); signals were filtered at 2 kHz, digitized at 10 kHz, and analyzed using pCLAMP 8 software (Molecular Device). The authors thank Jason Shepherd, Richard Flannery, Marlin Dehoff, Vera Goh, and Keejung Yoon for technical and intellectual input during the course of this project. NVP-BGJ398 nmr We also thank Ted Dawson and Jay Baraban for critically reading the manuscript. Funding for this work came MTMR9 from the Institute for Cell Engineering at Johns Hopkins University (N.G.), a NARSAD Young Investigator Award (N.G), the James S. McDonnell Foundation (N.G.), and the National Institute of Mental Health (P.F.W.). “
ent in each arm and number of entries in each arm using the

StopWatch Plus software. The social interaction testing was carried out in three sessions using a three-chambered box with openings between the chambers. The Morris water maze test was done according to a published protocol (Vorhees and Williams, 2006). Details for all behavioral tests are provided in the Supplemental Information. Neuronal cultures were prepared from the hippocampus of E17.5 embryos and plated on poly-L-lysine-coated 60 mm dishes or 18 mm glass coverslips. Neurons were exposed to pharmacological manipulations after 14 days in vitro (DIV). For Sindbis virus infection, the pSinRep5 vector (Invitrogen) was used to generate viruses expressing either full-length Arc or a nonfunctional form with residues 91–100 deleted (Chowdhury et al., 2006). Synaptosomal fractions were prepared as previously described (Blackstone et al., 1992). Standard western blot protocols were used. Details regarding fractionation, immunoprecipitation, and western blot protocols are provided in the Supplemental Information. Quantitation of individual protein bands was done using ImageJ software. Values were averaged between experiments, and Student’s t test was used to compare samples.

The results gave Kd values with 95% confidence intervals of 2.0 μM (0.18–2.27 μM) for E156A, 6.7 μM (6.4–7.1 μM) for L163A, and 13.0 μM (10–15 μM) for the S165G/T168A double mutant. The I164A mutation produced a much greater disruption, such that we can set only a lower limit on the Kd of 200 μM or larger. find protocol We also screened two additional sets of KA2 mutants in regions of the structure which might be anticipated to affect heterodimer formation. The first set tested, KA2 C64S/C315S, targeted the disulfide bond which holds loop three in place (Figure 5A). The second set targeted Lys148 and Glu150 at

the N terminus of α-helix E, which were candidates for mediating contacts with His105, Ser108 and Asp109 in domain R1 of the GluR6 protomer. However, both the C64S/C315S and K148A/E150A KA2 double mutants produced no change in oligomerization when mixed with either GluR6Δ2 selleck inhibitor or GluR6Δ2 F58A and analyzed by UV/RI/MALS-SEC (Figure S5). The lack of effect of

loop 3 disulfide bond disruption likely occurs because, in a heterodimer assembly with GluR6, loop 3 of the KA2 subunit is held in place by other contacts such as the hydrogen bond between the main chain carbonyl oxygen of Cys315 and the side chain of Lys62 in the GluR6 subunit. We were unable to test the effect of the GluR6 C65S/C316S mutant, because this construct could not be expressed at levels sufficient for biochemical analysis, possibly due to misfolding. The interactions made by Lys148 and Glu150 with

the GluR6 subunit are formed in solvent exposed loops with weak electron density, and it is likely that this region is quite mobile, since our results reveal that it does not contribute to dimer stability. To estimate the strength of the interactions underlying dimer formation we purified a series of 15 mutant ATD proteins and measured their Kd for homodimer and heterodimer formation using SV experiments. To select mutant combinations suitable for analysis by SV we performed SEC-UV/RI/MALS experiments to assay for either depletion of the enough monomer KA2 peak when mixed with GluR6Δ2, or an increase in dimer peak when mixed with GluR6Δ2F58A (Figures 1C and S5A; Table S1). Out of 30 combinations tested, 13 pairs were selected for analysis by SV; examples of isotherms for weighted-average sedimentation coefficients for KA2 mutants mixed with GluR6Δ2F58A and GluR6Δ2 are shown in Figures 4C and S5C, respectively. To calculate ΔΔG values we used SV measurements for the GluR6Δ2 homodimer Kd (250 nM), the KA2 homodimer Kd (350 μM), and the GluR6Δ2/KA2 heterodimer Kd (11 nM), as reference values (Table S1). The formation of GluR6Δ2/KA2 heterodimers is favored by 6.04 kcal/mol compared to the KA2 subunit homodimer Kd.

Note that this procedure extracts the time-varying envelope amplitude of each band-pass-filtered signal. Next, the BLP signals were further filtered into selleck products slow (<0.1 Hz) fluctuations (two other frequency bands [0.1–1 Hz and >1 Hz] were also computed for comparison) using a second-order, zero-phase Butterworth band-pass filter. We calculated Pearson’s correlation coefficients between all possible pairs of ROIs (1) over the entire time course of the filtered BLP signals (“long epochs”) and (2) over the stable-eye epochs (“short epochs”; 135 ± 69 epochs per recording session; a total of 58 sessions). The significance of correlations was assessed using one-sample

t tests on Fisher Z-transformed coefficients. Coherence Analysis. RG7204 research buy We used multitaper methods

(three Slepian tapers, providing an effective taper smoothing of ± 4 Hz; Mitra and Pesaran, 1999) to calculate the coherence Cxy(f): Cxy(f)=|Sxy¯(f)|Sx¯(f)Sy¯(f),where Sx(f) and Sy(f) are the spectra of LFP time series, and Sxy(f) is the cross-spectrum. Coherence values range from zero to one, where zero coherence means that the LFPs are unrelated, and a coherence of one means that the LFPs have a constant phase relationship. We Fisher transformed coherence values and accounted for the different number of stable-eye epochs in each resting-state session according to: Cxy_t(f)=tanh−1(Cxy(f))−12m−2,where Cxy_t is the transformed coherence, and m is the product of K and the number of stable-eye epochs ( Bokil et al., 2007). We rejected the null hypothesis of no significant coherence between two ROIs only when the coherence was above zero (based on jackknife estimates of the variance) across a frequency range greater than the bandwidth (i.e., 8 Hz), to account

for multiple comparisons ( Bokil et al., 2007). Cross-Frequency Coupling. We measured cross-frequency coupling between low-frequency oscillations and gamma power using the SI ( Cohen, 2008). There were two reasons for using this measure: (1) the SI can be reliably computed on the short stable-eye Bumetanide epochs examined in our study; and (2) the SI can capture dynamic changes in cross-frequency coupling. There were three processing steps to calculate the SI. First, we extracted gamma power time series for given frequency bands whose central frequency ranged from 30 to 100 Hz, stepped in 5 Hz increments, with a bandwidth of ± 5 Hz. Second, for each of the theta, alpha, low-beta (13–20 Hz), and high-beta (20–30 Hz) bands, we identified the low frequency with which the gamma power time series might synchronize. (The aim here was to identify the dominant frequency at which the gamma power time series oscillated.) Third, we identified the peak of the power of the gamma frequency envelope time series, extracted the phase time series from both the gamma- and low-frequency bands (low-frequency bandwidth ± 1.

, 2002). However, the downstream effectors and precise actin mechanisms that control the directional motility of growth cones remain to be fully determined. Actin filaments are built

through a balancing act of filament assembly at the barbed ends and disassembly at the pointed ends, and these rates are influenced by a wide http://www.selleckchem.com/products/azd5363.html range of regulatory proteins. Moreover, an even larger number of accessory proteins are present in cells to organize actin filaments into distinct networks in specific subcellular locations (Chhabra and Higgs, 2007, Pollard et al., 2000 and Pollard and Borisy, 2003). For example, lamellipodia and filopodia, two membrane protrusions that function in growth cone movement and environmental sensing, respectively, are based on distinct F-actin structures. Gefitinib order The former contains a meshwork of short, branched actin filaments that depends on the Arp2/3 nucleation complex, whereas the later is supported by long unbranched actin filaments involving formin family of molecules and regulated by Ena/Vasp proteins. A number of excellent reviews are available that have provided comprehensive coverage on the actin structures and dynamics of lamellipodia and filopodia in both nonneuronal cells and nerve growth cones (Dent et al.,

2011, Lowery and Van Vactor, 2009, Pollard and Cooper, 2009 and Rodriguez et al., 2003). Here, we will only discuss a few of the actin regulatory molecules whose function in growth cone motility is complex Carnitine palmitoyltransferase II and remains to be fully understood. In vertebrate cells, a large array of regulatory proteins control the actin network and its dynamics through a diverse set of actions, including filament nucleation, severing, crosslinking, and end capping, as well as monomer sequestering. Many of these proteins have not been well studied in neuronal growth cones, and whether and how they function in growth cone migration and guidance remains to be seen (Dent et al., 2011). In a minimal model proposed for the actin assembly and disassembly underlying lamellipodial protrusion, just five families of actin-binding proteins were thought to be

needed: WASp, Arp2/3, capping protein, ADF/cofilin, and profilin/β-thymosin (Pollard et al., 2000). Of them, WASp, Arp2/3, and ADF/cofilin have been investigated in nerve growth cones (Dent et al., 2011 and Lowery and Van Vactor, 2009), whereas thymosin/profilin and capping protein have received less attention. Capping barbed ends of actin filaments represents an important mechanism to regulate filament elongation (Pollard and Borisy, 2003). Capping proteins bind to free barbed ends and prevent addition or loss of actin subunits. Of the known actin-capping proteins, the predominant species in most nonmuscle cell types is CapZ (commonly abbreviated as CP). CP is an obligate heterodimer consisting of α and β subunits (Cooper and Sept, 2008 and Schafer, 2004). While both α1 and α2 isoforms are abundant in most tissues (Hart et al.

This overall biased motion click here is likely generated by an intricate particle

kinetics including transient assembly and short rapid vectorial spurts (Figure S4), very different from fast vesicular transport, which is typically persistent. The anterograde bias of the population, the dependence on molecular motors, the dissimilarity of cytosolic cargo motion to untagged PAGFP, the short-range, rapid vectorial speckle movement, and the modeling data all argue that this movement is not entirely a simple diffusive process. In brains, we found that these proteins are also present within high-speed pellet fractions, migrate distinctly from vesicular proteins in density gradients, and are resistant to detergent treatments that solubilize membranes. Finally, our modeling data suggest that clustering of these cytosolic proteins is necessary and sufficient to TAM Receptor inhibitor generate the vectorial shift seen in our imaging experiments. Collectively, the imaging, biochemical, and biophysical data support the following scenario. After synthesis, a small fraction of soluble proteins associate with vesicles and are rapidly

transported (at least for vesicle-associated proteins like synapsins). However, the bulk of soluble proteins transiently assemble into supramolecular assemblies like multiprotein complexes that are conveyed by associations with molecular motors. This association may be direct or indirectly mediated via association with vesicles (note partial overlap of cytosolic cargoes with vesicles in Figures 5B and 5C). We are struck by the peculiarity of this slower motion when compared to other modes of intracellular transport, axonal transport or otherwise. In the classic mode of vesicular transport, for instance, individual vesicles bind to motors and the motor-cargo unit is then transported stochastically for long distances. In the case of cytosolic proteins, however, fluorescent molecules are transported in streaming

plumes, qualitatively distinct from other transport modalities. As cytosolic proteins are ubiquitous, it is tempting to speculate that all cell types employ such mechanisms to convey them to their destinations Tryptophan synthase within the cell. Unlike membranous proteins that are anchored to vesicles, cytosolic proteins invariably have diffusible pools, raising the question of whether diffusion can play a role in cytosolic cargo transport (Miller and Heidemann, 2008). In that regard, recent studies have revealed an intracellular motion where random intracellular agitation from the activity of motors can create cytoplasmic stirring that can then move proteins in its wake (Brangwynne et al., 2008 and Brangwynne et al., 2009).