The time resolution of the Cm measurement is the period of f1, which we varied from 5.12 to 0.32 ms, corresponding to 195 to 3125 Hz. Comparisons between single-sine and dual-sine-wave methods showed no differences for membrane responses to

100 ms depolarizations to −20 mV. Single-sine values of 90 ± 15 fF (n = 12) were obtained as compared to 110 ± 24 fF for dual-sine wave measurements from the same cell population. The same two-sine wave technique (implemented in jClamp) has been used previously, but only as a Kinase Inhibitor Library cell assay before and after measurement which gave similar results to the single-sine method (Edmonds et al., 2004 and Thoreson et al., 2004). Details of methods and control data are presented in Figures S1–S3. The time between stimuli was varied based on the previous stimulus but was never less than 2 min and typically varied between 5 and 10 min to ensure appropriate time for reaching equilibrium. Swept-field confocal high-speed (SFC) calcium Trichostatin A price imaging was performed as previously described (Beurg et al., 2009). The SFC (Prairie Technologies, Middleton WI) was coupled to a Redshirt camera. Fluo 4ff was

used as the indicator, chosen to both limit effects on release properties and serve to localize the calcium source. Images were captured at 125 fps with a 35 mm slit. A 100 × dipping lens with an added 1.25 magnification gave a final pixel size of ∼350 nm. Ribbons were identified by using the Ctbp2 peptide tagged with rhodamine (Zenisek et al., 2003). Data was analyzed by selecting 3 × 3 pixel regions uniformly encompassing Ctbp2-labeled regions. Image planes were selected to help isolate individual synapses to ensure individual already synapses were being investigated. Data were included based on several parameters. Leak currents needed to be less than 50 pA at −85 mV and series resistance (uncompensated) needed to

be stable and below 15 M Ω. As electrode capacitance compensation is critical for the accurate use of the two-sine wave methodology, bath height and electrode filling were kept low to limit stray capacitance. Unless otherwise stated, data are presented as mean ± standard deviation with number of samples (n) given. Where appropriate Student’s t tests, two-tailed, were performed to assess significance; p values and correlation coefficients (r2) are listed with data. Isolated papillae were incubated for 1 hr at 4°C in external solution containing 4% formaldehyde and 0.1% Triton X-100. After washing four times for 10 min at room temperature in external solution containing 0.1% Triton X-100, papillae were incubated for 30 min in the same solution supplemented with 5% bovine serum albumin. Specimens were then incubated with primary antisera diluted at 1:250 to 1:500 in the same solution overnight at 4°C. Antisera included those against Ctbp2 (rabbit polyclonal, #1869), Ribeye (rabbit polyclonal, #1846), and PSD-95 (mouse monoclonal, Abcam #2723, concentrated at 3.

The respiratory chain is a set of biochemically linked multisubunit complexes (complexes

I, II, III, and IV) and two electron carriers (ubiquinone/coenzyme Q and cytochrome c). It uses the energy stored in food to generate a proton gradient across the mitochondrial inner membrane, while at the same time transferring electrons to oxygen, producing water. The energy of the proton gradient this website drives ATP synthesis via ATP synthase (complex V); the ATP is then distributed throughout the cell. The central importance of mitochondria for cellular energy production is underscored by the discovery in the last 20 years of numerous syndromes resulting from OxPhos defects (DiMauro and Schon, 2003). The mitochondrial respiratory chain is the product of a joint effort between

the mitochondrial and nuclear genomes. Mitochondria harbor their own DNA (mtDNA) which is a 16.6 kb double-stranded circular DNA that encodes 13 of the ∼92 polypeptides of the OxPhos system (DiMauro and Schon, 2003), while the nuclear DNA (nDNA) specifies ∼79 OxPhos structural polypeptides and more than 100 other proteins required for the proper incorporation of cofactors (e.g., iron-sulfur proteins, hemes, and copper) and for the assembly of the 3-MA nmr five respiratory chain complexes into an integrated system (Fernández-Vizarra et al., 2009). Patients with OxPhos dysfunction who carry mutations in either mtDNA or nDNA present with a host of clinical features, many of which are neurological, such as seizures, myoclonus, ataxia, progressive muscle weakness, stroke-like episodes, and cognitive impairment (DiMauro and Schon, 2003). However, these manifestations do not typically overlap with either the clinical or the neuropathological hallmarks of any of our selected adult-onset neurodegenerative disorders (Table 1). Furthermore, to a remarkable degree, mutations in both mtDNA and nDNA that affect the integrity or functioning of the OxPhos complexes typically do not strike in adulthood, but rather in infancy (e.g., Leigh

syndrome, which is a fatal, necrotizing encephalopathy). Yet, some patients with OxPhos dysfunction do succumb later, in their twenties or thirties (e.g., via Kearns-Sayre syndrome, which is a sporadically occurring, fatal, multisystem disorder Idoxuridine featuring paralysis of the extraocular muscles, retinal degeneration, and heart block), but it is atypical for mitochondrial patients to survive much longer, and it is exceptional for any individual to experience an onset of an OxPhos disease beyond the age of 40. However, the age at onset and the severity of the disorder correlate well with the degree of ATP deficit caused by the mutation. Thus, “mild” mutations could theoretically give rise to a slowly progressive, late-onset neurodegenerative disease, such as AD or PD.

There are many fewer cell profiles per column, indicating reduced process formation (Figure 3B) and the cells have flattened as confirmed by reduction in the roundness index of cell profiles in vivo (Figure 3C). Flattening

and paucity of processes are also seen even in c-Jun−/− cells from neonatal nerves in vitro ( Figures 3D and 3E). Therefore, this is a robust phenotype that does not depend on long term denervation in vivo. Thus, c-Jun is an cell-intrinsic determinant of Schwann cell morphology check details that controls the structure of the essential regeneration tracks that guide growing axons back to correct targets. c-Jun specification of gene expression and morphology of denervated cells suggested that Schwann cell Dasatinib c-Jun might exert a decisive control over nerve repair. Because survival of injured neurons is the basis for repair, we measured the survival of small and large dorsal root sensory (DRG) neurons following sciatic nerve crush at the sciatic notch. We counted axons in L4 dorsal roots (Coggeshall et al., 1997) and the tibial nerve, and

neuronal somas and nucleoli in DRGs. Comparable results were obtained using all methods. Axon counts in WT dorsal roots showed that 20%–25% of the unmyelinated axons were lost following crush, as expected (Coggeshall et al., 1997). In contrast, 55%–60% of these axons were lost in c-Jun mutants, showing increased death of small DRG neurons in the mutant. This was confirmed by corrected (Abercrombie, 1946) counts of B neuron profiles in DRGs, showing 25%–30% loss in WT but 45%–65% loss in the mutants (Figures 4A and 4B). The number of myelinated

axons in dorsal roots remained unchanged in injured WT mice as expected (Coggeshall et al., 1997). But surprisingly, in the mutants the number of myelinated axons was reduced by 30%–35%, indicating death of large DRG cells. In confirmation, the corrected number of large A cell profiles in DRGs was reduced by about 40% in the mutants. The number of these profiles did not change significantly in injured WT (Figures 4C and 4D). We also carried out counts on DRG sections using nucleoli as the counted entity, an approach that theoretically provides the increased accuracy. Nucleoli in A type DRG neurons from uncut WT (n = 3), 10 week cut WT (n = 3), and 10 week cut c-Jun mutant (n = 3) mice were counted, corrected (Abercrombie, 1946), and expressed as percentage of uncut WT. This showed a 12% reduction in cut WT, (not significant; p > 0.40) but a 50% reduction in the c-Jun mutant (highly significant; p < 0.017). This provides a third line of evidence (in addition to counts of myelinated axons in dorsal roots and cell profiles) for the notion that nerve injury results in the loss of A type DRG neurons in mice that selectively lack c-Jun in Schwann cells.

, 2010). Cortical

specification was suggested by Otx1 expression in approximately half of the cells and by mRNA detection for Foxg1 and Emx1. The differentiated cell population included Ctip2+ neurons; whether other glutamatergic subtypes were also produced was not addressed. The progenitor cell population was a heterogeneous mixture of cell types found throughout the rostrocaudal axis, given that mRNAs for midbrain and posterior CNS markers (En1, Hoxc5, and HB9), were also detected. Compared to the feeder-free telencephalic induction performed by Gaspard et al. (2008), it seems that the FGF2 and/or stromal click here cells may have interfered with the cells’ innate tendency to assume forebrain identity, consistent with the known caudalizing activity of FGF2 (Cox and Hemmati-Brivanlou, 1995, Koch et al., 2009 and Xu et al., 1997). Most intriguingly, however, the cells transplanted Alectinib purchase by Ideguchi et al. into various regions of the mouse cortex eventually extended axons to subcortical targets in a manner appropriate to their cortical site. This

targeting plasticity contrasted with the fixed targeting potential reported by Gaspard et al. (2008), who observed projections typical of visual cortex despite the cells being grafted into the frontal cortex. We will discuss this disparity later in the section on areal plasticity. Importantly, the low-density, adherent protocols for deriving cortical excitatory neurons have not yet been adapted for use with human ESCs or iPSCs. This will be a critical advance if the protocols are to become useful for understanding human cortical development and disease. The ability to study diseases of the cerebral cortex

in vitro and to develop cell-based therapies will below be greatly aided by the ability to produce specific neuronal subtypes from pluripotent stem cells. For example, ALS involves the degeneration of not only motor neurons in the spinal cord but also corticospinal motor neurons (CSMNs) in layer V of the motor cortex. To obtain a pure population of wild-type or disease-background CSMNs from pluripotent cell lines will require several steps: (1) direct pluripotent cells to a telencephalic fate; (2) direct telencephalic cells to a pallial fate; (3) direct pallial cells to the subregional fate of primordial motor cortex; and (4) direct motor cortex precursors to a deep laminar fate to generate and/or purify CSMNs and not other cortical projection neuron subtypes. Here, we review some of the mechanisms that generate various subtypes of cortical neurons from pluripotent stem cells, drawing on developmental studies. Given the default differentiation of pluripotent cells toward anterior neuroectoderm (Kamiya et al., 2011, Muñoz-Sanjuán and Brivanlou, 2002, Smukler et al.

All of these investigations should always be approached with the natural behavior and habitat of the organism in mind. The writing of this review was funded by the Max Planck Society. selleck screening library “
“Voltage-gated ion channels are transmembrane proteins that control and regulate the flow of small ions across cell membranes. They undergo conformational

changes in response to changes in the membrane potential, thereby allowing or blocking the passage of selected ions. Structurally, these channels are formed by four subunits surrounding a central aqueous pore for ion permeation. Each subunit comprises six transmembrane α-helical segments called S1 to S6. The first four α helices, S1–S4, constitute the voltage-sensing domain (VSD). VSDs respond to changes in the membrane potential by moving charged residues across the membrane field. Although there has been much progress over the last decade, atomic details of the voltage-sensing process are not known. Three idealized mechanistic models have been proposed to describe the voltage-sensing motion in voltage-gated K+ (Kv) channels (Tombola et al.,

2005). In the helical-screw/sliding-helix beta-catenin inhibitor model, the S4 segment is assumed to retain its helical conformation as its moves along its long axis (Ahern and Horn, 2004, Ahern and Horn, 2005 and Yarov-Yarovoy et al., 2006). In the transporter-like model, it is assumed that the translational movement of S4 is modest because the membrane field is focused over a small spatial region (Chanda et al., 2005). In the paddle model, the S3-S4 helix-turn-helix is assumed to undergo a fairly large displacement through the Liothyronine Sodium lipids (Jiang et al., 2003 and Ruta et al., 2005). Ultimately, to fully understand the mechanism of voltage activation, one needs knowledge of the three-dimensional structure of a channel in its various functional states. At a minimum, structures of the two main endpoints in

the conformational transitions, the active and resting states, are required to begin to understand voltage sensing. Yet, even for Kv channels, knowledge of those two conformations is currently incomplete. Atomic resolution X-ray structures of the Kv1.2 and the Kv1.2/Kv2.1 chimera channels provide information on the active-state conformation (Long et al., 2005 and Long et al., 2007). The available crystal structures show that the VSD is formed by four antiparallel helices (S1–S4), packed in a counterclockwise fashion as seen from the extracellular side. The first two arginine residues (R1 and R2) along the S4 helix are close to the membrane-solution interface, whereas the following two arginines (R3 and R4) are involved in electrostatic interactions with acidic residues in S2 and S3.

To identify the effects of activation of striatal ChIs on DA transmission, we incorporated the Talazoparib light-activated ion channel channelrhodopsin2 (ChR2) into striatal ChIs of mice. ChR2 expression was restricted to ChIs by injecting an adeno-associated virus (AAV) carrying a Cre-inducible ChR2 gene (fused inframe with the coding sequence for enhanced yellow fluorescent protein [eYFP]) into the striatum of transgenic mice expressing Cre-recombinase under the control of the promoter for choline acetyltransferase (ChAT) (Figure 1A)

(also see Supplemental Information available online). In coronal slices that contain DA axons without DA soma, single blue laser flashes (1–2 ms; 473 nm) of ChR2-expressing terminals (15- to 60-μm-diameter spot) in dorsal or ventral Selleckchem PLX4032 striatum evoked the transient release and reuptake of DA, detected using fast-scan cyclic voltammetry (FCV) at carbon-fiber microelectrodes (see Supplemental Information) (n = 29 animals) (Figure 1B). Extracellular DA concentrations

reached values similar to those evoked by local electrical stimuli (Figure 1B), indicating DA release from a population of axons. Light-evoked DA release was reproducible for several hours (sampling interval ∼2.5 min) and required ACh activation of nAChRs. The β2-nAChR antagonist DHβE abolished DA release (Figure 1C; n = 10, p < 0.001) but not spiking in ChIs (Figure S1E, n = 3) indicating nAChRs postsynaptic to ChIs. ChI-driven DA release did not require muscarinic AChRs (mAChRs, Figure 1D, n = 11), glutamate receptors, or GABA receptors (Figure 1E, n = 9) but was modulated by mechanisms that

normally gate ACh and/or DA exocytosis; it was abolished by Nav+-block by tetrodotoxin (TTX) (n = 10, p < 0.001), zero extracellular Ca2+ (n = 10, p < 0.001), D2 receptor activation with quinpirole, (n = 8, p < 0.001), or mAChR activation with oxotremorine (n = 10, p < 0.001), which limits ACh release from ChIs (Threlfell et al., 2010) (Figure 1E). These observations indicate that endogenous ACh released from ChIs triggers DA all release by activating axonal nAChRs, bypassing action potentials in DA soma. To understand the neuronal events required for ChI-driven DA release, we paired recording of laser-evoked DA using FCV with whole-cell patch-clamp recording of ChR2-expressing, eYFP-tagged ChIs (see Supplemental Information) (Figure 2A). ChR2-expressing ChIs had normal resting membrane potential and TTX-sensitive action potentials (Figure S1; Table S1, n = 11). Laser-evoked DA release was seen after action potentials were evoked in local ChIs (latency 2.0 ± 0.5 ms, Figure 2B, n = 11).

The predominant IGF2BP paralogue described in the context of human cancer is IGF2BP3 (reviewed in: [10]). This is largely due to the fact that the vast majority of studies analyzing IGF2BP expression in cancer rely on one antibody, supplied by DAKO, which is suitable for immuno-histochemical (IHC) analyses. However, Decitabine although proposed to be IGF2BP3-specific, the DAKO-supplied antibody, is not paralogue-specific but recognizes all three IGF2BP paralogues (Fig. 1c). In ovarian carcinoma-derived ES-2 cells, the DAKO-supplied antibody identified endogenous IGF2BP expression but also

detected the expression of all other transiently expressed GFP-tagged IGF2BP paralogues. Notably, this observation is consistent with a previous, independent report by Natkunam et al. [48]. Only few studies use paralogue-specific antibodies, for instance the N-19 antibody supplied by Santa Cruz or the MBL-supplied polyclonal serum directed against a C-terminal peptide of IGF2BP3. These antibodies are highly IGF2BP3-specific and show a negligible cross-reactivity with the other paralogues in Western blotting (Fig. 1c). This is also observed for a monoclonal antibody (6G8) raised by our lab in collaboration with the BSBS antibody facility (Fig. 1c). Hence, the expression of IGF2BPs in cancer has to be considered with great caution in respect to paralogue-specificity.

However, in view of the studies indicating Osimertinib an upregulated expression of IGF2BP1 and IGF2BP3 in various cancers on the basis of RT-PCR or paralogue-specific antibodies and the fact that these both paralogues are barely observed in the adult organism, we

propose that upregulated expression determined by the DAKO-supplied antibody strongly indicates expression of IGF2BP1 and/or IGF2BP3. Bearing in mind the above described limitation, we in the following summarize recent findings on the expression of IGF2BPs in human cancer. Where available, we also indicated a correlation of IGF2BP expression with prognosis and/or metastasis (Table 2). In breast carcinomas, IGF2BP3 Cediranib (AZD2171) expression determined by the DAKO-supplied antibody was observed in the majority of invasive triple-negative mammary carcinomas [49] and [50]. However, in basal-like breast cancer, a significantly upregulated expression was only found in adenoid cystic carcinomas [51] and [52]. IGF2BP3 expression has been reported in all to date analyzed gynecologic cancers including cervical cancer [53], [54] and [55], endometrial cancer [56], [57], [58], [59], [60] and [61] and ovarian cancer [62] and [63]. Consistent with other cancers, IGF2BP3 expression was proposed to be increased in high-grade malignancies, for instance 90% of endometrial clear cell carcinomas [58] and where investigated was associated with an overall poor prognosis, for instance in ovarian carcinomas [62].

The ICC receives innervations from almost all the lower brainstem auditory nuclei, some of which are monaural while others are binaural (Kudo and Nakamura, 1987, Pollak and Casseday, 1989, Helfert and Aschoff, 1997, Casseday et al., 2002, Grothe et al., 2010 and Pollak, 2012). Parsing the unique contribution of each feedforward

circuit to binaural processing in the ICC remains a major challenge. In this study, the revealed monaural-to-binaural spike response transformation and its buy trans-isomer synaptic underpinning may illuminate the principal anatomical determinants of complex signal integration in the ascending projections to the ICC neurons. Here, we propose the most parsimonious explanation for the observed binaural integration of excitatory input, based on the current understanding of auditory brainstem circuits. In all the recorded cells, the binaurally evoke excitatory current was much smaller than the summation of ipsilaterally and contralaterally HDAC inhibitor evoked excitatory currents. In addition, the gain value does not correlate with the strength of ipsilateral

response. These findings directly demonstrate that at least some binaural interactions are shaped within the brainstem and are preserved in the afferent input to the ICC neurons reported here. As reported in previous studies, the superior olivary complex is the first stage to extract detailed information relating interaural time and level differences (Casseday et al., 2002, Kavanagh and Kelly, 1992 and Moore and Caspary, 1983). The fact

that binaurally evoked excitation is weaker than that obtained with contralateral stimulation alone can likely be attributed a fundamental transformation of the afferent signal provided by feedforward inhibition from the medial nucleus of the trapezoid body (MNTB) onto LSO neurons (Cant and Casseday, 1986, Casseday et al., 2002, Moore and Caspary, 1983 and Pollak, 2012). MINTB Chlormezanone inhibition may also be responsible for the nearly complete silencing of ipsilateral excitatory inputs generated by MSO and LSO neurons, thereby scaling down the contralateral excitatory input under binaural stimulation conditions. Thus, the apparent gain modulation of spike responses of ICC neurons may largely reflect a decoding of the binaural computation performed in binaural nuclei prior to the ICC (e.g., LSO). However, it is worth noting that ICC neurons also receive excitatory input from other sources under binaural stimulation, e.g., monaural inputs (both contralateral and ipsilateral; e.g., Li and Pollak, 2013) and the top-down modulatory inputs. Due to these additional inputs, it is possible that ICC neurons can perform additional binaural computation. Compared to excitation, inhibition to most ICC neurons is relatively unchanged by binaural stimulation.

,

2012). The yeast nuclear protein quality control E3 ligase San1 uses a “disorder target misorder” mechanism to recognize different misfolded substrates. San1 contains small segments of conserved sequence that serve as substrate-recognition sites, which are interspersed by intrinsically disordered domains. San1 is endowed with structural plasticity by the flexible disordered regions, find more allowing it to bind differently shaped misfolded substrates (Gardner et al., 2005 and Rosenbaum et al., 2011). We found that EBAX-1 also contains more than one binding site for SAX-3 (Figure S6H), implying that EBAX-1 might use a similar substrate recognition mechanism as San1 to target thermally unstable or disordered SAX-3. In yeast and mammalian ER, an N-glycosylation-mediated

timer paradigm for LGK-974 cost PQC of glycosylated proteins has been reported (Buchberger et al., 2010 and Roth et al., 2010). In this model, successfully N-glycosylated proteins are rapidly folded by chaperones and sorted into the secretory pathway. If unfolded proteins overly dwell in the ER, the ER mannosidase I and ER degradation enhancing alpha-mannosidase-like protein (EDEM) will trim off part of the N-linked glycans from these proteins, thus marking them for the ERAD pathway. Posttranslational modifications can also be used as a strategy to determine the fate of some chaperone/E3 ligase substrates. For example, CHIP degrades the SUMO2/3 protease SENP3 independent of Hsp90 under physiological conditions. Oxidative

stress induces thiol modification at SENP3 cysteine residues that are specifically recognized by Hsp90. This resulting ternary SENP3/CHIP/Hsp90 complex promotes the stabilization of SENP3 instead of degradation (Yan et al., 2010). A number of cochaperones can also regulate the catalytic activity of Hsp70, Hsp90, or CHIP and thus shift the balance between refolding and degradation (Buchberger et al., 2010). Thus, it will be interesting to investigate whether the EBAX-1-type CRL and DAF-21/Hsp90 utilize similar mechanisms to determine the fate of nonnative SAX-3 in vivo. EBAX-1 and its homologs constitute a conserved family of substrate-recognition Thymidine kinase subunits of CRLs. In Drosophila, the EBAX-1 homolog (CG34401) regulates R7 photoreceptor axon targeting (M. Morey, A. Nern, and S.L. Zipursky, personal communication). Mouse and human ZSWIM8 are also widely expressed in the brain (Allen Brain Atlas Resources) ( Lein et al., 2007). Our data show that mouse ZSWIM8 promotes the degradation of a human Robo3(I66L) mutant protein associated with HGPPS. The human homolog ZSWIM8 has been reported to interact with Ataxin 1 and Atrophin 1, two spinocerebellar ataxia-causing proteins ( Lim et al., 2006). It will be of interest to explore the role of EBAX family members in the vertebrate nervous system, both during development and in disease.

, 2008b) with studies of an elementary neural circuit that underlies a simple form of learned fear in Aplysia—sensitization of the gill-withdrawal reflex. A critical component of this reflex that

contributes importantly to the behavior is a direct monosynaptic connection from the siphon sensory neurons to the gill motor neurons. The sensory-to-motor neuron synapse can be reconstituted in dissociated cell culture where it is modulated, as in the intact animal, by serotonin (5-HT), a modulatory transmitter released http://www.selleckchem.com/products/kpt-330.html during the learning of fear ( Marinesco et al., 2006). Five applications of 5-HT over a period of 1.5 hr—designed to simulate five shocks to the tail that produce behavioral sensitization—produce both a long-term learn more increase in the strength of the sensory-to-motor neuron synaptic connection lasting several days (long-term facilitation: LTF, Montarolo et al., 1986) and structural remodeling and growth of new sensory-to-motor neuron synapses ( Glanzman et al., 1990, Bailey

et al., 1992 and Kim et al., 2003). Our recent finding that neurexin and neuroligin are cargo of kinesin transport and are upregulated by 5-HT at the Aplysia sensory-to-motor neuron synapse ( Puthanveettil et al., 2008) further indicates the utility of this model system to study directly the role of the neurexin-neuroligin transsynaptic interaction in learning and memory. We report here that the Aplysia homologs of neurexin (ApNRX) and neuroligin (ApNLG) exhibit strong similarities with their vertebrate counterparts in both domain structure and subcellular localization. Next, we find that depleting

ApNRX in the presynaptic sensory neuron or ApNLG in the postsynaptic motor neuron abolishes both LTF and the associated 5-HT-induced presynaptic structural changes. In addition to their Tryptophan synthase role in the initiation of LTF, we find that ApNRX and ApNLG also play a critical role in the stabilization and persistence of LTF. Finally, we find that overexpression of the ApNLG autism-linked mutant in the postsynaptic motor neuron blocks both intermediate-term and long-term facilitation. We used a primer design strategy for PCR amplification of distantly related gene sequences based on consensus-degenerate hybrid oligonucleotide primers (CODEHOPs, http://blocks.fhcrc.org/codehop.html; Rose et al., 2003) to clone a single Aplysia homolog of neuroligin (ApNLG). Comparison of the deduced amino acid sequence of ApNLG with vertebrate and invertebrate homologs shows that ApNLG shares 39% identities with human neuroligin-3 (NLG-3) ( Figure S1 available online). Despite repeated and rigorous efforts utilizing PCR-based cloning as well as screening cDNA libraries prepared from the Aplysia CNS extracts, we did not find any splice isoforms of ApNLG. The domain structure of ApNLG is similar to vertebrate neuroligins.