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Data de publicació electrònica: 06-04-2023 Transfer RNAs (tRNAs) play a central role in protein translation. Studying them has been difficult in part because a simple method to simultaneously quantify their abundance and chemical modifications is lacking. Here we introduce Nano-tRNAseq, a nanopore-based approach to sequence native tRNA populations that provides quantitative estimates of both tRNA abundances and modification dynamics in a single experiment. We show that default nanopore sequencing settings discard the vast majority of tRNA reads, leading to poor sequencing yields and biased representations of tRNA abundances based on their transcript length. Re-processing of raw nanopore current intensity signals leads to a 12-fold increase in the number of recovered tRNA reads and enables recapitulation of accurate tRNA abundances. We then apply Nano-tRNAseq to Saccharomyces cerevisiae tRNA populations, revealing crosstalks and interdependencies between different tRNA modification types within the same molecule and changes in tRNA populations in response to oxidative stress. We thank all the members of the Novoa laboratory for their valuable insights and discussions. We thank V. Malhotra for providing us with the S. cerevisiae Pus4 KO strains used in this work. We thank the CRG Protein Technologies Unit for producing recombinant E. coli T4 RNA Ligase 2. We thank A. Delgado-Tejedor for help setting up simulations on bulk data from S. cerevisiae Pus1 and Pus7 KO Nano-tRNAseq runs. M.C.L. is supported by an FPI Severo Ochoa fellowship by the Spanish Ministry of Economy, Industry, and Competitiveness (MEIC). L.P.P. is supported by funding from the European Union’s H2020 Research and Innovation Programme under Marie Sklodowska-Curie grant agreement number 754422. I.M. is supported by ‘la Caixa’ InPhINIT PhD fellowship (LCF/BQ/DI18/11660028). This work was supported by funds from the Spanish Ministry of Economy, Industry, and Competitiveness (MEIC) (PID2021-128193NB-100 to E.M.N.). This project has received funding from the ERCEA program (ERC-StG-2021 under grant agreement number 101042103 to E.M.N.). We acknowledge the support of the MEIC to the EMBL partnership, Centro de Excelencia Severo Ochoa and CERCA Programme/Generalitat de Catalunya.

Introduction Parkinson's disease (PD) is a neurodegenerative disease characterized by the deposition of disease-associated α-synuclein, which is thought to follow a sequential distribution in the human brain. Accordingly, α-Synuclein pathology affects the substantia nigra (SN) only in Braak stage 3 out of 6. Moreover, intracellular accumulation of α-synuclein follows maturation from non-ubiquitinated (p62 negative) to ubiquitinated (p62 positive) forms (Lewy bodies). Mitochondrial dysfunction is thought to be a central player in the pathogenesis of PD. It is not clear whether the nigral neurons already show mitochondrial alterations in stages preceding the deposition of α-synuclein in the SN, and how deposition of pre-aggregates or ubiquitinated mature inclusions relate to this. Methods Using cell-based morphometric immunohistochemistry we evaluated the volume density of mitochondrial complex-IV (COX-IV) immunoreactivity in SN neurons lacking or showing α-synuclein deposits in non-diseased individuals and those with Lewy body pathology Braak stage 3 with prominent nigral α-synuclein deposition. Results Increased volume density of COX-IV immunoreactivity appears before detectable pathological α-synuclein in nigral neurons. The volume density decreases significantly as pathological pre-aggregates of α-synuclein accumulates in the neurons and remains at a low level in neurons with p62 positive Lewy bodies. Conclusions COX-IV expression shows a change before and during accumulation of α-synuclein in the SN underpinning the role of early mitochondrio protective therapy strategies in PD.

Nanopore RNA sequencing shows promise as a method for discriminating and identifying different RNA modifications in native RNA. Expanding on the ability of nanopore sequencing to detect N6-methyladenosine, we show that other modifications, in particular pseudouridine (Ψ) and 2'-O-methylation (Nm), also result in characteristic base-calling 'error' signatures in the nanopore data. Focusing on Ψ modification sites, we detected known and uncovered previously unreported Ψ sites in mRNAs, non-coding RNAs and rRNAs, including a Pus4-dependent Ψ modification in yeast mitochondrial rRNA. To explore the dynamics of pseudouridylation, we treated yeast cells with oxidative, cold and heat stresses and detected heat-sensitive Ψ-modified sites in small nuclear RNAs, small nucleolar RNAs and mRNAs. Finally, we developed a software, nanoRMS, that estimates per-site modification stoichiometries by identifying single-molecule reads with altered current intensity and trace profiles. This work demonstrates that Nm and Ψ RNA modifications can be detected in cellular RNAs and that their modification stoichiometry can be quantified by nanopore sequencing of native RNA. This project has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under Marie Skodowska-Curie grant agreement no. 713673. This work was supported by the Australian Research Council (DP180103571 to E.M.N.) and the MEIC (PGC2018-098152-A-100 to E.M.N.). We acknowledge the support of the MEIC to the EMBL partnership, the Centro de Excelencia Severo Ochoa and the CERCA Programme/Generalitat de Catalunya.

Purinergic P2 receptors, activated by endogenous ATP, are prominently expressed on neuronal and non-neuronal cells during development of the auditory periphery and central auditory neurons. In the mature cochlea, extracellular ATP contributes to ion homeostasis, and has a protective function against noise exposure. Here, we focus on the modulation of activity by extracellular ATP during early postnatal development of the lower auditory pathway. In mammals, spontaneous patterned activity is conveyed along afferent auditory pathways before the onset of acoustically evoked signal processing. During this critical developmental period, inner hair cells fire bursts of action potentials that are believed to provide a developmental code for synaptic maturation and refinement of auditory circuits, thereby establishing a precise tonotopic organization. Endogenous ATP-release triggers such patterned activity by raising the extracellular K(+) concentration and contributes to firing by increasing the excitability of auditory nerve fibers, spiral ganglion neurons, and specific neuron types within the auditory brainstem, through the activation of diverse P2 receptors. We review recent studies that provide new models on the contribution of purinergic signaling to early development of the afferent auditory pathway. Further, we discuss potential future directions of purinergic research in the auditory system.

Das auditive System setzt sich aus dem in der Peripherie gelegenen Ohr, in dem eine Umwandlung des Schalls in ein elektrisches Signal stattfindet, und Neuronen, die anhand von Aktionspotenzialen eine zentrale Verarbeitung durchfuhren, zusammen. Die wichtigsten anatomischen und funktionellen Merkmale des auditiven Systems werden erlautert. Dazu fand eine selektive Literaturrecherche in den Datenbanken PubMed (auch in der Europe PubMed Central), Psychline, Google Scholar, Cochrane Library und Web of Science statt, und zusatzliche Angaben einschlagiger Werke bzw. Websites auf den Gebieten (Neuro‑)Anatomie, (Neuro‑)Physiologie und (Neuro‑)Otologie, u. a. mit den Suchbegriffen Horbahn, „auditory system“, „auditory pathway“, „receptors“, „spatial hearing“, „auditory cognition“ wurden mit einbezogen.

Menschen nehmen Informationen aus ihrem Umfeld zum grosten Teil uber das visuelle System auf. Dabei werden Signale von den Photorezeptoren der Retina uber Bipolar- und Ganglienzellen auf spezifische neuronale Subpopulationen im Corpus geniculatum laterale projiziert und von dort aus in zugeordnete Schichten des primaren visuellen Kortex weitergeleitet. Die wichtigsten anatomischen und funktionellen Merkmale des visuellen Systems werden beleuchtet. Dazu fand eine selektive Literaturrecherche in den Datenbanken PubMed (auch in der Europe PubMed Central), Psychline, Google Scholar, Cochrane Library und Web of Science statt, und es wurden zusatzliche Angaben einschlagiger Werke bzw. Websites auf den Gebieten (Neuro‑)Anatomie, (Neuro‑)Physiologie und (Neuro‑)Otologie u. a. mit den Suchbegriffen Sehbahn, „visual system“, „visual pathway“, „receptors“, „spatial cognition“, „visual cognition“ einbezogen.

The existence of naturally occurring ribosome heterogeneity is now a well-acknowledged phenomenon. However, whether this heterogeneity leads to functionally diverse ‘specialized ribosomes’ is still a controversial topic. Here, we explore the biological function of RPL3L (uL3L), a ribosomal protein (RP) paralog of RPL3 (uL3) that is exclusively expressed in muscle and heart tissues, by generating a viable homozygousRpl3lknockout mouse strain. We identify a rescue mechanism in which, upon RPL3L depletion, RPL3 becomes upregulated, yielding RPL3-containing ribosomes instead of RPL3L-containing ribosomes that are typically found in cardiomyocytes. Using both ribosome profiling (Ribo-Seq) and a novel orthogonal approach consisting of ribosome pulldown coupled to nanopore sequencing (Nano-TRAP), we find that RPL3L neither modulates translational efficiency nor ribosome affinity towards a specific subset of transcripts. By contrast, we show that depletion of RPL3L leads to increased ribosome-mitochondria interactions in cardiomyocytes, which is accompanied by a significant increase in ATP levels, potentially as a result of mitochondrial activity fine-tuning. Our results demonstrate that the existence of tissue-specific RP paralogs does not necessarily lead to enhanced translation of specific transcripts or modulation of translational output. Instead, we reveal a complex cellular scenario in which RPL3L modulates the expression of RPL3, which in turn affects ribosomal subcellular localization and, ultimately, mitochondrial activity.

ObjectiveAnti-IgLON5 disease forms an interface between neuroinflammation and neurodegeneration and includes clinical phenotypes that are often similar to those of neurodegenerative diseases. An early diagnosis of patients with anti-IgLON5 disease and differentiation from neurodegenerative diseases is necessary and may have therapeutic implications.MethodsIn our small sample size study we investigated oculomotor function as a differentiating factor between anti-IgLON5 disease and neurodegenerative disorders. We examined ocular motor and vestibular function in four patients suffering from anti-IgLON5 disease using video-oculography (VOG) and a computer-controlled rotational chair system (sampling rate 60 Hz) and compared the data with those from ten age-matched patients suffering from progressive supranuclear palsy (PSP) and healthy controls (CON).ResultsPatients suffering from anti-IgLON5 disease differed from PSP most strikingly in terms of saccade velocity and accuracy, the presence of square wave jerks (SWJ) (anti-IgLON5 0/4 vs. PSP 9/10) and the clinical finding of supranuclear gaze palsy (anti-IgLON5 1/4). The presence of nystagmus, analysis of smooth pursuit eye movements, VOR and VOR suppression was reliable to differentiate between the two disease entities. Clear differences in all parameters, although not always significant, were found between all patients and CON.DiscussionWe conclude that the use of VOG as a tool for clinical neurophysiological assessment can be helpful in differentiating between patients with PSP and patients with anti-IgLON5 disease. VOG could have particular value in patients with suspected PSP and lack of typical Parkinson’s characteristics. future trials are indispensable to assess the potential of oculomotor function as a biomarker in anti-IgLON5 disease.

Mutations in GBA, which encodes the lysosomal enzyme glucocerebrosidase, are the highest genetic risk factor for Parkinson's disease (PD), although the mechanistic link between GBA mutations and PD is unknown. An attractive hypothesis is that the lipid substrate of glucocerebrosidase, glucosylceramide, accumulates in patients with PD with a GBA mutation (PD-GBA). Despite the availability of new and accurate methods to quantitatively measure brain glucosylceramide levels, there is little evidence that glucosylceramide, or its deacetylated derivative, glucosylsphingosine, accumulates in human PD or PD-GBA brain or cerebrospinal fluid. Thus, a straightforward association between glucosylceramide levels and the development of PD does not appear valid, necessitating the involvement of other cellular pathways to explain this association, which could involve defects in lysosomal function.

Purely torsional spontaneous nystagmus almost always has a central vestibular cause. We describe a man with spontaneous pulse-synchronous torsional nystagmus in which the clockwise component corresponded to his pulse upswing, in keeping with a peripheral vestibular cause; following imaging we diagnosed left-sided superior canal dehiscence syndrome. Identifying pulse synchronicity of spontaneous nystagmus may help to distinguish central from peripheral vestibular torsional nystagmus, and is readily confirmed at the bedside using Frenzel’s glasses and a pulse oximeter.

The amygdala has long been implicated in the pathophysiology of human temporal lobe epilepsy (TLE). The different nuclei of this complex structure are interconnected and share reciprocal connections with the hippocampus and other brain structures, partly via the entorhinal cortex. Expression of GABAA receptor subunits α1, α2, α3, α5, β2, β2/3, and γ2 was evaluated by immunohistochemistry in amygdala specimens and the entorhinal cortex of 12 TLE patients and 12 autopsy controls. A substantial decrease in the expression of α1, α2, α3, and β2/3 subunits was found in TLE cases, accompanied by an increase of γ2 subunit expression in many nuclei. In the entorhinal cortex, the expression of all GABAA receptor subunits was decreased except for the α1 subunit, which was increased on cellular somata. The overall reduction in α subunit expression may lead to decreased sensitivity to GABA and its ligands and compromise phasic inhibition, whereas upregulation of the γ2 subunit might influence clustering and kinetics of receptors and impair tonic inhibition. The description of these alterations in the human amygdala is important for the understanding of network changes in TLE as well as the development of subunit-specific therapeutic agents for the treatment of this disease.

Numerous studies indicate that deficits in the proper integration or migration of specific GABAergic precursor cells from the subpallium to the cortex can lead to severe cognitive dysfunctions and neurodevelopmental pathogenesis linked to intellectual disabilities. A different set of GABAergic precursors cells that express Pax2 migrate to hindbrain regions, targeting, for example auditory or somatosensory brainstem regions. We demonstrate that the absence of BDNF in Pax2-lineage descendants of BdnfPax2KOs causes severe cognitive disabilities. In BdnfPax2KOs, a normal number of parvalbumin-positive interneurons (PV-INs) was found in the auditory cortex (AC) and hippocampal regions, which went hand in hand with reduced PV-labeling in neuropil domains and elevated activity-regulated cytoskeleton-associated protein (Arc/Arg3.1; here: Arc) levels in pyramidal neurons in these same regions. This immaturity in the inhibitory/excitatory balance of the AC and hippocampus was accompanied by elevated LTP, reduced (sound-induced) LTP/LTD adjustment, impaired learning, elevated anxiety, and deficits in social behavior, overall representing an autistic-like phenotype. Reduced tonic inhibitory strength and elevated spontaneous firing rates in dorsal cochlear nucleus (DCN) brainstem neurons in otherwise nearly normal hearing BdnfPax2KOs suggests that diminished fine-grained auditory-specific brainstem activity has hampered activity-driven integration of inhibitory networks of the AC in functional (hippocampal) circuits. This leads to an inability to scale hippocampal post-synapses during LTP/LTD plasticity. BDNF in Pax2-lineage descendants in lower brain regions should thus be considered as a novel candidate for contributing to the development of brain disorders, including autism.

Variants in CSDE1, a gene encoding a constrained RNA-binding protein, have recently been associated with a spectrum of neurodevelopmental conditions encompassing autism, seizures and ocular abnormalities. According to previously reported individuals, pathogenic variants in CSDE1 are typically associated with developmental delay and intellectual disability. Here, we report one individual with normal neurodevelopment and adult-onset neuropsychiatric features (i.e., acute psychosis) due to the novel de novo truncating variant c.2272C>T, p.(Gln758*) in CSDE1 (NM_001242891.1). Neuropsychological assessment confirmed deficits regarding verbal fluency, semantic memory, executive function and processing speed. Overall, our findings expand the phenotypic spectrum of CSDE1-related disorder towards the mild end.

Nanopore RNA sequencing shows promise as a method for discriminating and identifying different RNA modifications in native RNA. Expanding on the ability of nanopore sequencing to detect N

A broad diversity of modifications decorate RNA molecules. Originally conceived as static components, evidence is accumulating that some RNA modifications may be dynamic, contributing to cellular responses to external signals and environmental circumstances. A major difficulty in studying these modifications, however, is the need of tailored protocols to map each modification type individually. Here, we present a new approach that uses direct RNA nanopore sequencing to identify and quantify RNA modifications present in native RNA molecules. First, we show that each RNA modification type results in a distinct and characteristic base-calling ‘error’ signature, which we validate using a battery of genetic strains lacking either pseudouridine (Y) or 2’-O-methylation (Nm) modifications. We then demonstrate the value of these signatures forde novoprediction of Y modifications transcriptome-wide, confirming known Y-modified sites as well as uncovering novel Y sites in mRNAs, ncRNAs and rRNAs, including a previously unreported Pus4-dependent Y modification in yeast mitochondrial rRNA, which we validate using orthogonal methods. To explore the dynamics of pseudouridylation across environmental stresses, we treat the cells with oxidative, cold and heat stresses, finding that yeast ribosomal rRNA modifications do not change upon environmental exposures, contrary to the general belief. By contrast, our method reveals many novel heat-sensitive Y-modified sites in snRNAs, snoRNAs and mRNAs, in addition to recovering previously reported sites. Finally, we develop a novel software,nanoRMS, which we show can estimate per-site modification stoichiometries from individual RNA molecules by identifying the reads with altered current intensity and trace profiles, and quantify the RNA modification stoichiometry changes between two conditions. Our work demonstrates that Y RNA modifications can be predictedde novoand in a quantitative manner using native RNA nanopore sequencing.

The main cerebellar structures involved in ocular motor control comprise the flocculus and paraflocculus, nodulus and uvula, as well as the oculomotor vermis (OMV) and the fastigial oculomotor region (FOR).1 Although the flocculus and paraflocculus are critical for smooth pursuit and for gaze holding,2 the so-called “vestibulocerebellar” centers, the OMV and the FOR are exclusively involved in the control of smooth pursuit and saccades.

Humans receive information from their environment via the visual and auditory systems. This information protects us from dangers and guarantees vital actions, such as social interaction, locomotion, work processes and nutrition. The most important anatomical and functional features of these two sensory systems are compared and elucidated with respect to their interaction/functional complementarity. For this purpose, a selective literature search was carried out in the databases PubMed (also in the Europe PubMed Central), Psychline, Google Scholar, Cochrane Library and Web of Science. Additional information was obtained from relevant books and websites in the fields of (neuro)anatomy, (neuro)physiology, (neuro)ophthalmology and (neuro)otology. Search terms were Hörbahn, Sehbahn, visual system, auditory system, visual pathway, auditory pathway, receptors, spatial hearing, spatial cognition, auditory cognition and visual cognition.

The auditory system consists of the ear located in the periphery, in which a conversion of the sound into an electrical signal takes place, and neurons, which perform central processing based on action potentials. The most important anatomical and functional features of the auditory system are explained. For this purpose, a selective literature search was carried out in the databases PubMed (also in the Europe PubMed Central), Psychline, Google Scholar, Cochrane Library and Web of Science. Additional information was obtained from relevant books or websites in the fields of (neuro)anatomy, (neuro)physiology, (neuro)ophthalmology and (neuro)otology, among others with the keywords Hörbahn, auditory system, auditory pathway, receptors, spatial hearing and auditory cognition.

Humans receive information from their environment mainly via the visual system. Signals from the photoreceptors of the retina via bipolar and ganglion cells are projected onto specific neuronal subpopulations in the lateral geniculate body and from there are forwarded to appropriate layers of the primary visual cortex. The most important anatomical and functional features of the visual system are explained. For this purpose, a selective literature search was carried out in the databases PubMed (also in Europe PubMed Central), Psychline, Google Scholar, Cochrane Library and Web of Science as well as additional information in relevant books or websites in the fields of (neuro)anatomy, (neuro)physiology, (neuro)ophthalmology and (neuro)otology, among others with the search terms Sehbahn, visual system, visual pathway, receptors, spatial cognition and visual cognition.

Summary Background Dystonia is a clinically and genetically heterogeneous condition that occurs in isolation (isolated dystonia), in combination with other movement disorders (combined dystonia), or in the context of multisymptomatic phenotypes (isolated or combined dystonia with other neurological involvement). However, our understanding of its aetiology is still incomplete. We aimed to elucidate the monogenic causes for the major clinical categories of dystonia. Methods For this exome-wide sequencing study, study participants were identified at 33 movement-disorder and neuropaediatric specialty centres in Austria, Czech Republic, France, Germany, Poland, Slovakia, and Switzerland. Each individual with dystonia was diagnosed in accordance with the dystonia consensus definition. Index cases were eligible for this study if they had no previous genetic diagnosis and no indication of an acquired cause of their illness. The second criterion was not applied to a subset of participants with a working clinical diagnosis of dystonic cerebral palsy. Genomic DNA was extracted from blood of participants and whole-exome sequenced. To find causative variants in known disorder-associated genes, all variants were filtered, and unreported variants were classified according to American College of Medical Genetics and Genomics guidelines. All considered variants were reviewed in expert round-table sessions to validate their clinical significance. Variants that survived filtering and interpretation procedures were defined as diagnostic variants. In the cases that went undiagnosed, candidate dystonia-causing genes were prioritised in a stepwise workflow. Findings We sequenced the exomes of 764 individuals with dystonia and 346 healthy parents who were recruited between June 1, 2015, and July 31, 2019. We identified causative or probable causative variants in 135 (19%) of 728 families, involving 78 distinct monogenic disorders. We observed a larger proportion of individuals with diagnostic variants in those with dystonia (either isolated or combined) with coexisting non-movement disorder-related neurological symptoms (100 [45%] of 222; excepting cases with evidence of perinatal brain injury) than in those with combined (19 [19%] of 98) or isolated (16 [4%] of 388) dystonia. Across all categories of dystonia, 104 (65%) of the 160 detected variants affected genes which are associated with neurodevelopmental disorders. We found diagnostic variants in 11 genes not previously linked to dystonia, and propose a predictive clinical score that could guide the implementation of exome sequencing in routine diagnostics. In cases without perinatal sentinel events, genomic alterations contributed substantively to the diagnosis of dystonic cerebral palsy. In 15 families, we delineated 12 candidate genes. These include IMPDH2, encoding a key purine biosynthetic enzyme, for which robust evidence existed for its involvement in a neurodevelopmental disorder with dystonia. We identified six variants in IMPDH2, collected from four independent cohorts, that were predicted to be deleterious de-novo variants and expected to result in deregulation of purine metabolism. Interpretation In this study, we have determined the role of monogenic variants across the range of dystonic disorders, providing guidance for the introduction of personalised care strategies and fostering follow-up pathophysiological explorations. Funding Else Kroner-Fresenius-Stiftung, Technische Universitat Munchen, Helmholtz Zentrum Munchen, Medizinische Universitat Innsbruck, Charles University in Prague, Czech Ministry of Education, the Slovak Grant and Development Agency, the Slovak Research and Grant Agency.

Background and purpose Next-generation sequencing has greatly improved the diagnostic success rates for genetic neuromuscular disorders (NMDs). Nevertheless, most patients still remain undiagnosed, and there is a need to maximize the diagnostic yield. Methods A retrospective study was conducted on 72 patients with NMDs who underwent exome sequencing (ES), partly followed by genotype-guided diagnostic reassessment and secondary investigations. The diagnostic yields that would have been achieved by appropriately chosen narrow and comprehensive gene panels were also analysed. Results The initial diagnostic yield of ES was 30.6% (n = 22/72 patients). In an additional 15.3% of patients (n = 11/72) ES results were of unknown clinical significance. After genotype-guided diagnostic reassessment and complementary investigations, the yield was increased to 37.5% (n = 27/72). Compared to ES, targeted gene panels (

We present a family with two members affected by hyperekplexia and two unaffected members. All exons in the glycine receptor alpha 1 subunit gene (GLRA1) were sequenced in all four family members. Our index patient harbored a novel nonsense mutation (p.Trp314*; rs867618642) in the transmembrane domain three of the GLRA1 and a novel missense variant in the NH2-terminal part (p.Val67Met; rs142888296). After development of tolerance for the effective treatment with clobazam a drug holiday led to a sustained restoration of the treatment response.

What a state would be like - strong or weak, solid or prone to collapse - depends on the manner in which it begins. Likewise, once a state is constituted, a periodical return to the beginning seems to be a remedy against the deterioration of an order. For Machiavelli, however, beginning not only isn?t a self-explanatory notion, but has multiple meaning and is, moreover, paradoxical. Considering primarily two Machiavelli?s main works, The Prince and Discourses on Livi, this article tends to point out different beginnings in Machiavelli?s opus (beginning in time and beginning out of time, beginning of history and beginning of writing, beginning of monarchy and beginning of republic), as well as the constitutive instability of the beginning (what or who establishes the beginning: the mind, the ruler, a random event, a foundational gesture or an outcome?).

While the consumption of caffeine and cocoa has been associated with a variety of health benefits to humans, some authors have proposed that excessive caffeine intake may increase the frequency of epileptic seizures in humans and reduce the efficiency of antiepileptic drugs. Little is known, however, about the proconvulsant potential of the sustained, excessive intake of cocoa on hippocampal neural circuits. Using the mouse as an experimental model, we examined the effects of the chronic consumption of food enriched in cocoa-based dark chocolate on motor and mood-related behaviours as well as on the excitability properties of hippocampal neurons. Cocoa food enrichment did not affect body weights or mood-related behaviours but rather promoted general locomotion and improved motor coordination. However, ex vivo electrophysiological analysis revealed a significant enhancement in seizure-like population spike bursting at the neurogenic dentate gyrus, which was paralleled by a significant reduction in the levels of GABA-α1 receptors thus suggesting that an excessive dietary intake of cocoa-enriched food might alter some of the synaptic elements involved in epileptogenesis. These data invite further multidisciplinary research aiming to elucidate the potential deleterious effects of chocolate abuse on behaviour and brain hyperexcitability.

GABAergic neurotransmission in the amygdala contributes to the regulation of emotional processes in anxiety, stress, reward, mnestic functions, addiction, and epilepsy. Species-specific differences in the distribution and composition of GABAA receptors may account for distinct effects and side-effects of GABAergic agents. However, data on the distribution and composition of GABAA receptors in the human amygdala are lacking. Here, the expression of GABAA receptor subunits α1, α2, α3, α5, β2, β2/3, and γ2 was studied in the human amygdala using immunohistochemistry. Hippocampi were evaluated as a reference structure. Neuronal counts and field fraction analyses were performed, and subcellular expression of GABAA receptor subunits was analyzed semiquantitatively. In the amygdala, field fraction analyses showed the highest α1 expression in the lateral nucleus (La), whereas α3 was prominent in intercalated nuclei (IC), and α5 and γ2 in the cortical nuclei, and amygdalo-hippocampal/parahippocampal-amygdala transition areas. In the hippocampus, α1 and α3 were accentuated in the dentate gyrus, CA1 region, and subiculum, whereas α5 expression was rather uniform. In both regions, α2 was homogenously distributed, and the two β subunits and γ2 showed faint immunostaining. The intensity of subunit expression also varied in the neuropil, neuronal somata, and/or cellular processes in the subregions. GABAA receptors containing subunit α1, showing the strongest expression in the La, and α3, with the strongest expression in the IC and subiculum, could be targets for treating amygdala-related disorders. Differences in GABAA receptor subunit expression between the human and rodent amygdala should be taken into consideration when developing subunit-selective drugs.

Dopamine receptors 1 and 2 (DRD1, DRD2) are essential for signaling in the brain for a multitude of brain functions. Previous work using several antibodies against these receptors is abundant but only the minority of antibodies used have been validated and, therefore, the results of these studies remain uncertain. Herein, antibodies against DRD1 (Merck Millipore AB1765P, Santa Cruz Biotechnology sc-14001, Sigma Aldrich D2944, Alomone Labs ADR-001) and DRD2 (Abcam ab21218, Merck Millipore AB5084P, Santa Cruz Biotechnology sc-5303) have been tested using western blotting and immunohistochemistry on mouse striatum (wild type and corresponding knock-out mice) and when specific, they were further evaluated on rat and human striatum. Moreover, a DRD1 antibody and a DRD2 antibody that were found specific in our tests were used for immunoprecipitation with subsequent mass spectrometrical identification of the immunoprecipitate. Two out of nine antibodies (anti DRD1 Sigma Aldrich D2944 and anti DRD2 Merck Millipore AB5084P) against the abovementioned dopamine receptors were specific for DRD1 and DRD2 as evaluated by western blotting and immunohistochemistry and the immunoprecipitate indeed contained DRD1 and DRD2 as revealed by mass spectrometry. The observed findings may question the use of so far non-validated antibodies against the abovementioned dopamine receptors. Own observations may be valuable for the interpretation of previous results and the design of future studies using dopamine receptors DRD1 or DRD2.

Synaptic refinement and strengthening are activity dependent processes that establish orderly arranged cochleotopic maps throughout the central auditory system. The maturation of auditory brainstem circuits is guided by action potentials (APs) arising from the inner hair cells in the developing cochlea. The AP firing of developing central auditory neurons can be modulated by paracrine ATP signaling, as shown for the cochlear nucleus bushy cells and principal neurons in the medial nucleus of the trapezoid body. However, it is not clear whether neuronal activity may be specifically regulated with respect to the nuclear tonotopic position, i.e. sound frequency selectivity. Using slice recordings before hearing onset and in vivo recordings with iontophoretic drug applications after hearing onset we show that cell-specific purinergic modulation follows a precise tonotopic pattern in the ventral cochlear nucleus of developing gerbils. In high-frequency regions, ATP responsiveness diminished before hearing onset. In low-to-mid frequency regions, ATP modulation persisted after hearing onset in a subset of low-frequency bushy cells (CF

Rapid anti-suicidal and antidepressant effects of ketamine have repeatedly been confirmed in unipolar and bipolar depression. Although meaningful antidepressant efficacy of ketamine has also been shown in depressed patients with a history of psychotic symptoms, its administration in psychotic disorders has largely been neglected due to its potential to exacerbate dissociative or psychotic symptoms. Presenting a case of a young female inpatient suffering from schizophrenia with a severe post-psychotic depression, we demonstrate a robust anti-suicidal and antidepressant effect of S-ketamine infusions administered thrice weekly for 3 weeks in total. Importantly, no relevant psychotic or dissociative symptoms occurred during the whole augmentation treatment period leading to a sustained remission of depressive symptoms and suicidality. Our safe and effective experience with intravenous S-ketamine might encourage researchers and clinicians to widen its administration range beyond the diagnosis of depression to enrich the current knowledge of ketamine effects in psychotic disorders.

ATP1A3 related disease is a clinically heterogeneous condition currently classified as alternating hemiplegia of childhood, rapid-onset dystonia-parkinsonism and cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss. Recently, it has become apparent that a remarkably large subgroup is suffering from often difficult-to-treat epilepsy. The aim of the present study was to assess the prevalence and efficacy of commonly used anti-epileptic-drugs (AEDs) in patients with ATP1A3 related seizures. Therefore, we performed a retrospective study of patients in combination with a systematic literature-based review. Inclusion criteria were: verified ATP1A3 mutation, seizures and information about AED treatment. The literature review yielded records for 188 epileptic ATP1A3 patients. For 14/188 cases, information about anti-epileptic treatment was available. Combined with seven unpublished records of ATP1A3 patients, a sample size of 21 patients was reached. Most used AED were levetiracetam (n = 9), phenobarbital (n = 8), valproic acid (n = 7), and topiramate (n = 5). Seizure reduction was reported for 57% of patients (n = 12). No individual AEDs used (either alone or combined) had a success rate over 50%. There was no significant difference in the response rate between various AEDs. Ketogenic diet was effective in 2/4 patients. 43% of patients (n = 9) did not show any seizure relief. Even though Epilepsy is a significant clinical issue in ATP1A3 patients, only a minority of publications provide any information about patients’ anti-epileptic treatment. The findings of treatment effectiveness in only 57% (or lower) of patients, and the non-existence of a clear first-line AED in ATP1A3 related epilepsy stresses the need for further research.

Associative learning is thought to involve different forms of activity-dependent synaptic plasticity. Although previous studies have mostly focused on learning-related changes occurring at excitatory glutamatergic synapses, we found that associative learning, such as fear conditioning, also entails long-lasting functional and structural plasticity of GABAergic synapses onto pyramidal neurons of the murine basal amygdala. Fear conditioning-mediated structural remodeling of GABAergic synapses was associated with a change in mIPSC kinetics and an increase in the fraction of synaptic benzodiazepine-sensitive (BZD) GABAA receptors containing the α2 subunit without altering the intrasynaptic distribution and overall amount of BZD-GABAA receptors. These structural and functional synaptic changes were partly reversed by extinction training. These findings provide evidence that associative learning, such as Pavlovian fear conditioning and extinction, sculpts inhibitory synapses to regulate inhibition of active neuronal networks, a process that may tune amygdala circuit responses to threats.