Distinct Regulation of Dopamine D3 Receptor in the Basolateral Amygdala and Dentate Gyrus during the Reinstatement of Cocaine CPP Induced by Drug Priming and Social Stress.

Relapse in the seeking and intake of cocaine is one of the main challenges when treating its addiction. Among the triggering factors for the recurrence of cocaine use are the re-exposure to the drug and stressful events. Cocaine relapse engages the activity of memory-related nuclei, such as the basolateral amygdala (BLA) and the hippocampal dentate gyrus (DG), which are responsible for emotional and episodic memories. Moreover, D3 receptor (D3R) antagonists have recently arisen as a potential treatment for preventing drug relapse. Thus, we have assessed the impact of D3R blockade in the expression of some dopaminergic markers and the activity of the mTOR pathway, which is modulated by D3R, in the BLA and DG during the reinstatement of cocaine-induced conditioned place preference (CPP) evoked by drug priming and social stress. Reinstatement of cocaine CPP paralleled an increasing trend in D3R and dopamine transporter (DAT) levels in the BLA. Social stress, but not drug-induced reactivation of cocaine memories, was prevented by systemic administration of SB-277011-A (a selective D3R antagonist), which was able, however, to impede D3R and DAT up-regulation in the BLA during CPP reinstatement evoked by both stress and cocaine. Concomitant with cocaine CPP reactivation, a diminution in mTOR phosphorylation (activation) in the BLA and DG occurred, which was inhibited by D3R blockade in both nuclei before the social stress episode and only in the BLA when CPP reinstatement was provoked by a cocaine prime. Our data, while supporting a main role for D3R signalling in the BLA in the reactivation of cocaine memories evoked by social stress, indicate that different neural circuits and signalling mechanisms might mediate in the reinstatement of cocaine-seeking behaviours depending upon the triggering stimuli.

miR-132/212 deficiency impairs tau metabolism and promotes pathological aggregation in vivo.

Alzheimer's disease (AD) and related tauopathies comprise a large group of neurodegenerative diseases associated with the pathological aggregation of tau protein. While much effort has focused on understanding the function of tau, little is known about the endogenous mechanisms regulating tau metabolism in vivo and how these contribute to disease. Previously, we have shown that the microRNA (miRNA) cluster miR-132/212 is downregulated in tauopathies such as AD. Here, we report that miR-132/212 deficiency in mice leads to increased tau expression, phosphorylation and aggregation. Using reporter assays and cell-based studies, we demonstrate that miR-132 directly targets tau mRNA to regulate its expression. We identified GSK-3ß and PP2B as effectors of abnormal tau phosphorylation in vivo. Deletion of miR-132/212 induced tau aggregation in mice expressing endogenous or human mutant tau, an effect associated with autophagy dysfunction. Conversely, treatment of AD mice with miR-132 mimics restored in part memory function and tau metabolism. Finally, miR-132 and miR-212 levels correlated with insoluble tau and cognitive impairment in humans. These findings support a role for miR-132/212 in the regulation of tau pathology in mice and humans and provide new alternatives for therapeutic development.

Cholesterol 24-hydroxylase defect is implicated in memory impairments associated with Alzheimer-like Tau pathology.

Alzheimer's disease (AD) is characterized by both amyloid and Tau pathologies. The amyloid component and altered cholesterol metabolism are closely linked, but the relationship between Tau pathology and cholesterol is currently unclear. Brain cholesterol is synthesized in situ and cannot cross the blood-brain barrier: to be exported from the central nervous system into the blood circuit, excess cholesterol must be converted to 24S-hydroxycholesterol by the cholesterol 24-hydroxylase encoded by the CYP46A1 gene. In AD patients, the concentration of 24S-hydroxycholesterol in the plasma and the cerebrospinal fluid are lower than in healthy controls. The THY-Tau22 mouse is a model of AD-like Tau pathology without amyloid pathology. We used this model to investigate the potential association between Tau pathology and CYP46A1 modulation. The amounts of CYP46A1 and 24S-hydroxycholesterol in the hippocampus were lower in THY-Tau22 than control mice. We used an adeno-associated virus (AAV) gene transfer strategy to increase CYP46A1 expression in order to investigate the consequences on THY-Tau22 mouse phenotype. Injection of the AAV-CYP46A1 vector into the hippocampus of THY-Tau22 mice led to CYP46A1 and 24S-hydroxycholesterol content normalization. The cognitive deficits, impaired long-term depression and spine defects that characterize the THY-Tau22 model were completely rescued, whereas Tau hyperphosphorylation and associated gliosis were unaffected. These results argue for a causal link between CYP46A1 protein content and memory impairments that result from Tau pathology. Therefore, CYP46A1 may be a relevant therapeutic target for Tauopathies and especially for AD.

Defining the human sperm microtubulome: an integrated genomics approach.

Sperm motility notably depends on the structural integrity of the flagellum and the regulation of microtubule dynamics. Although researchers have started to use "omics" techniques to characterize the human sperm's molecular landscape, the constituents responsible for the assembly, organization, and dynamics of the flagellum microtubule have yet to be fully defined. In this study, we defined a core set of 116 gene products associated with the human sperm microtubulome (including products potentially involved in abnormal ciliary phenotypes and male infertility disorders). To this end, we designed and applied an integrated genomics workflow and combined relevant proteomics, transcriptomics, and interactomics datasets to reconstruct a dynamic interactome map. By further integrating phenotypic information, we defined a disease-interaction network; this enabled us to highlight a number of novel factors potentially associated with altered sperm motility and male fertility. Lastly, we experimentally validated the expression pattern of two candidate genes (CUL3 and DCDC2C) that had never previously been associated with male germline differentiation. Our analysis suggested that CUL3 and DCDC2C's products have important roles in the sperm flagellum. Taken as a whole, our results demonstrate that an integrated genomics strategy can highlight relevant molecular factors in specific sperm components. This approach could be easily extended by including other "omics" data (from asthenozoospermic men, for example) and identifying other critical proteins from the human sperm microtubulome.

Morphine-withdrawal aversive memories and their extinction modulate H4K5 acetylation and Brd4 activation in the rat hippocampus and basolateral amygdala.

Chromatin modification is a crucial mechanism in several important phenomena in the brain, including drug addiction. Persistence of drug craving and risk of relapse could be attributed to drug-induced epigenetic mechanisms that seem to be candidates explaining long-lasting drug-induced behaviour and molecular alterations. Histone acetylation has been proposed to regulate drug-seeking behaviours and the extinction of rewarding memory of drug taking. In this work, we studied the epigenetic regulation during conditioned place aversion and after extinction of aversive memory of opiate withdrawal. Through immunofluorescence assays, we assessed some epigenetic marks (H4K5ac and p-Brd4) in crucial areas related to memory retrieval -basolateral amygdala (BLA) and hippocampus-. Additionally, to test the degree of transcriptional activation, we evaluated the immediate early genes (IEGs) response (Arc, Bdnf, Creb, Egr-1, Fos and Nfkb) and Smarcc1 (chromatin remodeler) through RT-qPCR in these nuclei. Our results showed increased p-Brd4 and H4K5ac levels during aversive memory retrieval, suggesting a more open chromatin state. However, transcriptional activation of these IEGs was not found, therefore suggesting that other secondary response may already be happening. Additionally, Smarcc1 levels were reduced due to morphine chronic administration in BLA and dentate gyrus. The activation markers returned to control levels after the retrieval of aversive memories, revealing a more repressed chromatin state. Taken together, our results show a major role of the tandem H4K5ac/p-Brd4 during the retrieval of aversive memories. These results might be useful to elucidate new molecular targets to improve and develop pharmacological treatments to address addiction and to avoid drug relapse.

Effect of Pharmaceutical Intervention in Pharmacologically Treated Hypertensive Patients-A Cluster-Randomized Clinical Trial: AFPRES-CLM Study.

BACKGROUND: Evaluate the effect of a community pharmaceutical intervention on the control of blood pressure in hypertensive patients treated pharmacologically. METHODS: A cluster-randomized clinical trial of 6 months was carried out. It was conducted in the Autonomous Community of Castilla-La Mancha (Spain). Sixty-three community pharmacies and 347 patients completed the study. Intervention patients received the community pharmaceutical intervention based on a protocol that addresses the individual needs of each patient related to the control of their blood pressure, which included Health Education, Pharmacotherapy Follow-up and 24 h Ambulatory Blood Pressure Measurement. Control patients received usual care in the community pharmacy. RESULTS: The pharmaceutical intervention resulted in better control of blood pressure (85.8% vs. 66.3% p < 0.001), lower use of emergencies (p = 0.002) and improvement trends in the physical components of quality of life, measured by SF-36 questionnaire, after 6 months of pharmaceutical intervention. No significant changes were observed for any of these variables in the control group. There were also detected 354 negative medication-related outcomes that were satisfactorily resolved in a 74.9% of the cases and 330 healthcare education interventions and 29 Ambulatory Blood Pressure Monitorings were performed in order to increase adherence to pharmacological treatment and minimize Negative Outcomes associated with Medication and prevent medication-related problems. CONCLUSIONS: Community pharmaceutical intervention can increase hypertensive patients with controlled blood pressure, after 6 months, compared with usual care.

Analysis of exonic regions involved in nuclear localization, splicing activity, and dimerization of Muscleblind-like-1 isoforms.

Muscleblind-like-1 (MBNL1) is a splicing regulatory factor controlling the fetal-to-adult alternative splicing transitions during vertebrate muscle development. Its capture by nuclear CUG expansions is one major cause for type 1 myotonic dystrophy (DM1). Alternative splicing produces MBNL1 isoforms that differ by the presence or absence of the exonic regions 3, 5, and 7. To understand better their respective roles and the consequences of the deregulation of their expression in DM1, here we studied the respective roles of MBNL1 alternative and constitutive exons. By combining genetics, molecular and cellular approaches, we found that (i) the exon 5 and 6 regions are both needed to control the nuclear localization of MBNL1; (ii) the exon 3 region strongly enhances the affinity of MBNL1 for its pre-mRNA target sites; (iii) the exon 3 and 6 regions are both required for the splicing regulatory activity, and this function is not enhanced by an exclusive nuclear localization of MBNL1; and finally (iv) the exon 7 region enhances MBNL1-MBNL1 dimerization properties. Consequently, the abnormally high inclusion of the exon 5 and 7 regions in DM1 is expected to enhance the potential of MBNL1 of being sequestered with nuclear CUG expansions, which provides new insight into DM1 pathophysiology.

Tau phosphorylation and sevoflurane anesthesia: an association to postoperative cognitive impairment.

BACKGROUND: There is a growing interest in the involvement of anesthetic agents in the etiology of postoperative cognitive dysfunction. Recent animal studies suggest that acute anesthesia induces transient hyperphosphorylation of tau, an effect essentially ascribed to hypothermia. The main aim of the present study was to investigate effects, in normothermic conditions, of acute or repeated exposure to sevoflurane, a halogenated anesthetic agent, on hippocampal tau phosphorylation and spatial memory in adult mice. METHODS: 5 to 6-month-old C57Bl6/J mice were submitted to acute (1 h) or repeated (five exposures of 1h every month) anesthesia using 1.5 or 2.5% sevoflurane, in normothermic conditions. In the acute protocol, animals were sacrificed 1 and 24 h after exposure. In the chronic protocol, spatial memory was evaluated using the Morris water maze following the fourth exposure, and tau phosphorylation evaluated 1 month following the last exposure using bi- and mono-dimensional electrophoresis. RESULTS: Acute sevoflurane anesthesia in normothermic conditions led to a significant dose-dependent and reversible hippocampal tau phosphorylation, 1 h following the end of exposure (P < 0.001). Conversely, repeated anesthesia led to persistent tau hyperphosphorylation and significant memory impairments, as seen in the retention phase of the Morris water maze in sevoflurane-anesthesized animals. These pathologic features may be related to the activation of both Akt and Erk pathways. CONCLUSIONS: The present study demonstrates, in mice, that sevoflurane exposure is associated with increased tau phosphorylation through specific kinases activation and spatial memory deficits. These data support a correlation between exposures to this anesthetic agent and cognitive decline.

Molecular Mechanisms Underlying the Retrieval and Extinction of Morphine Withdrawal-Associated Memories in the Basolateral Amygdala and Dentate Gyrus.

Despite their indisputable efficacy for pain management, opiate prescriptions remain highly controversial partially due to their elevated addictive potential. Relapse in drug use is one of the principal problems for addiction treatment, with drug-associated memories being among its main triggers. Consequently, the extinction of these memories has been proposed as a useful therapeutic tool. Hence, by using the conditioned place aversion (CPA) paradigm in rats, we investigated some of the molecular mechanisms that occurr during the retrieval and extinction of morphine withdrawal memories in the basolateral amygdala (BLA) and the hippocampal dentate gyrus (DG), which control emotional and episodic memories, respectively. The retrieval of aversive memories associated with the abstinence syndrome paralleled with decreased mTOR activity and increased Arc and GluN1 expressions in the DG. Additionally, Arc mRNA levels in this nucleus very strongly correlated with the CPA score exhibited by the opiate-treated rats. On the other hand, despite the unaltered mTOR phosphorylation, Arc levels augmented in the BLA. After the extinction test, Arc and GluN1 expressions were raised in both the DG and BLA of the control and morphine-treated animals. Remarkably, Homer1 expression in both areas correlated almost perfectly with the extinction showed by morphine-dependent animals. Moreover, Arc expression in the DG correlated strongly with the extinction of the CPA manifested by the group treated with the opiate. Finally, our results support the coordinated activity of some of these neuroplastic proteins for the extinction of morphine withdrawal memories in a regional-dependent manner. Present data provide evidence of differential expression and activity of synaptic molecules during the retrieval and extinction of aversive memories of opiate withdrawal in the amygdalar and hippocampal regions that will likely permit the development of therapeutic strategies able to minimize relapses induced by morphine withdrawal-associated aversive memories.

Beneficial effects of exercise in a transgenic mouse model of Alzheimer's disease-like Tau pathology.

Tau pathology is encountered in many neurodegenerative disorders known as tauopathies, including Alzheimer's disease. Physical activity is a lifestyle factor affecting processes crucial for memory and synaptic plasticity. Whether long-term voluntary exercise has an impact on Tau pathology and its pathophysiological consequences is currently unknown. To address this question, we investigated the effects of long-term voluntary exercise in the THY-Tau22 transgenic model of Alzheimer's disease-like Tau pathology, characterized by the progressive development of Tau pathology, cholinergic alterations and subsequent memory impairments. Three-month-old THY-Tau22 mice and wild-type littermates were assigned to standard housing or housing supplemented with a running wheel. After 9 months of exercise, mice were evaluated for memory performance and examined for hippocampal Tau pathology, cholinergic defects, inflammation and genes related to cholesterol metabolism. Exercise prevented memory alterations in THY-Tau22 mice. This was accompanied by a decrease in hippocampal Tau pathology and a prevention of the loss of expression of choline acetyltransferase within the medial septum. Whereas the expression of most cholesterol-related genes remained unchanged in the hippocampus of running THY-Tau22 mice, we observed a significant upregulation in mRNA levels of NPC1 and NPC2, genes involved in cholesterol trafficking from the lysosomes. Our data support the view that long-term voluntary physical exercise is an effective strategy capable of mitigating Tau pathology and its pathophysiological consequences.

Unraveling the molecular mechanisms involved in alcohol intake and withdrawal in adolescent mice exposed to alcohol during early life stages.

Alcohol interferes with foetal development and prenatal alcohol exposure can lead to adverse effects known as foetal alcohol spectrum disorders. We aimed to assess the underlying neurobiological mechanisms involved in alcohol intake and withdrawal in adolescent mice exposed to alcohol during early life stages, in discrete brain areas. Pregnant C57BL/6 female mice were exposed to binge alcohol drinking from gestation to weaning. Subsequently, alcohol seeking and taking behaviour were evaluated in male adolescent offspring, as assessed in the two-bottle choice and oral self-administration paradigms. Brain area samples were analysed to quantify AMPAR subunits GluR1/2 and pCREB/CREB expression following alcohol self-administration. We measured the expression of mu and kappa opioid receptors both during acute alcohol withdrawal (assessing anxiety alterations by the EPM test) and following reinstatement in the two-bottle choice paradigm. In addition, alcohol metabolism was analysed by measuring blood alcohol concentrations under an acute dose of 3 g/kg alcohol. Our findings demonstrate that developmental alcohol exposure enhances alcohol intake during adolescence, which is associated with a decrease in the pCREB/CREB ratio in the hippocampus, prefrontal cortex and striatum, while the GluR1/GluR2 ratio showed a decrease in the hippocampus. Moreover, PLAE mice showed behavioural alterations, such as increased anxiety-like responses during acute alcohol withdrawal, and higher BAC levels. No significant changes were identified for mu and kappa opioid receptors mRNA expression. The current study highlights that early alcohol exposed mice increased alcohol consumption during late adolescence. Furthermore, a diminished CREB signalling and glutamatergic neuroplasticity are proposed as underpinning neurobiological mechanisms involved in the sensitivity to alcohol reinforcing properties.

Cholinesterase activity in brain of senescence-accelerated-resistant mouse SAMR1 and its variation in brain of senescence-accelerated-prone mouse SAMP8.

The early-onset, irreversible, severe deficits of learning and memory in the senescence-accelerated mouse (SAM)-prone/8 (SAMP8) support its use as an animal model for human dementias of early onset. Possible implication of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) in cognitive dysfunction of SAMP8 mice was studied by comparing cholinesterase (ChE) expression in brains of SAMP8 mice and of their normal control, SAM-resistant/1 (SAMR1) mice. The level of ChE mRNAs was the same in SAMP8 and SAMR1 brains, which agreed with their equal AChE activity (3.09 +/- 1.45 vs. 3.07 +/- 1.44 mumol.hr(-1).mg protein(-1), U/mg), but not with a doubled BuChE activity in SAMP8 brain (0.14 +/- 0.05 vs. 0.07 +/- 0.02 U/mg; P < 0.01). This great increase in neural BuChE activity may contribute to cognitive deficit of SAMP8 mice. Hydrophilic (G(4) (H), 8%) and amphiphilic (G(4) (A), 74%) AChE tetramers, besides dimers and monomers (G(2) (A) + G(1) (A), 18%), were identified in SAMR1 brains. They also contained G(4) (H) BuChE forms (18%) as well as G(4) (A) (53%) and G(2) (A) + G(1) (A) (29%) species. Although SAMP8 brain displayed proportions of AChE and BuChE forms that were similar to those of SAMR1 brain, phenyl-agarose chromatography with detergent-free extracts showed a rise in the proportion of secretory G(4) (H) BuChE from 35% in SAMR1 to 44% in SAMP8 brain. The strong immunolabelling of glial fibrillary acidic protein (GFAP), a marker of reactive gliosis, in SAMP8 brain and the consideration of BuChE as a marker of glial cells suggest a relationship between phenotypic changes in neuroglial cells and the excess of BuChE activity in SAMP8 brain.

Correction to: Gel electrophoresis of human sperm: a simple method for evaluating sperm protein quality.

[This corrects the article DOI: 10.1186/s12610-018-0076-0.].

The level of butyrylcholinesterase activity increases and the content of the mRNA remains unaffected in brain of senescence-accelerated mouse SAMP8.

Looking at cholinesterases (ChEs) changes in age-related mental impairment, the expression of ChEs in brain of senescence accelerated-resistant (SAMR1) and senescence accelerated-prone (SAMP8) mice was studied. Acetylcholinesterase (AChE) activity was unmodified and BuChE activity increased twofold in SAMP8 brain. SAMR1 brain contained many AChE-T mRNAs, less BuChE and PRiMA mRNAs and scant AChE-R and AChE-H mRNAs. Their content unchanged in SAMP8 brain. Amphiphilic (G(4)(A)) and hydrophilic (G(4)(H)) AChE and BuChE tetramers, besides amphiphilic dimers (G(2)(A)) and monomers (G(1)(A)) were identified in SAMR1 brain and their distribution was little modified in SAMP8 brain. Blood plasma does not seem to provide the excess of BuChE activity in SAMP8 brain; it probably arises from glial cell changes owing to astrocytosis.

Two-Dimensional Electrophoresis Protocols to Analyze the Microtubule-Associated Tau Proteins from Several Biological Sources.

Technology breakthrough in proteomics enables to gather qualitative and quantitative information about a protein or a complex mixture of proteins. Two-dimensional gel electrophoresis remains an interesting technique, which provides an overview of the complexity of isovariants from a single protein when coupled to western blotting. Here, we describe a detailed protocol for the two-dimensional analysis of microtubule-associated Tau isovariants from cell to human or mouse brain tissue. We provide protocol enabling to separate native and Tau proteins that are aggregated in neurodegenerative disorders such as Alzheimer's disease.

Reduced Tau protein expression is associated with frontotemporal degeneration with progranulin mutation.

Reduction of Tau protein expression was described in 2003 by Zhukareva et al. in a variant of frontotemporal lobar degeneration (FTLD) referred to as diagnosis of dementia lacking distinctive histopathology, then re-classified as FTLD with ubiquitin inclusions. However, the analysis of Tau expression in FTLD has not been reconsidered since then. Knowledge of the molecular basis of protein aggregates and genes that are mutated in the FTLD spectrum would enable to determine whether the "Tau-less" is a separate pathological entity or if it belongs to an existing subclass of FTLD. To address this question, we have analyzed Tau expression in the frontal brain areas from control, Alzheimer's disease and FTLD cases, including FTLD- Tau (MAPT), FTLD-TDP (sporadic, FTLD-TDP-GRN, FTLD-TDP-C9ORF72) and sporadic FTLD-FUS, using western blot and 2D-DIGE (Two-Dimensional fluorescence Difference Gel Electrophoresis) approaches. Surprisingly, we found that most of the FTLD-TDP-GRN brains are characterized by a huge reduction of Tau protein expression without any decrease in Tau mRNA levels. Interestingly, only cases affected by point mutations, rather than cases with total deletion of one GRN allele, seem to be affected by this reduction of Tau protein expression. Moreover, proteomic analysis highlighted correlations between reduced Tau protein level, synaptic impairment and massive reactive astrogliosis in these FTLD-GRN cases. Consistent with a recent study, our data also bring new insights regarding the role of progranulin in neurodegeneration by suggesting its involvement in lysosome and synaptic regulation. Together, our results demonstrate a strong association between progranulin deficiency and reduction of Tau protein expression that could lead to severe neuronal and glial dysfunctions. Our study also indicates that this FTLD-TDP-GRN subgroup could be part as a distinct entity of FTLD classification.

Role of the Tau N-terminal region in microtubule stabilization revealed by new endogenous truncated forms.

Tau is a central player in Alzheimer's disease (AD) and related Tauopathies, where it is found as aggregates in degenerating neurons. Abnormal post-translational modifications, such as truncation, are likely involved in the pathological process. A major step forward in understanding the role of Tau truncation would be to identify the precise cleavage sites of the several truncated Tau fragments that are observed until now in AD brains, especially those truncated at the N-terminus, which are less characterized than those truncated at the C-terminus. Here, we optimized a proteomics approach and succeeded in identifying a number of new N-terminally truncated Tau species from the human brain. We initiated cell-based functional studies by analyzing the biochemical characteristics of two N-terminally truncated Tau species starting at residues Met11 and Gln124 respectively. Our results show, interestingly, that the Gln124-Tau fragment displays a stronger ability to bind and stabilize microtubules, suggesting that the Tau N-terminal domain could play a direct role in the regulation of microtubule stabilization. Future studies based on our new N-terminally truncated-Tau species should improve our knowledge of the role of truncation in Tau biology as well as in the AD pathological process.

MBNL Sequestration by Toxic RNAs and RNA Misprocessing in the Myotonic Dystrophy Brain.

For some neurological disorders, disease is primarily RNA mediated due to expression of non-coding microsatellite expansion RNAs (RNA(exp)). Toxicity is thought to result from enhanced binding of proteins to these expansions and depletion from their normal cellular targets. However, experimental evidence for this sequestration model is lacking. Here, we use HITS-CLIP and pre-mRNA processing analysis of human control versus myotonic dystrophy (DM) brains to provide compelling evidence for this RNA toxicity model. MBNL2 binds directly to DM repeat expansions in the brain, resulting in depletion from its normal RNA targets with downstream effects on alternative splicing and polyadenylation. Similar RNA processing defects were detected in Mbnl compound-knockout mice, highlighted by dysregulation of Mapt splicing and fetal tau isoform expression in adults. These results demonstrate that MBNL proteins are directly sequestered by RNA(exp) in the DM brain and introduce a powerful experimental tool to evaluate RNA-mediated toxicity in other expansion diseases.

Brain pathology in myotonic dystrophy: when tauopathy meets spliceopathy and RNAopathy.

Myotonic dystrophy (DM) of type 1 and 2 (DM1 and DM2) are inherited autosomal dominant diseases caused by dynamic and unstable expanded microsatellite sequences (CTG and CCTG, respectively) in the non-coding regions of the genes DMPK and ZNF9, respectively. These mutations result in the intranuclear accumulation of mutated transcripts and the mis-splicing of numerous transcripts. This so-called RNA gain of toxic function is the main feature of an emerging group of pathologies known as RNAopathies. Interestingly, in addition to these RNA inclusions, called foci, the presence of neurofibrillary tangles (NFT) in patient brains also distinguishes DM as a tauopathy. Tauopathies are a group of nearly 30 neurodegenerative diseases that are characterized by intraneuronal protein aggregates of the microtubule-associated protein Tau (MAPT) in patient brains. Furthermore, a number of neurodegenerative diseases involve the dysregulation of splicing regulating factors and have been characterized as spliceopathies. Thus, myotonic dystrophies are pathologies resulting from the interplay among RNAopathy, spliceopathy, and tauopathy. This review will describe how these processes contribute to neurodegeneration. We will first focus on the tauopathy associated with DM1, including clinical symptoms, brain histology, and molecular mechanisms. We will also discuss the features of DM1 that are shared by other tauopathies and, consequently, might participate in the development of a tauopathy. Moreover, we will discuss the determinants common to both RNAopathies and spliceopathies that could interfere with tau-related neurodegeneration.