Léčba akutní a chronické bolesti je nezbytnou součástí každodenní lékařské praxe. V případech refrakterní bolesti, která nereaguje adekvátně na zavedené léčebné metody, se hledají nové možnosti, které nabízejí perspektivu úspěšné léčby. Botulotoxin je další možnou variantou konzervativní léčby některých refrakterních bolestivých stavů, která se v posledních letech dostala do popředí zájmu. Botulotoxin zabraňuje presynaptickému uvolňování acetylcholinu na nervosvalové ploténce. Tato ireverzibilní inhibice vede k přerušení nervosvalového přenosu, a tím k oslabení svalů, které nastává po několika dnech a obvykle trvá 3–6 měsíců. V oblasti terapie bolesti bylo prokázáno, že botulotoxin blokuje nejen nervosvalový přenos, ale také bolest podporující sekreci neuropeptidů, jako je substance P, glutamát a peptid související s kalcitoninovým genem (CGRP).
Treatment of acute and chronic pain is an essential part of everyday medical practice. In cases of refractory pain that does not respond adequately to established therapeutic methods, new options are being sought that offer the prospect of successful treatment as an additive form of therapy. Botulinum toxin is another possible option for the conservative treatment of some refractory pain conditions that has come to the fore in recent years. Botulinum toxin prevents presynaptic release of acetylcholine at the motor end plate. This irreversible inhibition leads to an interruption of neuromuscular transmission, resulting in muscle weakness that occurs after a few days and usually lasts 3–6 months. Within a few weeks after botulinum toxin treatment, there is collateral axon ingrowth at the terminal motor plate and eventually restitution of the neuromuscular synapse and an increase in strength of the treated muscle. In the context of peripheral sensitization, botulinum toxin has been shown to block not only neuromuscular transmission but also the secretion of neuropeptides such as substance P, glutamate, and calcitonin gene-related peptide (CGRP).
The serotonergic psychedelics psilocybin, LSD and DMT hold great promise for the development of new treatments for psychiatric conditions such as major depressive disorder, addiction and end-of-life anxiety. Previous studies in both animals and humans have confirmed the effects of these drugs on neuronal activity and plasticity. However, the understanding of the mechanisms of action of these substances is limited. Here we show rapid effects of psychedelics on presynaptic properties, using live cell imaging at the level of single synapses in primary rat cortical neurons. Using the genetically encoded reporter of synaptic vesicle fusion synaptopHluorin, we detected a reduced fraction of synaptic vesicles that fused in response to mild or strong electrical stimulation 3-30 min after application of serotonergic psychedelics. These effects were transient and no longer present 24 h after treatment. While DMT only reduced the total recycling pool, LSD and psilocin also reduced the size of the readily releasable vesicle pool. Imaging with the sensors for glutamate, iGluSnFR, and presynaptic calcium, synGCaMP6, showed that while psilocin and DMT increased evoked glutamate release, LSD and psilocin reduced evoked presynaptic calcium levels. Interestingly, psilocin also affected short-term plasticity leading to a depression of responses to paired stimuli. The rapid and drug-specific modulation of glutamatergic neurotransmission described in this study may contribute to distinct anxiolytic and antidepressant properties of serotonergic psychedelics.
- MeSH
- Hallucinogens * pharmacology MeSH
- Rats MeSH
- Cells, Cultured MeSH
- Glutamic Acid * metabolism MeSH
- Lysergic Acid Diethylamide pharmacology MeSH
- Cerebral Cortex * drug effects metabolism cytology MeSH
- Neurons * drug effects metabolism MeSH
- Rats, Sprague-Dawley MeSH
- Psilocybin pharmacology MeSH
- Serotonin Agents pharmacology MeSH
- Synaptic Vesicles drug effects metabolism MeSH
- Tryptamines pharmacology MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Rasopathies are genetic disorders often associated with developmental delay and intellectual disability. Noonan syndrome (NS) is one of the most common Rasopathies, caused by mutations in PTPN11 in more than 50% of cases. In mammalian neurons, PTPN11 controls the trafficking of postsynaptic glutamate receptors. This process is disrupted in neurons expressing PTPN11 variants associated with Rasopathies and is thought to contribute to the cognitive impairments in Noonan syndrome. Recent work revealed presynaptic impairments upon expression of RASopathy-linked PTPN11 variants in Drosophila. However, the presynaptic role of PTPN11 has not yet been addressed in mammals. Here, we investigated membrane trafficking of synaptic vesicles in cultured mouse cortical neurons expressing Rasopathy-associated PTPN11D61Y variant. We observed a significantly smaller readily releasable and total recycling pool of synaptic vesicles. The drop in synaptic vesicle release competence was accompanied by a decreased rate of SV retrieval. Interestingly, the presynaptic phenotype was evident in mature (DIV21) but not in immature (DIV12) neurons. Thus, our data reveal importance of balanced PTPN11 activity for normal trafficking of neurotransmitter-filled synaptic vesicles in the presynaptic ending of mature neurons.
- MeSH
- Cells, Cultured MeSH
- Mutation genetics MeSH
- Mice MeSH
- Neurons metabolism MeSH
- Aging genetics metabolism MeSH
- Synaptic Vesicles * metabolism MeSH
- Protein Tyrosine Phosphatase, Non-Receptor Type 11 * metabolism genetics MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Botulinum neurotoxins (BoNTs) and tetanus toxin (TeTX) are the deadliest biological substances that cause botulism and tetanus, respectively. Their astonishing potency and capacity to enter neurons and interfere with neurotransmitter release at presynaptic terminals have attracted much interest in experimental neurobiology and clinical research. Fused with reporter proteins or labelled with fluorophores, BoNTs and TeTX and their non-toxic fragments also offer remarkable opportunities to visualize cellular processes and functions in neurons and synaptic connections. This study presents the state-of-the-art optical probes derived from BoNTs and TeTX and discusses their applications in molecular and synaptic biology and neurodevelopmental research. It reviews the principles of the design and production of probes, revisits their applications with advantages and limitations and considers prospects for future improvements. The versatile characteristics of discussed probes and reporters make them an integral part of the expanding toolkit for molecular neuroimaging, promoting the discovery process in neurobiology and translational neurosciences.
- MeSH
- Botulinum Toxins chemistry MeSH
- Fluorescent Dyes chemistry MeSH
- Humans MeSH
- Molecular Probes chemistry MeSH
- Neurons * metabolism MeSH
- Neurotoxins * MeSH
- Neuroimaging * methods MeSH
- Synapses * metabolism MeSH
- Tetanus Toxin * chemistry MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
Three decades ago, the first endocannabinoid, anandamide (AEA), was identified, and its analgesic effect was recognized in humans and preclinical models. However, clinical trial failures pointed out the complexity of the AEA-induced analgesia. The first synapses in the superficial laminae of the spinal cord dorsal horn represent an important modulatory site in nociceptive transmission and subsequent pain perception. The glutamatergic synaptic transmission at these synapses is strongly modulated by two primary AEA-activated receptors, cannabinoid receptor 1 (CB1) and transient receptor potential vanilloid 1 (TRPV1), both highly expressed on the presynaptic side formed by the endings of primary nociceptive neurons. Activation of these receptors can have predominantly inhibitory (CB1) and excitatory (TRPV1) effects that are further modulated under pathological conditions. In addition, dual AEA-mediated signaling and action may occur in primary sensory neurons and dorsal horn synapses. AEA application causes balanced inhibition and excitation of primary afferent synaptic input on superficial dorsal horn neurons in normal conditions, whereas peripheral inflammation promotes AEA-mediated inhibition. This review focuses mainly on the modulation of synaptic transmission at the spinal cord level and signaling in primary nociceptive neurons by AEA via CB1 and TRPV1 receptors. Furthermore, the spinal analgesic effect in preclinical studies and clinical aspects of AEA-mediated analgesia are considered.
- MeSH
- Endocannabinoids * metabolism MeSH
- TRPV Cation Channels metabolism MeSH
- Arachidonic Acids * metabolism pharmacology MeSH
- Humans MeSH
- Spinal Cord * metabolism drug effects MeSH
- Synaptic Transmission * physiology drug effects MeSH
- Nociception physiology drug effects MeSH
- Nociceptors metabolism drug effects physiology MeSH
- Polyunsaturated Alkamides * metabolism MeSH
- Receptor, Cannabinoid, CB1 metabolism MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
This review represents a continuation of the already published surveys on substances used in local, general inhalational, and intravenous anesthesia. The administration of a single active substance in these applications is rare, as it is not capable of inducing anesthesia without seriously compromising hemodynamic or respiratory functions, aggravating the operating conditions, or delaying the postoperative recovery. For this reason, other agents (benzodiazepines, opioid analgesics, presynaptic α2-adrenergic receptor agonists and peripheral myorelaxants) are standard components of general anesthesia (in addition to the anesthetic agents listed in the previous reviews), which improve the profile of each anesthetic agent. Each additive has an effect on the properties of the anesthetics used. The review contains the characteristics of individual groups of co-administered substances with their chemical structure, chemical IUPAC name, and pharmacological and pharmacokinetic profile. Chemical structures are organized into groups according to their structure or pharmacological effect and attention is also paid to their stereochemistry (presence of stereogenic center, chair form of cyclic systems).
- MeSH
- Anesthetics * pharmacology therapeutic use MeSH
- Benzodiazepines pharmacology therapeutic use MeSH
- Humans MeSH
- Analgesics, Opioid pharmacology therapeutic use MeSH
- Check Tag
- Humans MeSH
- Publication type
- Review MeSH
OBJECTIVE: To apply a machine learning analysis to clinical and presynaptic dopaminergic imaging data of patients with rapid eye movement (REM) sleep behavior disorder (RBD) to predict the development of Parkinson disease (PD) and dementia with Lewy bodies (DLB). METHODS: In this multicenter study of the International RBD study group, 173 patients (mean age 70.5 ± 6.3 years, 70.5% males) with polysomnography-confirmed RBD who eventually phenoconverted to overt alpha-synucleinopathy (RBD due to synucleinopathy) were enrolled, and underwent baseline presynaptic dopaminergic imaging and clinical assessment, including motor, cognitive, olfaction, and constipation evaluation. For comparison, 232 RBD non-phenoconvertor patients (67.6 ± 7.1 years, 78.4% males) and 160 controls (68.2 ± 7.2 years, 53.1% males) were enrolled. Imaging and clinical features were analyzed by machine learning to determine predictors of phenoconversion. RESULTS: Machine learning analysis showed that clinical data alone poorly predicted phenoconversion. Presynaptic dopaminergic imaging significantly improved the prediction, especially in combination with clinical data, with 77% sensitivity and 85% specificity in differentiating RBD due to synucleinopathy from non phenoconverted RBD patients, and 85% sensitivity and 86% specificity in discriminating PD-converters from DLB-converters. Quantification of presynaptic dopaminergic imaging showed that an empirical z-score cutoff of -1.0 at the most affected hemisphere putamen characterized RBD due to synucleinopathy patients, while a cutoff of -1.0 at the most affected hemisphere putamen/caudate ratio characterized PD-converters. INTERPRETATION: Clinical data alone poorly predicted phenoconversion in RBD due to synucleinopathy patients. Conversely, presynaptic dopaminergic imaging allows a good prediction of forthcoming phenoconversion diagnosis. This finding may be used in designing future disease-modifying trials. ANN NEUROL 2024;95:1178-1192.
- MeSH
- Lewy Body Disease * diagnostic imaging MeSH
- Dopamine * metabolism MeSH
- Tomography, Emission-Computed, Single-Photon MeSH
- Middle Aged MeSH
- Humans MeSH
- Parkinson Disease * diagnostic imaging complications MeSH
- REM Sleep Behavior Disorder * diagnostic imaging MeSH
- Presynaptic Terminals metabolism MeSH
- Aged MeSH
- Machine Learning * MeSH
- Synucleinopathies * diagnostic imaging MeSH
- Dopaminergic Imaging MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Multicenter Study MeSH
Anandamide (AEA) is an important modulator of nociception in the spinal dorsal horn, acting presynaptically through Cannabinoid (CB1) and Transient receptor potential vanilloid (TRPV1) receptors. The role of AEA (1 μM, 10 μM, and 30 μM) application on the modulation of nociceptive synaptic transmission under control and inflammatory conditions was studied by recording miniature excitatory postsynaptic currents (mEPSCs) from neurons in spinal cord slices. Inhibition of the CB1 receptors by PF514273, TRPV1 by SB366791, and the fatty acid amide hydrolase (FAAH) by URB597 was used. Under naïve conditions, the AEA application did not affect the mEPSCs frequency (1.43±0.12 Hz) when all the recorded neurons were considered. The mEPSC frequency increased (180.0±39.2%) only when AEA (30 μM) was applied with PF514273 and URB597. Analysis showed that one sub-population of neurons had synaptic input inhibited (39.1% of neurons), the second excited (43.5%), whereas 8.7% showed a mixed effect and 8.7% did not respond to the AEA. With inflammation, the AEA effect was highly inhibitory (72.7%), while the excitation was negligible (9.1%), and 18.2% were not modulated. After inflammation, more neurons (45.0%) responded even to low AEA by mEPSC frequency increase with PF514273/URB597 present. AEA-induced dual (excitatory/inhibitory) effects at the 1st nociceptive synapse should be considered when developing analgesics targeting the endocannabinoid system. These findings contrast the clear inhibitory effects of the AEA precursor 20:4-NAPE application described previously and suggest that modulation of endogenous AEA production may be more favorable for analgesic treatments.
- MeSH
- Amidohydrolases MeSH
- Analgesics pharmacology MeSH
- Benzamides * MeSH
- Endocannabinoids * pharmacology MeSH
- Carbamates * MeSH
- Arachidonic Acids * MeSH
- Humans MeSH
- Nociception * MeSH
- Polyunsaturated Alkamides pharmacology MeSH
- Spinal Cord Dorsal Horn MeSH
- Inflammation drug therapy MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Ketamine is clinically used fast-acting antidepressant. Its metabolite hydroxynorketamine (HNK) shows a robust antidepressant effect in animal studies. It is unclear, how these chemically distinct compounds converge on similar neuronal effects. While KET acts mostly as N-methyl-d-aspartate receptor (NMDAR) antagonist, the molecular target of HNK remains enigmatic. Here, we show that KET and HNK converge on rapid inhibition of glutamate release by reducing the release competence of synaptic vesicles and induce nuclear translocation of pCREB that controls expression of neuroplasticity genes connected to KET- and HNK-mediated antidepressant action. Ro25-6981, a selective antagonist of GluN2B, mimics effect of KET indicating that GluN2B-containing NMDAR might mediate the presynaptic effect of KET. Selective antagonist of α7 nicotinic acetylcholine receptors (α7nAChRs) or genetic deletion of Chrna7, its pore-forming subunit, fully abolishes HNK-induced synaptic and nuclear regulations, but leaves KET-dependent cellular effects unaffected. Thus, KET or HNK-induced modulation of synaptic transmission and nuclear translocation of pCREB can be mediated by selective signaling via NMDAR or α7nAChRs, respectively. Due to the rapid metabolism of KET to HNK, it is conceivable that subsequent modulation of glutamatergic and cholinergic neurotransmission affects circuits in a cell-type-specific manner and contributes to the therapeutic potency of KET. This finding promotes further exploration of new combined medications for mood disorders.
Elevated impulsivity is a key component of attention-deficit hyperactivity disorder (ADHD), bipolar disorder and juvenile myoclonic epilepsy (JME). We performed a genome-wide association, colocalization, polygenic risk score, and pathway analysis of impulsivity in JME (n = 381). Results were followed up with functional characterisation using a drosophila model. We identified genome-wide associated SNPs at 8q13.3 (P = 7.5 × 10-9) and 10p11.21 (P = 3.6 × 10-8). The 8q13.3 locus colocalizes with SLCO5A1 expression quantitative trait loci in cerebral cortex (P = 9.5 × 10-3). SLCO5A1 codes for an organic anion transporter and upregulates synapse assembly/organisation genes. Pathway analysis demonstrates 12.7-fold enrichment for presynaptic membrane assembly genes (P = 0.0005) and 14.3-fold enrichment for presynaptic organisation genes (P = 0.0005) including NLGN1 and PTPRD. RNAi knockdown of Oatp30B, the Drosophila polypeptide with the highest homology to SLCO5A1, causes over-reactive startling behaviour (P = 8.7 × 10-3) and increased seizure-like events (P = 6.8 × 10-7). Polygenic risk score for ADHD genetically correlates with impulsivity scores in JME (P = 1.60 × 10-3). SLCO5A1 loss-of-function represents an impulsivity and seizure mechanism. Synaptic assembly genes may inform the aetiology of impulsivity in health and disease.
- Publication type
- Journal Article MeSH
