The European journal of neuroscience
Quirion, B;Beaulieu, C;Côté, L;Parent, JL;Gendron, L;
PMID: 35674691 | DOI: 10.1111/ejn.15733
Primary afferents are responsible for transmitting signals produced by noxious stimuli from the periphery to the spinal cord. Mu and delta opioid receptors (MOP and DOP) have analgesic properties and are highly expressed in dorsal root ganglia (DRG) neurons. In humans, spinal DOP is almost exclusively located on central terminals of DRG neurons, whereas in rodents, it is expressed both on presynaptic terminals and spinal neurons. In this study, we aimed to assess the distribution of MOP and DOP in the DRGs of mice and rats. Using in situ hybridization and immunofluorescence, we visualized MOP and DOP mRNA together with various neuronal markers. In rats and mice, we show that both receptors are expressed, albeit to different extents, in all types of neurons, namely, large and medium myelinated neurons (NF200-positive), small nonpeptidergic (IB4- or P2X3R-positive) and peptidergic C fibres (Tac1-positive). Overall, DOP mRNA was found to be mainly expressed in large and medium myelinated neurons, whereas MOP mRNA was mainly found in C fibres. The distribution of MOP and DOP, however, slightly differs between rats and mice, with a higher proportion of small nonpeptidergic C fibres expressing DOP mRNA in mice than in rats. We further found that neither morphine nor inflammation affected the distribution of the receptor mRNA. Because of their location, our results confirm that MOP and DOP have the potential to alleviate similar types of pain and that this effect could slightly differ between species.
Polgár, E;Dickie, AC;Gutierrez-Mecinas, M;Bell, AM;Boyle, KA;Quillet, R;Rashid, EA;Clark, RA;German, MT;Watanabe, M;Riddell, JS;Todd, AJ;
PMID: 35543635 | DOI: 10.1097/j.pain.0000000000002677
Neurons in the superficial dorsal horn that express the gastrin-releasing peptide receptor (GRPR) are strongly implicated in spinal itch pathways. However, a recent study reported that many of these correspond to vertical cells, a population of interneurons that are thought to transmit nociceptive information. In this study, we have used a GRPRCreERT2 mouse line to identify and target cells that possess Grpr mRNA. We find that the GRPR cells are highly concentrated in lamina I and the outer part of lamina II, that they are all glutamatergic, and that they account for ∼15% of the excitatory neurons in the superficial dorsal horn. We had previously identified 6 neurochemically distinct excitatory interneuron populations in this region based on neuropeptide expression and the GRPR cells are largely separate from these, although they show some overlap with cells that express substance P. Anatomical analysis revealed that the GRPR neurons are indeed vertical cells, and that their axons target each other, as well as arborising in regions that contain projection neurons: lamina I, the lateral spinal nucleus and the lateral part of lamina V. Surprisingly, given the proposed role of GRPR cells in itch, we found that most of the cells received monosynaptic input from Trpv1-expressing (nociceptive) afferents, that the great majority responded to noxious and pruritic stimuli, and that chemogenetically activating them resulted in pain- and itch-related behaviours. Together, these findings suggest that the GRPR cells are involved in spinal cord circuits that underlie both pain and itch.
Sodium leak channel contributes to neuronal sensitization in neuropathic pain
Zhang, D;Zhao, W;Liu, J;Ou, M;Liang, P;Li, J;Chen, Y;Liao, D;Bai, S;Shen, J;Chen, X;Huang, H;Zhou, C;
PMID: 33766679 | DOI: 10.1016/j.pneurobio.2021.102041
Neuropathic pain affects up to 10% of the total population and no specific target is ideal for therapeutic need. The sodium leak channel (NALCN), a non-selective cation channel, mediates the background Na+ leak conductance and controls neuronal excitability and rhythmic behaviors. Here, we show that increases of NALCN expression and function in dorsal root ganglion (DRG) and dorsal spinal cord contribute to chronic constriction injury (CCI)-induced neuropathic pain in rodents. NALCN current and neuronal excitability in acutely isolated DRG neurons and spinal cord slices of rats were increased after CCI which were decreased to normal levels by NALCN-siRNA. Accordingly, pain-related symptoms were significantly alleviated by NALCN-siRNA-mediated NALCN knockdown and completely prevented by NALCN-shRNA-mediated NALCN knockdown in rats or by conditional NALCN knockout in mice. Our results indicate that increases in NALCN expression and function contribute to CCI-induced neuronal sensitization; therefore, NALCN may be a novel molecular target for control of neuropathic pain.
Ramberg, I;Vieira, FG;Toft, PB;von Buchwald, C;Heegaard, S;
PMID: 35626161 | DOI: 10.3390/cancers14102558
The pathogenesis of squamous cell neoplasms arising in the lacrimal drainage system is poorly understood, and the underlying genomic drivers for disease development remain unexplored. We aimed to investigate the genomic aberrations in carcinomas arising in the LDS and correlate the findings to human papillomavirus (HPV) status. The HPV analysis was performed using HPV DNA PCR, HPV E6/E7 mRNA in-situ hybridization, and p16 immunohistochemistry. The genomic characterization was performed by targeted DNA sequencing of 523 cancer-relevant genes. Patients with LDS papilloma (n = 17) and LDS carcinoma (n = 15) were included. There was a male predominance (68%) and a median age at diagnosis of 46.0 years (range 27.5-65.5 years) in patients with papilloma and 63.8 years (range 34.0-87.2 years) in patients with carcinoma. Transcriptional activity of the HPV E6/E7 oncogenes was detected in the whole tumor thickness in 12/15 (80%) papillomas (HPV6, 11, 16) and 10/15 (67%) squamous cell carcinomas (SCC) (HPV11: 3/15 (20%) and HPV16: 7/15 (47%)). Pathogenic variants in PIK3CA, FGFR3, AKT1, and PIK3R1, wildtype TP53, p16 overexpression, and deregulated high-risk E6/E7 transcription characterized the HPV16-positive SCC. The deregulated pattern of HPV E6/E7 expression, correlating with HPV DNA presence and p16 positivity, supports a causal role of HPV in a subset of LDS papillomas and carcinomas. The viral and molecular profile of LDS SCC resembles that of other HPV-driven SCC.
Hennessy ML, Corcoran A, Brust RD, Nattie EE, Dymecki S.
PMID: 28073937 | DOI: 10.1523/JNEUROSCI.2316-16.2016
Homeostatic control of breathing, heart rate, and body temperature relies on circuits within the brainstem modulated by the neurotransmitter serotonin (5-HT). Mounting evidence points to specialized neuronal subtypes within the 5-HT system, which have borne out in functional studies, including the modulation of distinct facets of homeostatic control. These functional differences, read out at the organismal level, are likely subserved by differences among 5-HT neuron subtypes at the cellular and molecular levels, including differences in the capacity to co-express other neurotransmitters such as glutamate, GABA, thyrotropin releasing hormone, and substance P encoded by the Tachykinin-1 (Tac1) gene. Here we characterize in mice a 5-HT neuron subtype identified by expression of Tac1 and the transcription factor gene Pet1, thus referred to as the Tac1-Pet1 neuron subtype. Transgenic cell labeling showed Tac1-Pet1 soma resident largely in the caudal medulla. Chemogenetic (CNO-hM4Di) perturbation of Tac1-Pet1 neuron activity resulted in blunting of the respiratory CO2 chemoreflex, which normally augments ventilation in response to hypercapnic acidosis to restore normal pH and PCO2 Tac1-Pet1 axonal boutons were found localized to brainstem areas implicated in respiratory modulation, with highest density in motor nuclei. These findings demonstrate that the activity of a Pet1 neuron subtype with potential to release both 5-HT and substance P is necessary for normal respiratory dynamics, likely via motor outputs that maintain airway patency and engage muscles of respiration. These Tac1-Pet1 neurons may complement the activity of Egr2-Pet1 neurons, previously established in respiratory chemoreception, but which do not innervate respiratory motor nuclei.
SIGNIFICANCE STATEMENT:
5-HT neurons modulate outputs as diverse as body temperature, respiration, aggression, and mood. We characterize a 5-HT neuron subtype defined by expression of Tachykinin1 and Pet1 (Tac1-Pet1 neurons) which projects to respiratory motor nuclei, and when silenced, blunts the ventilatory response to inhaled carbon dioxide. We employ genetic tools to access this subset of 5-HT neurons to query function, anatomy, and connectivity. Localization of synaptic boutons from Tac1-Pet1 neurons, primarily within motor regions, contrasts with those from previously described Egr2-Pet1 neurons, which are chemosensitive and reside in the raphe magnus and project primarily to chemosensory integration, but not motor, regions of the brainstem.
Yao, Y;Barger, Z;Saffari Doost, M;Tso, CF;Darmohray, D;Silverman, D;Liu, D;Ma, C;Cetin, A;Yao, S;Zeng, H;Dan, Y;
PMID: 36170850 | DOI: 10.1016/j.neuron.2022.08.027
Sleep disturbances are strongly associated with cardiovascular diseases. Baroreflex, a basic cardiovascular regulation mechanism, is modulated by sleep-wake states. Here, we show that neurons at key stages of baroreflex pathways also promote sleep. Using activity-dependent genetic labeling, we tagged neurons in the nucleus of the solitary tract (NST) activated by blood pressure elevation and confirmed their barosensitivity with optrode recording and calcium imaging. Chemogenetic or optogenetic activation of these neurons promoted non-REM sleep in addition to decreasing blood pressure and heart rate. GABAergic neurons in the caudal ventrolateral medulla (CVLM)-a downstream target of the NST for vasomotor baroreflex-also promote non-REM sleep, partly by inhibiting the sympathoexcitatory and wake-promoting adrenergic neurons in the rostral ventrolateral medulla (RVLM). Cholinergic neurons in the nucleus ambiguous-a target of the NST for cardiac baroreflex-promoted non-REM sleep as well. Thus, key components of the cardiovascular baroreflex circuit are also integral to sleep-wake brain-state regulation.
Complete representation of action space and value in all dorsal striatal pathways
Weglage, M;Wärnberg, E;Lazaridis, I;Calvigioni, D;Tzortzi, O;Meletis, K;
PMID: 34320355 | DOI: 10.1016/j.celrep.2021.109437
The dorsal striatum plays a central role in the selection, execution, and evaluation of actions. An emerging model attributes action selection to the matrix and evaluation to the striosome compartment. Here, we use large-scale cell-type-specific calcium imaging to determine the activity of striatal projection neurons (SPNs) during motor and decision behaviors in the three major outputs of the dorsomedial striatum: Oprm1+ striosome versus D1+ direct and A2A+ indirect pathway SPNs. We find that Oprm1+ SPNs show complex tunings to simple movements and value-guided actions, which are conserved across many sessions in a single task but remap between contexts. During decision making, the SPN tuning profiles form a complete representation in which sequential SPN activity jointly encodes task progress and value. We propose that the three major output pathways in the dorsomedial striatum share a similarly complete representation of the entire action space, including task- and phase-specific signals of action value and choice.
Advanced science (Weinheim, Baden-Wurttemberg, Germany)
Yi, T;Wang, N;Huang, J;Wang, Y;Ren, S;Hu, Y;Xia, J;Liao, Y;Li, X;Luo, F;Ouyang, Q;Li, Y;Zheng, Z;Xiao, Q;Ren, R;Yao, Z;Tang, X;Wang, Y;Chen, X;He, C;Li, H;Hu, Z;
PMID: 36961096 | DOI: 10.1002/advs.202300189
Sevoflurane has been the most widely used inhaled anesthetics with a favorable recovery profile; however, the precise mechanisms underlying its anesthetic action are still not completely understood. Here the authors show that sevoflurane activates a cluster of urocortin 1 (UCN1+ )/cocaine- and amphetamine-regulated transcript (CART+ ) neurons in the midbrain involved in its anesthesia. Furthermore, growth hormone secretagogue receptor (GHSR) is highly enriched in sevoflurane-activated UCN1+ /CART+ cells and is necessary for sleep induction. Blockade of GHSR abolishes the excitatory effect of sevoflurane on UCN1+ /CART+ neurons and attenuates its anesthetic effect. Collectively, their data suggest that anesthetic action of sevoflurane necessitates the GHSR activation in midbrain UCN1+ /CART+ neurons, which provides a novel target including the nucleus and receptor in the field of anesthesia.
Zhu, YB;Wang, Y;Hua, XX;Xu, L;Liu, MZ;Zhang, R;Liu, PF;Li, JB;Zhang, L;Mu, D;
PMID: 35167440 | DOI: 10.7554/eLife.68372
Long-lasting negative affections dampen enthusiasm for life, and dealing with negative affective states is essential for individual survival. The parabrachial nucleus (PBN) and thalamic paraventricular nucleus (PVT) are critical for modulating affective states in mice. However, the functional roles of PBN-PVT projections in modulating affective states remain elusive. Here, we show that PBN neurons send dense projection fibers to the PVT and form direct excitatory synapses with PVT neurons. Activation of the PBN-PVT pathway induces robust behaviors associated with negative affective states without affecting nociceptive behaviors. Inhibition of the PBN-PVT pathway reduces aversion-like and fear-like behaviors. Furthermore, the PVT neurons innervated by the PBN are activated by aversive stimulation, and activation of PBN-PVT projections enhances the neuronal activity of PVT neurons in response to the aversive stimulus. Consistently, activation of PVT neurons that received PBN-PVT projections induces anxiety-like behaviors. Thus, our study indicates that PBN-PVT projections modulate negative affective states in mice.
International journal of gynecological pathology : official journal of the International Society of Gynecological Pathologists
Stolnicu, S;Hoang, L;Zhou, Q;Iasonos, A;Terinte, C;Pesci, A;Aviel-Ronen, S;Kiyokawa, T;Alvarado-Cabrero, I;Oliva, E;Park, KJ;Soslow, RA;
PMID: 36044310 | DOI: 10.1097/PGP.0000000000000921
Although both the 2014 and 2020 World Health Organization (WHO) criteria require unequivocal glandular and squamous differentiation for a diagnosis of cervical adenosquamous carcinoma (ASC), in practice, ASC diagnoses are often made in tumors that lack unequivocal squamous and/or glandular differentiation. Considering the ambiguous etiologic, morphologic, and clinical features and outcomes associated with ASCs, we sought to redefine these tumors. We reviewed slides from 59 initially diagnosed ASCs (including glassy cell carcinoma and related lesions) to confirm an ASC diagnosis only in the presence of unequivocal malignant glandular and squamous differentiation. Select cases underwent immunohistochemical profiling as well as human papillomavirus (HPV) testing by in situ hybridization. Of the 59 cases originally classified as ASCs, 34 retained their ASC diagnosis, 9 were reclassified as pure invasive stratified mucin-producing carcinomas, 10 as invasive stratified mucin-producing carcinomas with other components (such as HPV-associated mucinous, usual-type, or ASCs), and 4 as HPV-associated usual or mucinous adenocarcinomas with benign-appearing squamous metaplasia. Two glassy adenocarcinomas were reclassified as poorly differentiated HPV-associated carcinomas based on morphology and immunophenotype. There were no significant immunophenotypic differences between ASCs and pure invasive stratified mucin-producing carcinomas with regard to HPV and other markers including p16 expression. Although limited by a small sample size, survival outcomes seemed to be similar between all groups. ASCs should be diagnosed only in the presence of unequivocal malignant glandular and squamous differentiation. The 2 putative glassy cell carcinomas studied did not meet our criteria for ASC and categorizing them as such should be reconsidered.
Chung S, Weber F, Zhong P, Tan CL, Nguyen TN, Beier KT, Hörmann N, Chang WC, Zhang Z, Do JP, Yao S, Krashes MJ, Tasic B, Cetin A, Zeng H, Knight ZA, Luo L, Dan Y.
PMID: 28514446 | DOI: 10.1038/nature22350
In humans and other mammalian species, lesions in the preoptic area of the hypothalamus cause profound sleep impairment, indicating a crucial role of the preoptic area in sleep generation. However, the underlying circuit mechanism remains poorly understood. Electrophysiological recordings and c-Fos immunohistochemistry have shown the existence of sleep-active neurons in the preoptic area, especially in the ventrolateral preoptic area and median preoptic nucleus. Pharmacogenetic activation of c-Fos-labelled sleep-active neurons has been shown to induce sleep. However, the sleep-active neurons are spatially intermingled with wake-active neurons, making it difficult to target the sleep neurons specifically for circuit analysis. Here we identify a population of preoptic area sleep neurons on the basis of their projection target and discover their molecular markers. Using a lentivirus expressing channelrhodopsin-2 or a light-activated chloride channel for retrograde labelling, bidirectional optogenetic manipulation, and optrode recording, we show that the preoptic area GABAergic neurons projecting to the tuberomammillary nucleus are both sleep active and sleep promoting. Furthermore, translating ribosome affinity purification and single-cell RNA sequencing identify candidate markers for these neurons, and optogenetic and pharmacogenetic manipulations demonstrate that several peptide markers (cholecystokinin, corticotropin-releasing hormone, and tachykinin 1) label sleep-promoting neurons. Together, these findings provide easy genetic access to sleep-promoting preoptic area neurons and a valuable entry point for dissecting the sleep control circuit.
Arthurs, JW;Pauli, JL;Palmiter, RD;
PMID: 36898496 | DOI: 10.1016/j.neuroscience.2023.03.003
Many threats activate parabrachial neurons expressing calcitonin gene-related peptide (CGRPPBN) which transmit alarm signals to forebrain regions. Most CGRPPBN neurons also express tachykinin 1 (Tac1), but there are also Tac1-expressing neurons in the PBN that do not express CGRP (Tac1+;CGRP- neurons). Chemogenetic or optogenetic activation of all Tac1PBN neurons in mice elicited many physiological/behavioral responses resembling the activation of CGRPPBN neurons, e.g., anorexia, jumping on a hot plate, avoidance of photostimulation; however, two key responses opposed activation of CGRPPBN neurons. Activating Tac1PBN neurons did not produce conditioned taste aversion and it elicited dynamic escape behaviors rather than freezing. Activating Tac1+;CGRP- neurons, using an intersectional genetic targeting approach, resembles activating all Tac1PBN neurons. These results reveal that activation of Tac1+;CGRP- neurons can suppress some functions attributed to the CGRPPBN neurons, which provides a mechanism to bias behavioral responses to threats.
