Caprioli D, Venniro M, Zhang M, Bossert JM, Warren BL, Hope BT, Shaham Y.
PMID: 28123032 | DOI: 10.1523/JNEUROSCI.3091-16.2017
Abstract
We recently developed a rat model of incubation of methamphetamine craving after choice-based voluntary abstinence. Here, we studied the role of dorsolateral striatum (DLS) and dorsomedial striatum (DMS) in this incubation. We trained rats to self-administer palatable food pellets (6 d, 6 h/d) and methamphetamine (12 d, 6 h/d). We then assessed relapse to methamphetamine seeking under extinction conditions after 1 and 21 abstinence days. Between tests, the rats underwent voluntary abstinence (using a discrete choice procedure between methamphetamine and food; 20 trials/d) for 19 d. We used in situ hybridization to measure the colabeling of the activity marker Fos with Drd1 and Drd2 in DMS and DLS after the tests. Based on the in situ hybridization colabeling results, we tested the causal role of DMS D1 and D2family receptors, and DMS neuronal ensembles in "incubated" methamphetamine seeking, using selective dopamine receptor antagonists (SCH39166 or raclopride) and the Daun02 chemogenetic inactivation procedure, respectively. Methamphetamine seeking was higher after 21 d of voluntary abstinence than after 1 d (incubation of methamphetamine craving). The incubated response was associated with increased Fos expression in DMS but not in DLS; Fos was colabeled with both Drd1 and Drd2 DMS injections of SCH39166 or raclopride selectively decreased methamphetamine seeking after 21 abstinence days. In Fos-lacZ transgenic rats, selective inactivation of relapse test-activated Fos neurons in DMS on abstinence day 18 decreased incubated methamphetamine seeking on day 21. Results demonstrate a role of DMS dopamine D1 and D2 receptors in the incubation of methamphetamine craving after voluntary abstinence and that DMS neuronal ensembles mediate this incubation.
SIGNIFICANCE STATEMENT:
In human addicts, abstinence is often self-imposed and relapse can be triggered by exposure to drug-associated cues that induce drug craving. We recently developed a rat model of incubation of methamphetamine craving after choice-based voluntary abstinence. Here, we used classical pharmacology, in situ hybridization, immunohistochemistry, and the Daun02 inactivation procedure to demonstrate a critical role of dorsomedial striatum neuronal ensembles in this new form of incubation of drug craving.
Bernanke, A;Burnette, E;Murphy, J;Hernandez, N;Zimmerman, S;Walker, QD;Wander, R;Sette, S;Reavis, Z;Francis, R;Armstrong, C;Risher, ML;Kuhn, C;
PMID: 34898621 | DOI: 10.1371/journal.pone.0260577
Females are more affected by psychiatric illnesses including eating disorders, depression, and post-traumatic stress disorder than males. However, the neural mechanisms mediating these sex differences are poorly understood. Animal models can be useful in exploring such neural mechanisms. Conditioned taste aversion (CTA) is a behavioral task that assesses how animals process the competition between associated reinforcing and aversive stimuli in subsequent task performance, a process critical to healthy behavior in many domains. The purpose of the present study was to identify sex differences in this behavior and associated neural responses. We hypothesized that females would value the rewarding stimulus (Boost ) relative to the aversive stimulus (LiCl) more than males in performing CTA. We evaluated behavior (Boost intake, LiCl-induced behaviors, ultrasonic vocalizations (USVs), CTA performance) and Fos activation in relevant brain regions after the acute stimuli [acute Boost (AB), acute LiCl (AL)] and the context-only task control (COT), Boost only task (BOT) and Boost -LiCl task (BLT). Acutely, females drank more Boost than males but showed similar aversive behaviors after LiCl. Females and males performed CTA similarly. Both sexes produced 55 kHz USVs anticipating BOT and inhibited these calls in the BLT. However, more females emitted both 22 kHz and 55 kHz USVs in the BLT than males: the latter correlated with less CTA. Estrous cycle stage also influenced 55 kHz USVs. Fos responses were similar in males and females after AB or AL. Females engaged the gustatory cortex and ventral tegmental area (VTA) more than males during the BOT and males engaged the amygdala more than females in both the BOT and BLT. Network analysis of correlated Fos responses across brain regions identified two unique networks characterizing the BOT and BLT, in both of which the VTA played a central role. In situ hybridization with RNAscope identified a population of D1-receptor expressing cells in the CeA that responded to Boost and D2 receptor-expressing cells that responded to LiCl. The present study suggests that males and females differentially process the affective valence of a stimulus to produce the same goal-directed behavior.
Tu, HQ;Li, S;Xu, YL;Zhang, YC;Li, PY;Liang, LY;Song, GP;Jian, XX;Wu, M;Song, ZQ;Li, TT;Hu, HB;Yuan, JF;Shen, XL;Li, JN;Han, QY;Wang, K;Zhang, T;Zhou, T;Li, AL;Zhang, XM;Li, HY;
PMID: 37262147 | DOI: 10.1126/science.abm1962
The suprachiasmatic nucleus (SCN) drives circadian clock coherence through intercellular coupling, which is resistant to environmental perturbations. We report that primary cilia are required for intercellular coupling among SCN neurons to maintain the robustness of the internal clock in mice. Cilia in neuromedin S-producing (NMS) neurons exhibit pronounced circadian rhythmicity in abundance and length. Genetic ablation of ciliogenesis in NMS neurons enabled a rapid phase shift of the internal clock under jet-lag conditions. The circadian rhythms of individual neurons in cilia-deficient SCN slices lost their coherence after external perturbations. Rhythmic cilia changes drive oscillations of Sonic Hedgehog (Shh) signaling and clock gene expression. Inactivation of Shh signaling in NMS neurons phenocopied the effects of cilia ablation. Thus, cilia-Shh signaling in the SCN aids intercellular coupling.
Osteoarthritis and cartilage
Jiang, Y;
PMID: 34801671 | DOI: 10.1016/j.joca.2021.11.009
This year in review on osteoarthritis biology summarizes a series of research articles published between the 2020 and 2021 Osteoarthritis Research Society International (OARSI) World Congress. Research hightlights were selected and discussed based on the new discoveries of OA's cellular molecular mechanism, anatomical signatures, potential therapeutic targets, and regenerative therapy. The recently developed potential therapeutic targets are summarized, and the research focuses on TGFβ and WNT signaling in joint tissue homeostasis, joint aging and the dynamic of synolytics in OA joint, and the roles of TRP2, LDHA, OSCAR in cartilage homeostasis and OA joints are highlighted. Subsquencially, new anatomical structures and OA features are introduced, such as synovitis-induced venous portal circulation, horiozontal fissures between cartilage and subchondral bone, the cellular derivation of osteophytes formation, OA subtypes, and subchondral remodeling and pain biology. Then, research on the possibility of tissue regeneration in OA joints are discussed; skeletal stem cells in OA cartilage regeneration, and preclinical results of regenerative therapy for meniscus tear and osteochondral tissue morphoghesis are included. At last, the clinical evidence of the importance of delivery site of bone marrow stem cells for OA treatment is discussed. These findings represent advances in our understanding of OA pathophysiology.
Liu Y, Feng J, Li J, Zhao H, Ho TV, Chai Y.
PMID: 26293299
Coordination between the Hertwig’s Epithelial Root Sheath (HERS) and apical papilla (AP) is crucial for proper tooth root development. The Hedgehog (Hh) signaling pathway and Nfic are both involved in tooth root development, however their relationship has yet to be elucidated. Here we establish a time course of mouse molar root development by histological staining of sections and demonstrate that Hh signaling is active before and during root development in the AP and HERS using Gli1 reporter mice. The proper pattern of Hh signaling activity in the AP is critical for the proliferation of dental mesenchymal cells, because either inhibition with Hh inhibitors or constitutive activation of Hh signaling activity in transgenic mice leads to decreased proliferation in the AP and shorter roots. Moreover, Hh activity is elevated in Nfic-/- mice, a root defect model, whereas RNA sequencing and in situ hybridization show that Hh attenuator Hhip is down-regulated. ChIP and RNAscope analyses suggest that Nfic binds to the promoter region of Hhip. Treatment of Nfic-/- mice with Hh inhibitor partially restores cell proliferation, AP growth and root development. Taken together, our results demonstrate that an Nfic-Hhip-Hh signaling pathway is critical for apical papilla growth and proper root formation. This discovery provides insight into the molecular mechanisms regulating tooth root development.
Al-Hasani R, McCall JG, Shin G, Gomez AM, Schmitz GP, Bernardi JM, Pyo CO, Park SI, Marcinkiewcz CM, Crowley NA, Krashes MJ, Lowell BB, Kash TL, Rogers JA, Bruchas MR.
PMID: 26335648 | DOI: 10.1016/j.neuron.2015.08.019
The nucleus accumbens (NAc) and the dynorphinergic system are widely implicated in motivated behaviors. Prior studies have shown that activation of the dynorphin-kappa opioid receptor (KOR) system leads to aversive, dysphoria-like behavior. However, the endogenous sources of dynorphin in these circuits remain unknown. We investigated whether dynorphinergic neuronal firing in the NAc is sufficient to induce aversive behaviors. We found that photostimulation of dynorphinergic cells in the ventral NAc shell elicits robust conditioned and real-time aversive behavior via KOR activation, and in contrast, photostimulation of dorsal NAc shell dynorphin cells induced a KOR-mediated place preference and was positively reinforcing. These results show previously unknown discrete subregions of dynorphin-containing cells in the NAc shell that selectively drive opposing behaviors. Understanding the discrete regional specificity by which NAc dynorphinerigic cells regulate preference and aversion provides insight into motivated behaviors that are dysregulated in stress, reward, and psychiatric disease.
von Schimmelmann M, Feinberg PA, Sullivan JM, Ku SM, Badimon A, Duff MK, Wang Z, Lachmann A, Dewell S, Ma'ayan A, Han MH, Tarakhovsky A, Schaefer A.
PMID: 27526204 | DOI: 10.1038/nn.4360
Normal brain function depends on the interaction between highly specialized neurons that operate within anatomically and functionally distinct brain regions. Neuronal specification is driven by transcriptional programs that are established during early neuronal development and remain in place in the adult brain. The fidelity of neuronal specification depends on the robustness of the transcriptional program that supports the neuron type-specific gene expression patterns. Here we show that polycomb repressive complex 2 (PRC2), which supports neuron specification during differentiation, contributes to the suppression of a transcriptional program that is detrimental to adult neuron function and survival. We show that PRC2 deficiency in striatal neurons leads to the de-repression of selected, predominantly bivalent PRC2 target genes that are dominated by self-regulating transcription factors normally suppressed in these neurons. The transcriptional changes in PRC2-deficient neurons lead to progressive and fatal neurodegeneration in mice. Our results point to a key role of PRC2 in protecting neurons against degeneration.
Godino, A;Salery, M;Durand-de Cuttoli, R;Estill, MS;Holt, LM;Futamura, R;Browne, CJ;Mews, P;Hamilton, PJ;Neve, RL;Shen, L;Russo, SJ;Nestler, EJ;
PMID: 36889314 | DOI: 10.1016/j.neuron.2023.02.013
The complex nature of the transcriptional networks underlying addictive behaviors suggests intricate cooperation between diverse gene regulation mechanisms that go beyond canonical-activity-dependent pathways. Here, we implicate in this process a nuclear receptor transcription factor, retinoid X receptor alpha (RXRα), which we initially identified bioinformatically as associated with addiction-like behaviors. In the nucleus accumbens (NAc) of male and female mice, we show that although its own expression remains unaltered after cocaine exposure, RXRα controls plasticity- and addiction-relevant transcriptional programs in both dopamine receptor D1- and D2-expressing medium spiny neurons, which in turn modulate intrinsic excitability and synaptic activity of these NAc cell types. Behaviorally, bidirectional viral and pharmacological manipulation of RXRα regulates drug reward sensitivity in both non-operant and operant paradigms. Together, this study demonstrates a key role for NAc RXRα in promoting drug addiction and paves the way for future studies of rexinoid signaling in psychiatric disease states.
Yang N, Leung EL, Liu C, Li L, Eguether T, Jun Yao XJ, Jones EC, Norris DA, Liu A, Clark RA, Roop DR, Pazour GJ, Shroyer KR, Chen J.
PMID: 28459465 | DOI: 10.1038/onc.2017.117
Inturned (INTU), a cilia and planar polarity effector, performs prominent ciliogenic functions during morphogenesis, such as in the skin. INTU is expressed in adult tissues but its role in tissue maintenance is unknown. Here, we report that the expression of the INTU gene is aberrantly elevated in human basal cell carcinoma (BCC), coinciding with increased primary cilia formation and activated hedgehog (Hh) signaling. Disrupting Intu in an oncogenic mutant Smo (SmoM2)-driven BCC mouse model prevented the formation of BCC through suppressing primary cilia formation and Hh signaling, suggesting that Intu performs a permissive role during BCC formation. INTU is essential for intraflagellar transport A complex assembly during ciliogenesis. To further determine whether Intu is directly involved in the activation of Hh signaling downstream of ciliogenesis, we examined the Hh signaling pathway in mouse embryonic fibroblasts, which readily responds to the Hh pathway activation. Depleting Intu blocked Smo agonist-induced Hh pathway activation, whereas the expression of Gli2ΔN, a constitutively active Gli2, restored Hh pathway activation in Intu-deficient cells, suggesting that INTU functions upstream of Gli2 activation. In contrast, overexpressing Intu did not promote ciliogenesis or Hh signaling. Taken together, data obtained from this study suggest that INTU is indispensable during BCC tumorigenesis and that its aberrant upregulation is likely a prerequisite for primary cilia formation during Hh-dependent tumorigenesis.
Kim, JS;Williams, KC;Kirkland, RA;Schade, R;Freeman, KG;Cawthon, CR;Rautmann, AW;Smith, JM;Edwards, GL;Glenn, TC;Holmes, PV;de Lartigue, G;de La Serre, CB;
PMID: 37380023 | DOI: 10.1016/j.molmet.2023.101764
Obesity is associated with deficits in reward which have been linked to compensatory overeating. The vagus nerve is a direct neural pathway that conveys post-ingestive feedback from the gut to the brain, including the reward regions, and vagal activation causes stereotypical reward behaviors. Chronic high fat (HF) feeding alters vagal signaling potentially dampening food-associated reward. Microbiota composition changes rapidly with HF feeding, and a HF-type microbiota is sufficient to alter vagal structure and function. However, whether microbiota-driven alterations in vagal signaling affect host appetitive feeding behavior is unknown. Here, we investigate if microbiota composition modulates reward signaling and assess the role of the vagus in mediating microbiota to brain communication. Male germ-free Fisher rats were colonized with gastrointestinal contents from chow (low fat (LF) ConvLF) or HF (ConvHF) fed rats. Following colonization, ConvHF rats consumed significantly more food than ConvLF animals. ConvHF rats displayed lower feeding-induced extracellular DOPAC levels (a metabolite of dopamine) in the Nucleus Accumbens (NAc) as well as reduced motivation for HF foods compared to ConvLF rats. Dopamine receptor 2 (DDR2) expression levels in the NAc were also significantly lower in ConvHF animals. Similar deficits were observed in conventionally raised HF fed rats, showing that diet-driven alteration in reward can be initiated via microbiota. Selective gut to brain deafferentation restored DOPAC levels, DRD2 expression, and motivational drive in ConvHF rats. We concluded from these data that a HF-type microbiota is sufficient to alter appetitive feeding behavior and that bacteria to reward communication is mediated by the vagus nerve.
Reiner, BC;Zhang, Y;Stein, LM;Perea, ED;Arauco-Shapiro, G;Ben Nathan, J;Ragnini, K;Hayes, MR;Ferraro, TN;Berrettini, WH;Schmidt, HD;Crist, RC;
PMID: 36075888 | DOI: 10.1038/s41398-022-02135-1
Opioid exposure is known to cause transcriptomic changes in the nucleus accumbens (NAc). However, no studies to date have investigated cell type-specific transcriptomic changes associated with volitional opioid taking. Here, we use single nucleus RNA sequencing (snRNAseq) to comprehensively characterize cell type-specific alterations of the NAc transcriptome in rats self-administering morphine. One cohort of male Brown Norway rats was injected with acute morphine (10 mg/kg, i.p.) or saline. A second cohort of rats was allowed to self-administer intravenous morphine (1.0 mg/kg/infusion) for 10 consecutive days. Each morphine-experienced rat was paired with a yoked saline control rat. snRNAseq libraries were generated from NAc punches and used to identify cell type-specific gene expression changes associated with volitional morphine taking. We identified 1106 differentially expressed genes (DEGs) in the acute morphine group, compared to 2453 DEGs in the morphine self-administration group, across 27 distinct cell clusters. Importantly, we identified 1329 DEGs that were specific to morphine self-administration. DEGs were identified in novel clusters of astrocytes, oligodendrocytes, and D1R- and D2R-expressing medium spiny neurons in the NAc. Cell type-specific DEGs included Rgs9, Celf5, Oprm1, and Pde10a. Upregulation of Rgs9 and Celf5 in D2R-expressing neurons was validated by RNAscope. Approximately 85% of all oligodendrocyte DEGs, nearly all of which were associated with morphine taking, were identified in two subtypes. Bioinformatic analyses identified cell type-specific upstream regulatory mechanisms of the observed transcriptome alterations and downstream signaling pathways, including both novel and previously identified molecular pathways. These findings show that volitional morphine taking is associated with distinct cell type-specific transcriptomic changes in the rat NAc and highlight specific striatal cell populations and novel molecular substrates that could be targeted to reduce compulsive opioid taking.
Caprioli D, Venniro M, Zhang M, Bossert JM, Warren BL, Hope BT, Shaham Y.
PMID: 27980115 | DOI: 10.1523/JNEUROSCI.3091-16.2016
We recently developed a rat model of incubation of methamphetamine craving after choice-based voluntary abstinence. Here, we studied the role of dorsolateral and dorsomedial striatum (DLS, DMS) in this incubation.We trained rats to self-administer palatable food pellets (6 days, 6-h/d) and methamphetamine (12 days, 6-h/d). We then assessed relapse to methamphetamine seeking under extinction conditions after 1 and 21 abstinence days. Between tests, the rats underwent voluntary abstinence (using a discrete choice procedure between methamphetamine and food; 20 trials/day) for 19 days. We used in situ hybridization to measure co-labeling of the activity marker Fos with Drd1 and Drd2 in DMS and DLS after the tests. Based on the in situ hybridization co-labeling results, we tested the causal role of DMS D1- and D2-family receptors, and DMS neuronal ensembles in 'incubated' methamphetamine seeking, using selective dopamine receptor antagonists (SCH39166 or raclopride) and the Daun02 chemogenetic inactivation procedure, respectively.Methamphetamine seeking was higher after 21 days of voluntary abstinence than after 1 day (incubation of methamphetamine craving). The 'incubated' response was associated with increased Fos expression in DMS but not DLS; Fos was co-labeled with both Drd1 and Drd2 DMS injections of SCH39166 or raclopride selectively decreased methamphetamine seeking after 21 abstinence days. In Fos-lacZ transgenic rats, selective inactivation of relapse test-activated Fos neurons in DMS on abstinence day 18 decreased incubated methamphetamine seeking on day 21.Results demonstrate a role of DMS dopamine D1 and D2-receptors in incubation of methamphetamine craving after voluntary abstinence and that DMS neuronal ensembles mediate this incubation.
SIGNIFICANCE STATEMENT:
In human addicts, abstinence is often self-imposed and relapse can be triggered by exposure to drug-associated cues that induce drug craving. We recently developed a rat model of incubation of methamphetamine craving after choice-based voluntary abstinence. Here, we used classical pharmacology, in situ hybridization, immunohistochemistry, and the Daun02 inactivation procedure to demonstrate a critical role of dorsomedial striatum neuronal ensembles in this new form of incubation of drug craving.
