Ding, CY;Ding, YT;Ji, H;Wang, YY;Zhang, X;Yin, DM;
PMID: 37147705 | DOI: 10.1186/s13578-023-01032-4
Where the gene is expressed determines the function of the gene. Neuregulin 1 (Nrg1) encodes a tropic factor and is genetically linked with several neuropsychiatry diseases such as schizophrenia, bipolar disorder and depression. Nrg1 has broad functions ranging from regulating neurodevelopment to neurotransmission in the nervous system. However, the expression pattern of Nrg1 at the cellular and circuit levels in rodent brain is not full addressed.Here we used CRISPR/Cas9 techniques to generate a knockin mouse line (Nrg1Cre/+) that expresses a P2A-Cre cassette right before the stop codon of Nrg1 gene. Since Cre recombinase and Nrg1 are expressed in the same types of cells in Nrg1Cre/+ mice, the Nrg1 expression pattern can be revealed through the Cre-reporting mice or adeno-associated virus (AAV) that express fluorescent proteins in a Cre-dependent way. Using unbiased stereology and fluorescence imaging, the cellular expression pattern of Nrg1 and axon projections of Nrg1-positive neurons were investigated.In the olfactory bulb (OB), Nrg1 is expressed in GABAergic interneurons including periglomerular (PG) and granule cells. In the cerebral cortex, Nrg1 is mainly expressed in the pyramidal neurons of superficial layers that mediate intercortical communications. In the striatum, Nrg1 is highly expressed in the Drd1-positive medium spiny neurons (MSNs) in the shell of nucleus accumbens (NAc) that project to substantia nigra pars reticulata (SNr). In the hippocampus, Nrg1 is mainly expressed in granule neurons in the dentate gyrus and pyramidal neurons in the subiculum. The Nrg1-expressing neurons in the subiculum project to retrosplenial granular cortex (RSG) and mammillary nucleus (MM). Nrg1 is highly expressed in the median eminence (ME) of hypothalamus and Purkinje cells in the cerebellum.Nrg1 is broadly expressed in mouse brain, mainly in neurons, but has unique expression patterns in different brain regions.
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
McNulty, CJ;Fallon, IP;Amat, J;Sanchez, RJ;Leslie, NR;Root, DH;Maier, SF;Baratta, MV;
PMID: 36076018 | DOI: 10.1038/s41386-022-01443-w
Stress-linked disorders are more prevalent in women than in men and differ in their clinical presentation. Thus, investigating sex differences in factors that promote susceptibility or resilience to stress outcomes, and the circuit elements that mediate their effects, is important. In male rats, instrumental control over stressors engages a corticostriatal system involving the prelimbic cortex (PL) and dorsomedial striatum (DMS) that prevent many of the sequelae of stress exposure. Interestingly, control does not buffer against stress outcomes in females, and here, we provide evidence that the instrumental controlling response in females is supported instead by the dorsolateral striatum (DLS). Additionally, we used in vivo microdialysis, fluorescent in situ hybridization, and receptor subtype pharmacology to examine the contribution of prefrontal dopamine (DA) to the differential impact of behavioral control. Although both sexes preferentially expressed D1 receptor mRNA in PL GABAergic neurons, there were robust sex differences in the dynamic properties of prefrontal DA during controllable stress. Behavioral control potently attenuated stress-induced DA efflux in males, but not females, who showed a sustained DA increase throughout the entire stress session. Importantly, PL D1 receptor blockade (SCH 23390) shifted the proportion of striatal activity from the DLS to the DMS in females and produced the protective effects of behavioral control. These findings suggest a sex-selective mechanism in which elevated DA in the PL biases instrumental responding towards prefrontal-independent striatal circuitry, thereby eliminating the protective impact of coping with stress.
Porcu, A;Nilsson, A;Booreddy, S;Barnes, SA;Welsh, DK;Dulcis, D;
PMID: 36054362 | DOI: 10.1126/sciadv.abn9867
Seasonal changes in day length (photoperiod) affect numerous physiological functions. The suprachiasmatic nucleus (SCN)-paraventricular nucleus (PVN) axis plays a key role in processing photoperiod-related information. Seasonal variations in SCN and PVN neurotransmitter expression have been observed in humans and animal models. However, the molecular mechanisms by which the SCN-PVN network responds to altered photoperiod is unknown. Here, we show in mice that neuromedin S (NMS) and vasoactive intestinal polypeptide (VIP) neurons in the SCN display photoperiod-induced neurotransmitter plasticity. In vivo recording of calcium dynamics revealed that NMS neurons alter PVN network activity in response to winter-like photoperiod. Chronic manipulation of NMS neurons is sufficient to induce neurotransmitter switching in PVN neurons and affects locomotor activity. Our findings reveal previously unidentified molecular adaptations of the SCN-PVN network in response to seasonality and the role for NMS neurons in adjusting hypothalamic function to day length via a coordinated multisynaptic neurotransmitter switching affecting behavior.
Gene-targeted, CREB-mediated induction of ΔFosB controls distinct downstream transcriptional patterns within D1 and D2 medium spiny neurons
Lardner, C;van der Zee, Y;Estill, M;Kronman, H;Salery, M;Cunningham, A;Godino, A;Parise, E;Kim, J;Neve, R;Shen, L;Hamilton, P;Nestler, E;
| DOI: 10.1016/j.biopsych.2021.06.017
Background The onset and persistence of addiction phenotypes are, in part, mediated by transcriptional mechanisms in the brain that affect gene expression and subsequently neural circuitry. ΔFosB is a transcription factor that accumulates in the nucleus accumbens (NAc) – a brain region responsible for coordinating reward and motivation – after exposure to virtually every known rewarding substance, including cocaine and opioids. ΔFosB has also been shown to directly control gene transcription and behavior downstream of both cocaine and opioid exposure, but with potentially different roles in D1 and D2 medium spiny neurons (MSNs) in NAc. Methods To clarify MSN subtype-specific roles for ΔFosB, and investigate how these coordinate the actions of distinct classes of addictive drugs in NAc, we developed a CRISPR/Cas9-based epigenome editing tool to induce endogenous ΔFosB expression in vivo in the absence of drug exposure. After inducing ΔFosB in D1 or D2 MSNs, or both, we performed RNA-sequencing on bulk male and female NAc tissue (N = 6-8/group). Results We find that ΔFosB induction elicits distinct transcriptional profiles in NAc by MSN subtype and by sex, establishing for the first time that ΔFosB mediates different transcriptional effects in males vs females. We also demonstrate that changes in D1 MSNs, but not in D2 MSNs or both, significantly recapitulate changes in gene expression induced by cocaine self-administration. Conclusions Together, these findings demonstrate the efficacy of a novel molecular tool for studying cell-type-specific transcriptional mechanisms, and shed new light on the activity of ΔFosB, a critical transcriptional regulator of drug addiction.
Zhou, K;Xu, H;Lu, S;Jiang, S;Hou, G;Deng, X;He, M;Zhu, Y;
PMID: 36271048 | DOI: 10.1038/s41467-022-33843-3
The nucleus accumbens (NAc) is critical in mediating reward seeking and is also involved in negative emotion processing, but the cellular and circuitry mechanisms underlying such opposing behaviors remain elusive. Here, using the recently developed AAV1-mediated anterograde transsynaptic tagging technique in mice, we show that NAc neurons receiving basolateral amygdala inputs (NAcBLA) promote positive reinforcement via disinhibiting dopamine neurons in the ventral tegmental area (VTA). In contrast, NAc neurons receiving paraventricular thalamic inputs (NAcPVT) innervate GABAergic neurons in the lateral hypothalamus (LH) and mediate aversion. Silencing the synaptic output of NAcBLA neurons impairs reward seeking behavior, while silencing of NAcPVT or NAcPVT→LH pathway abolishes aversive symptoms of opiate withdrawal. Our results elucidate the afferent-specific circuit architecture of the NAc in controlling reward and aversion.
Frontiers in cellular neuroscience
Giua, G;Lassalle, O;Makrini-Maleville, L;Valjent, E;Chavis, P;Manzoni, OJJ;
PMID: 37323585 | DOI: 10.3389/fncel.2023.1146647
Fragile X syndrome (FXS), resulting from a mutation in the Fmr1 gene, is the most common monogenic cause of autism and inherited intellectual disability. Fmr1 encodes the Fragile X Messenger Ribonucleoprotein (FMRP), and its absence leads to cognitive, emotional, and social deficits compatible with the nucleus accumbens (NAc) dysfunction. This structure is pivotal in social behavior control, consisting mainly of spiny projection neurons (SPNs), distinguished by dopamine D1 or D2 receptor expression, connectivity, and associated behavioral functions. This study aims to examine how FMRP absence differentially affects SPN cellular properties, which is crucial for categorizing FXS cellular endophenotypes.We utilized a novel Fmr1-/y::Drd1a-tdTomato mouse model, which allows in-situ identification of SPN subtypes in FXS mice. Using RNA-sequencing, RNAScope and ex-vivo patch-clamp in adult male mice NAc, we comprehensively compared the intrinsic passive and active properties of SPN subtypes.Fmr1 transcripts and their gene product, FMRP, were found in both SPNs subtypes, indicating potential cell-specific functions for Fmr1. The study found that the distinguishing membrane properties and action potential kinetics typically separating D1- from D2-SPNs in wild-type mice were either reversed or abolished in Fmr1-/y::Drd1a-tdTomato mice. Interestingly, multivariate analysis highlighted the compound effects of Fmr1 ablation by disclosing how the phenotypic traits distinguishing each cell type in wild-type mice were altered in FXS.Our results suggest that the absence of FMRP disrupts the standard dichotomy characterizing NAc D1- and D2-SPNs, resulting in a homogenous phenotype. This shift in cellular properties could potentially underpin select aspects of the pathology observed in FXS. Therefore, understanding the nuanced effects of FMRP absence on SPN subtypes can offer valuable insights into the pathophysiology of FXS, opening avenues for potential therapeutic strategies.
Molecular Neuropsychiatry
Hu X,. Rocco BR, Fee C, Sibille E.
PMID: - | DOI: 10.1159/000495840
Converging evidence suggests that deficits in somatostatin (SST)-expressing neuron signaling contributes to major depressive disorder. Preclinical studies show that enhancing this signaling, specifically at α5 subunit-containing γ-aminobutyric acid subtype A receptors (α5-GABAARs), provides a potential means to overcome low SST neuron function. The cortical microcircuit comprises multiple subtypes of inhibitory γ-aminobutyric acid (GABA) neurons and excitatory pyramidal cells (PYCs). In this study, multilabel fluorescence in situ hybridization was used to characterize α5-GABAAR gene expression in PYCs and three GABAergic neuron subgroups – vasoactive intestinal peptide (VIP)-, SST-, and parvalbumin (PV)-expressing cells – in the human and mouse frontal cortex. Across species, we found the majority of gene expression in PYCs (human: 39.7%; mouse: 54.14%), less abundant expression in PV neurons (human: 20%; mouse: 16.33%), and no expression in VIP neurons (0%). Only human SST cells expressed GABRA5, albeit at low levels (human: 8.3%; mouse: 0%). Together, this localization suggests potential roles for α5-GABAARs within the cortical microcircuit: (1) regulators of PYCs, (2) regulators of PV cell activity across species, and (3) sparse regulators of SST cell inhibition in humans. These results will advance our ability to predict the effects of pharmacological agents targeting α5-GABAARs, which have shown therapeutic potential in preclinical animal models.
Li, K;Shi, Y;Gonye, EC;Bayliss, DA;
PMID: 34732535 | DOI: 10.1523/ENEURO.0212-21.2021
Select neuronal populations display steady rhythmic neuronal firing that provides tonic excitation to drive downstream networks and behaviors. In noradrenergic neurons of the locus coeruleus (LC), circadian neurons of the suprachiasmatic nucleus (SCN), and CO2/H+-activated neurons of the brainstem retrotrapezoid nucleus (RTN), large subthreshold membrane potential oscillations contribute to the pacemaker-like action potential discharge. The oscillations and firing in LC and SCN involve contributions from leak sodium (NALCN) and L-type calcium channels while recent work from RTN suggested an additional pivotal role for a secondary calcium-activated and voltage-gated cationic current sensitive to TRPM4 channel blockers. Here, we tested whether TRPM4 contributes to subthreshold oscillations in mouse LC and SCN. By RNAscope in situ hybridization, Trpm4 transcripts were detected in both cell groups. In whole-cell recordings from acute slice preparations, prominent voltage-dependent membrane potential oscillations were revealed in LC and SCN after blocking action potentials. These oscillations were inhibited by two chemically-distinct blockers of TRPM4, 9-phenanthrol (9-pt) and 4-chloro-2-[[2-(2-chlorophenoxy)acetyl]amino]benzoic acid (CBA). Under whole-cell voltage clamp, inward currents evoked by oscillation voltage waveforms were inhibited in LC by blocking L-type calcium channels and TRPM4. These data implicate TRPM4 in the large subthreshold membrane potential oscillations that underlie tonic action potential discharge in LC and SCN, providing a voltage-dependent and calcium-dependent cationic current to augment the depolarizing inward Na+ and Ca2+ currents previously associated with this distinctive electroresponsive property.
The Journal of Neuroscience, 8 April 2015, 35(14): 5625-5639
Rubio FJ, Liu QR, Li X, Cruz FC, Leão RM, Warren BL, Kambhampati S, Babin KR, McPherson KB, Cimbro R, Bossert JM, Shaham Y, Hope BT.
PMID: 25855177 | DOI: 10.1523/JNEUROSCI.4997-14.2015
Context-induced reinstatement of drug seeking is a well established animal model for assessing the neural mechanisms underlying context-induced drug relapse, a major factor in human drug addiction. Neural activity in striatum has previously been shown to contribute to context-induced reinstatement of heroin, cocaine, and alcohol seeking, but not yet for methamphetamine seeking. In this study, we found that context-induced reinstatement of methamphetamine seeking increased expression of the neural activity marker Fos in dorsal but not ventral striatum. Reversible inactivation of neural activity in dorsolateral but not dorsomedial striatum using the GABA agonists muscimol and baclofen decreased context-induced reinstatement. Based on our previous findings that Fos-expressing neurons play a critical role in conditioned drug effects, we assessed whether context-induced reinstatement was associated with molecular alterations selectively induced within context-activated Fos-expressing neurons. We used fluorescence-activated cell sorting to isolate reinstatement-activated Fos-positive neurons from Fos-negative neurons in dorsal striatum and used quantitative PCR to assess gene expression within these two populations of neurons. Context-induced reinstatement was associated with increased expression of the immediate early genes Fos and FosB and the NMDA receptor subunit gene Grin2a in only Fos-positive neurons. RNAscope in situ hybridization confirmed that Grin2a, as well as Grin2b, expression were increased in only Fos-positive neurons from dorsolateral, but not dorsomedial, striatum. Our results demonstrate an important role of dorsolateral striatum in context-induced reinstatement of methamphetamine seeking and that this reinstatement is associated with unique gene alterations in Fos-expressing neurons.
Cocaine Augments Dopamine Mediated Inhibition of Neuronal Activity in the Dorsal Bed Nucleus of the Stria Terminalis
The Journal of neuroscience : the official journal of the Society for Neuroscience
Melchior, JR;Perez, RE;Salimando, GJ;Luchsinger, JR;Basu, A;Winder, DG;
PMID: 34035141 | DOI: 10.1523/JNEUROSCI.0284-21.2021
The dorsal region of the bed nucleus of the stria terminalis (dBNST) receives substantial dopaminergic input which overlaps with norepinephrine input implicated in stress responses. Using ex vivo fast scan cyclic voltammetry in male C57BL6 mouse brain slices, we demonstrate that electrically stimulated dBNST catecholamine signals are of substantially lower magnitude and have slower uptake rates compared to caudate signals. Dopamine terminal autoreceptor activation inhibited roughly half of the catecholamine transient, and noradrenergic autoreceptor activation produced an ∼30% inhibition. Dopamine transporter blockade with either cocaine or GBR12909 significantly augmented catecholamine signal duration. We optogenetically targeted dopamine terminals in the dBNST of transgenic (TH:Cre) mice of either sex and, using ex vivo whole-cell electrophysiology, we demonstrate that optically stimulated dopamine release induces slow outward membrane currents and an associated hyperpolarization response in a subset of dBNST neurons. These cellular responses had a similar temporal profile to dopamine release, were significantly reduced by the D2/D3 receptor antagonist raclopride, and were potentiated by cocaine. Using in vivo fiber photometry in male C57BL6 mice during training sessions for cocaine conditioned place preference, we show that acute cocaine administration results in a significant inhibition of calcium transient activity in dBNST neurons compared to saline administration. These data provide evidence for a mechanism of dopamine-mediated cellular inhibition in the dBNST and demonstrate that cocaine augments this inhibition while also decreasing net activity in the dBNST in a drug reinforcement paradigm.SIGNIFICANCE STATEMENTThe dorsal bed nucleus of the stria terminalis (dBNST) is a region highly implicated in mediating stress responses, however, the dBNST also receives dopaminergic inputs from classically defined drug reward pathways. Here we used various techniques to demonstrate that dopamine signaling within the dorsal BNST region has inhibitory effects on population activity. We show that cocaine, an abused psychostimulant, augments both catecholamine release and dopamine-mediated cellular inhibition in this region. We also demonstrate that cocaine administration reduces population activity in the dBNST, in vivo Together these data support a mechanism of dopamine-mediated inhibition within the dBNST, providing a means by which drug-induced elevations in dopamine signaling may inhibit dBNST activity to promote drug reward.
Lorsch ZS, Loh YHE, Purushothaman I, Walker DM, Parise EM, Salery M ,Cahill ME, Hodes GE, Pfau ML, Kronman H, Hamilton PJ, Issler O, Labonté B, Symonds AE, Zucker M, Zhang TY, Meaney MJ, Russo SJ, Shen L, Bagot RC, Nestler EJ.
PMID: 29549264 | DOI: 10.1038/s41467-018-03567-4
Most people exposed to stress do not develop depression. Animal models have shown that stress resilience is an active state that requires broad transcriptional adaptations, but how this homeostatic process is regulated remains poorly understood. In this study, we analyze upstream regulators of genes differentially expressed after chronic social defeat stress. We identify estrogen receptor α (ERα) as the top regulator of pro-resilient transcriptional changes in the nucleus accumbens (NAc), a key brain reward region implicated in depression. In accordance with these findings, nuclear ERα protein levels are altered by stress in male and female mice. Further, overexpression of ERα in the NAc promotes stress resilience in both sexes. Subsequent RNA-sequencing reveals that ERα overexpression in NAc reproduces the transcriptional signature of resilience in male, but not female, mice. These results indicate that NAc ERα is an important regulator of pro-resilient transcriptional changes, but with sex-specific downstream targets.
Chen X, Liu Z, Ma C, Ma L, Liu X.
PMID: - | DOI: 10.3389/fnbeh.2019.00110
Parvalbumin (PV) expressing GABAergic interneurons provide large source of GABA to spiny projection neurons (SPNs) in the striatum. However, the roles of PV+ interneurons in the regulation of SPNs in the ventral striatum and emotional states are largely unknown. Here, we investigated whether stimulation of ventral striatal (accumbal) PV+ interneurons would drive emotional valence in mice. We found that during conditioned place preference (CPP) training, activation of accumbal PV+ interneurons evoked place preference while suppressing them resulted in conditioned place aversion (CPA). Activation of PV+interneurons during place conditioning increased Fos expression in SPNs in the direct pathway (dSPNs) and impaired lithium chloride-induced CPA. Activation of dSPNs and SPNs in the indirect pathway (iSPNs) induced CPP and CPA, respectively; conversely, suppression of dSPNs or iSPNs induced CPA or CPP. In addition, activation or suppression of calretinin-expressing (CR) GABAergic interneurons did not induce place preference or aversion. These data suggest that PV+ interneurons can bidirectionally determine the emotional valence through their regulation of accumbal SPN activities and raise the possibility that manipulation of PV+ interneuron activity may have the potential to alter emotional valence and treat related mental disorders.
