Yu, XD;Zhu, Y;Sun, QX;Deng, F;Wan, J;Zheng, D;Gong, W;Xie, SZ;Shen, CJ;Fu, JY;Huang, H;Lai, HY;Jin, J;Li, Y;Li, XM;
PMID: 36446933 | DOI: 10.1038/s41593-022-01200-8
Anxiety-like behaviors in mice include social avoidance and avoidance of bright spaces. Whether these features are distinctly regulated is unclear. We demonstrate that in mice, social and anxiogenic stimuli, respectively, increase and decrease serotonin (5-HT) levels in basal amygdala (BA). In dorsal raphe nucleus (DRN), 5-HT∩vGluT3 neurons projecting to BA parvalbumin (DRN5-HT∩vGluT3-BAPV) and pyramidal (DRN5-HT∩vGluT3-BAPyr) neurons have distinct intrinsic properties and gene expression and respond to anxiogenic and social stimuli, respectively. Activation of DRN5-HT∩vGluT3→BAPV inhibits 5-HT release via GABAB receptors on serotonergic terminals in BA, inducing social avoidance and avoidance of bright spaces. Activation of DRN5-HT∩vGluT3→BA neurons inhibits two subsets of BAPyr neurons via 5-HT1A receptors (HTR1A) and 5-HT1B receptors (HTR1B). Pharmacological inhibition of HTR1A and HTR1B in BA induces avoidance of bright spaces and social avoidance, respectively. These findings highlight the functional significance of heterogenic inputs from DRN to BA subpopulations in the regulation of separate anxiety-related behaviors.
Spencer, C;
| DOI: 10.22215/etd/2022-15217
Melanin-concentrating hormone (MCH) is an orexigenic neuropeptide that acts through its receptor (MCHR1) to promote positive energy balance by increasing food intake and decreasing energy expenditure. MCH has been shown to inhibit dopamine release from the mesocorticolimbic dopamine pathway originating in the ventral tegmental area (VTA), and a hyperdopaminergic state underlies hyperactivity observed in animals lacking MCH or MCHR1. However, it is not known if the inhibitory effect of MCH on dopaminergic tone could be due to direct regulation of dopaminergic VTA neurons. We used a combination of molecular, neuroanatomical, and electrophysiological techniques to assess MCHR1 expression and activation in the VTA. MCH neurons project to the VTA, which comprises nerve terminals that contain MCH and may represent MCH release sites. Consistent with this, we detected MCHR1 expression on major VTA cell types, including those that are dopaminergic, GABAergic, and glutamatergic. Functional MCHR1 activation may regulate dopamine release via two mechanisms, one by acutely and directly inhibiting dopaminergic VTA neurons, and the other by disinhibiting glutamatergic afferents to dopaminergic VTA neurons. While we have not measured dopamine release in this present thesis, we postulate that MCH may acutely suppress dopamine release, while concurrently engaging local glutamatergic signaling to restore dopamine levels. These results signify that the VTA is a novel target for MCH-mediated physiology, including for the maintenance of energy homeostasis
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.
Teng, S;Zhen, F;Wang, L;Schalchli, JC;Simko, J;Chen, X;Jin, H;Makinson, CD;Peng, Y;
PMID: 35961989 | DOI: 10.1038/s41467-022-32461-3
Understanding the neural mechanisms underlying sleep state transitions is a fundamental goal of neurobiology and important for the development of new treatments for insomnia and other sleep disorders. Yet, brain circuits controlling this process remain poorly understood. Here we identify a population of sleep-active glutamatergic neurons in the ventrolateral medulla (VLM) that project to the preoptic area (POA), a prominent sleep-promoting region, in mice. Microendoscopic calcium imaging demonstrate that these VLM glutamatergic neurons display increased activity during the transitions from wakefulness to Non-Rapid Eye Movement (NREM) sleep. Chemogenetic silencing of POA-projecting VLM neurons suppresses NREM sleep, whereas chemogenetic activation of these neurons promotes NREM sleep. Moreover, we show that optogenetic activation of VLM glutamatergic neurons or their projections in the POA initiates NREM sleep in awake mice. Together, our findings uncover an excitatory brainstem-hypothalamic circuit that controls the wake-sleep transitions.
Jin, S;Maddern, XJ;Campbell, EJ;Lawrence, AJ;
PMID: 36038028 | DOI: 10.1016/j.neulet.2022.136858
Projections to the striatum are well-identified. For example, in the ventral striatum, two major inputs to the medial nucleus accumbens shell include the ventral subiculum and basolateral amygdala. However, the chemical phenotype(s) of these projection neurons remain unclear. In this study, we examined amygdalostriatal and corticostriatal connectivity in rats using injections of the retrograde tracer cholera toxin b into the nucleus accumbens shell. To determine the neurotransmitter identity of projection neurons, we combined retrograde tracing with RNAscope in-situ hybridization, using mRNA probes against vesicular transporters associated with glutamatergic (VGluT1 - Slc17a7, VGluT2 - Slc17a6) or GABAergic (VGaT - Slc32a1) neurotransmission. Confocal imaging was used to examine vesicular transporter mRNA expression in the ventral subiculum and basolateral amygdala inputs to the nucleus accumbens shell. Both projections contained mostly VGluT1-expressing neurons. Interestingly, almost a quarter of ventral subiculum to nucleus accumbens shell projections co-expressed VGluT1 and VGluT2 compared to a relatively small number (∼3%) that were co-expressed in basolateral amygdala to nucleus accumbens shell afferents. However, almost a quarter of basolateral amygdala to nucleus accumbens shell projections were VGaT-positive. These findings highlight the diverse proportions of glutamatergic and GABAergic afferents in two major projections to the nucleus accumbens shell and raise important questions for functional studies.
Ito, N;Takatsu, A;Ito, H;Koike, Y;Yoshioka, K;Kamei, Y;Imai, SI;
PMID: 35905718 | DOI: 10.1016/j.celrep.2022.111131
Sarcopenia and frailty are urgent socio-economic problems worldwide. Here we demonstrate a functional connection between the lateral hypothalamus (LH) and skeletal muscle through Slc12a8, a recently identified nicotinamide mononucleotide transporter, and its relationship to sarcopenia and frailty. Slc12a8-expressing cells are mainly localized in the LH. LH-specific knockdown of Slc12a8 in young mice decreases activity-dependent energy and carbohydrate expenditure and skeletal muscle functions, including muscle mass, muscle force, intramuscular glycolysis, and protein synthesis. LH-specific Slc12a8 knockdown also decreases sympathetic nerve signals at neuromuscular junctions and β2-adrenergic receptors in skeletal muscle, indicating the importance of the LH-sympathetic nerve-β2-adrenergic receptor axis. LH-specific overexpression of Slc12a8 in aged mice significantly ameliorates age-associated decreases in energy expenditure and skeletal muscle functions. Our results highlight an important role of Slc12a8 in the LH for regulation of whole-body metabolism and skeletal muscle functions and provide insights into the pathogenesis of sarcopenia and frailty during aging.
Feng, C;Wang, Y;Zha, X;Cao, H;Huang, S;Cao, D;Zhang, K;Xie, T;Xu, X;Liang, Z;Zhang, Z;
PMID: 35675799 | DOI: 10.1016/j.cmet.2022.05.002
Homeostatic thermogenesis is an essential protective feature of endotherms. However, the specific neuronal types involved in cold-induced thermogenesis remain largely unknown. Using functional magnetic resonance imaging and in situ hybridization, we screened for cold-sensitive neurons and found preprodynorphin (PDYN)-expressing cells in the dorsal medial region of the ventromedial hypothalamus (dmVMH) to be a candidate. Subsequent in vivo calcium recording showed that cold temperature activates dmVMHPdyn neurons, whereas hot temperature suppresses them. In addition, optogenetic activation of dmVMHPdyn neurons increases the brown adipose tissue and core body temperature, heart rate, and blood pressure, whereas optogenetic inhibition shows opposite effects, supporting their role in homeostatic thermogenesis. Furthermore, we found that dmVMHPdyn neurons are linked to known thermoregulatory circuits. Importantly, dmVMHPdyn neurons also show activation during mouse social interaction, and optogenetic inhibition suppresses social interaction and associated hyperthermia. Together, our study describes dual functions of dmVMHPdyn neurons that allow coordinated regulation of body temperature and social behaviors.
Weil, T;Daly, KM;Yarur Castillo, H;Thomsen, MB;Wang, H;Mercau, ME;Hattar, S;Tejeda, H;Fernandez, DC;
PMID: 35687680 | DOI: 10.1126/sciadv.abn3567
Exposure to irregular lighting schedules leads to deficits in affective behaviors. The retino-recipient perihabenular nucleus (PHb) of the dorsal thalamus has been shown to mediate these effects in mice. However, the mechanisms of how light information is processed within the PHb remains unknown. Here, we show that the PHb contains a distinct cluster of GABAergic neurons that receive direct retinal input. These neurons are part of a larger inhibitory network composed of the thalamic reticular nucleus and zona incerta, known to modulate thalamocortical communication. In addition, PHbGABA neurons locally modulate excitatory-relay neurons, which project to limbic centers. Chronic exposure to irregular light-dark cycles alters photo-responsiveness and synaptic output of PHbGABA neurons, disrupting daily oscillations of genes associated with inhibitory and excitatory PHb signaling. Consequently, selective and chronic PHbGABA manipulation results in mood alterations that mimic those caused by irregular light exposure. Together, light-mediated disruption of PHb inhibitory networks underlies mood deficits.
Jeon, H;Lee, H;Kwon, DH;Kim, J;Tanaka-Yamamoto, K;Yook, JS;Feng, L;Park, HR;Lim, YH;Cho, ZH;Paek, SH;Kim, J;
PMID: 35235786 | DOI: 10.1016/j.celrep.2022.110439
The subthalamic nucleus (STN) controls psychomotor activity and is an efficient therapeutic deep brain stimulation target in individuals with Parkinson's disease. Despite evidence indicating position-dependent therapeutic effects and distinct functions within the STN, the input circuit and cellular profile in the STN remain largely unclear. Using neuroanatomical techniques, we construct a comprehensive connectivity map of the indirect and hyperdirect pathways in the mouse STN. Our circuit- and cellular-level connectivities reveal a topographically graded organization with three types of indirect and hyperdirect pathways (external globus pallidus only, STN only, and collateral). We confirm consistent pathways into the human STN by 7 T MRI-based tractography. We identify two functional types of topographically distinct glutamatergic STN neurons (parvalbumin [PV+/-]) with synaptic connectivity from indirect and hyperdirect pathways. Glutamatergic PV+ STN neurons contribute to burst firing. These data suggest a complex interplay of information integration within the basal ganglia underlying coordinated movement control and therapeutic effects.
Involvement of Scratch2 in GalR1-mediated depression-like behaviors in the rat ventral periaqueductal gray
Proceedings of the National Academy of Sciences of the United States of America
Yang, Y;Li, Y;Liu, B;Li, C;Liu, Z;Deng, J;Luo, H;Li, X;Wu, J;Li, H;Wang, CY;Zhao, M;Wu, H;Lallemend, F;Svenningsson, P;Hökfelt, TGM;Xu, ZD;
PMID: 34108238 | DOI: 10.1073/pnas.1922586118
Galanin receptor1 (GalR1) transcript levels are elevated in the rat ventral periaqueductal gray (vPAG) after chronic mild stress (CMS) and are related to depression-like behavior. To explore the mechanisms underlying the elevated GalR1 expression, we carried out molecular biological experiments in vitro and in animal behavioral experiments in vivo. It was found that a restricted upstream region of the GalR1 gene, from -250 to -220, harbors an E-box and plays a negative role in the GalR1 promoter activity. The transcription factor Scratch2 bound to the E-box to down-regulate GalR1 promoter activity and lower expression levels of the GalR1 gene. The expression of Scratch2 was significantly decreased in the vPAG of CMS rats. Importantly, local knockdown of Scratch2 in the vPAG caused elevated expression of GalR1 in the same region, as well as depression-like behaviors. RNAscope analysis revealed that GalR1 mRNA is expressed together with Scratch2 in both GABA and glutamate neurons. Taking these data together, our study further supports the involvement of GalR1 in mood control and suggests a role for Scratch2 as a regulator of depression-like behavior by repressing the GalR1 gene in the vPAG.
Ventral pallidum DRD3 potentiates a pallido-habenular circuit driving accumbal dopamine release and cocaine seeking
Pribiag, H;Shin, S;Wang, EH;Sun, F;Datta, P;Okamoto, A;Guss, H;Jain, A;Wang, XY;De Freitas, B;Honma, P;Pate, S;Lilascharoen, V;Li, Y;Lim, BK;
PMID: 34048697 | DOI: 10.1016/j.neuron.2021.05.002
Drugs of abuse induce persistent remodeling of reward circuit function, a process thought to underlie the emergence of drug craving and relapse to drug use. However, how circuit-specific, drug-induced molecular and cellular plasticity can have distributed effects on the mesolimbic dopamine reward system to facilitate relapse to drug use is not fully elucidated. Here, we demonstrate that dopamine receptor D3 (DRD3)-dependent plasticity in the ventral pallidum (VP) drives potentiation of dopamine release in the nucleus accumbens during relapse to cocaine seeking after abstinence. We show that two distinct VP DRD3+ neuronal populations projecting to either the lateral habenula (LHb) or the ventral tegmental area (VTA) display different patterns of activity during drug seeking following abstinence from cocaine self-administration and that selective suppression of elevated activity or DRD3 signaling in the LHb-projecting population reduces drug seeking. Together, our results uncover how circuit-specific DRD3-mediated plasticity contributes to the process of drug relapse.
Cascade diversification directs generation of neuronal diversity in the hypothalamus
Zhang, YH;Xu, M;Shi, X;Sun, XL;Mu, W;Wu, H;Wang, J;Li, S;Su, P;Gong, L;He, M;Yao, M;Wu, QF;
PMID: 33887179 | DOI: 10.1016/j.stem.2021.03.020
The hypothalamus contains an astounding heterogeneity of neurons that regulate endocrine, autonomic, and behavioral functions. However, its molecular developmental trajectory and origin of neuronal diversity remain unclear. Here, we profile the transcriptome of 43,261 cells derived from Rax+ hypothalamic neuroepithelium to map the developmental landscape of the mouse hypothalamus and trajectory of radial glial cells (RGCs), intermediate progenitor cells (IPCs), nascent neurons, and peptidergic neurons. We show that RGCs adopt a conserved strategy for multipotential differentiation but generate Ascl1+ and Neurog2+ IPCs. Ascl1+ IPCs differ from their telencephalic counterpart by displaying fate bifurcation, and postmitotic nascent neurons resolve into multiple peptidergic neuronal subtypes. Clonal analysis further demonstrates that single RGCs can produce multiple neuronal subtypes. Our study reveals that multiple cell types along the lineage hierarchy contribute to fate diversification of hypothalamic neurons in a stepwise fashion, suggesting a cascade diversification model that deconstructs the origin of neuronal diversity.