McMeekin, LJ;Joyce, KL;Jenkins, LM;Bohannon, BM;Patel, KD;Bohannon, AS;Patel, A;Fox, SN;Simmons, MS;Day, JJ;Kralli, A;Crossman, DK;Cowell, RM;
PMID: 34648866 | DOI: 10.1016/j.neuroscience.2021.10.007
Deficiency in peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) expression or function is implicated in numerous neurological and psychiatric disorders. PGC-1α is required for the expression of genes involved in synchronous neurotransmitter release, axonal integrity, and metabolism, especially in parvalbumin-positive interneurons. As a transcriptional coactivator, PGC-1α requires transcription factors to specify cell-type-specific gene programs; while much is known about these factors in peripheral tissues, it is unclear if PGC-1α utilizes these same factors in neurons. Here, we identified putative transcription factors controlling PGC-1α-dependent gene expression in the brain using bioinformatics, and then validated the role of the top candidate in a knockout mouse model. We transcriptionally profiled cells overexpressing PGC-1α and searched for over-represented binding motifs in the promoters of upregulated genes. Binding sites of the estrogen-related receptor (ERR) family of transcription factors were enriched and blockade of ERRα attenuated PGC-1α-mediated induction of mitochondrial and synaptic genes in cell culture. Localization in the mouse brain revealed enrichment of ERRα expression in parvalbumin-expressing neurons with tight correlation of expression with PGC-1α across brain regions. In ERRα null mice, PGC-1α-dependent genes were reduced in multiple regions, including neocortex, hippocampus, and cerebellum, though not to the extent observed in PGC-1α null mice. Behavioral assessment revealed ambulatory hyperactivity in response to amphetamine and impairments in sensorimotor gating without the overt motor impairment characteristic of PGC-1α null mice. These data suggest that ERRα is required for normal levels of expression of PGC-1α-dependent genes in neurons, but that additional factors may be involved in their regulation. Significance statement The transcription factors with which PGC-1α interacts determine specificity of the transcriptional program it drives across cell populations, but those mediating its functions in parvalbumin-expressing neurons are unknown. Relative to other PGC-1α-interacting transcription factors, ERRα is enriched in parvalbumin-expressing neurons and shows robust spatial and temporal correlation with PGC-1α expression throughout the brain. ERRα is also necessary for PGC-1α-dependent transcription both in vitro and in vivo for metabolic and neuronal transcripts. These data suggest that ERRα is an important player in cell-specific PGC-1α-dependent transcription in the CNS and may play a role in regulating parvalbumin-expressing neuron maturation and function.
Journal of Neuroendocrinology
He, J;Yan, J;Zha, X;Ding, X;Zhang, Y;Lu, Z;Xu, X;
| DOI: 10.1111/jne.13195
Sex differences in emotional behaviors and affective disorders have been widely noted, of which sexually dimorphic secretion of gonadal steroid hormones such as estrogen is suspected to play a role. However, the underlying neural mechanisms remain poorly understood. We noted that the expression of estrogen receptor 2 (Esr2, or ERβ), a key mediator of estrogen signaling in the brain, was enriched in the dorsal raphe nucleus (DRN), a region involved in emotion regulation. To test whether DRN Esr2 expression confers sex-specific susceptibility or vulnerability in emotional behaviors, we generated a conditional allele of Esr2 that allowed for site-specific deletion of Esr2 in DRN via local injection of Cre-expressing viruses. DRN-specific Esr2 deletion mildly increased anxiety behaviors in females, as shown by decreased time spent in the center zone of an open field in knockout females. By contrast, DRN Esr2 deletion had no effects on anxiety levels in males, as demonstrated by knockout males spending comparable time in the center zone of an open field and open arms of an elevated-plus maze. Furthermore, in the tail suspension test, DRN Esr2 deletion reduced immobility, a depression-like behavior, in a male-biased manner. Together these results reveal sex-specific functions of DRN Esr2 in regulating emotional behaviors and suggest targeted manipulation of DRN Esr2 signaling as a potential therapeutic strategy to treat sex-biased affective disorders.
Journal of Neuroendocrinology
Cara, A;Henson, E;Beekly, B;Elias, C;
| DOI: 10.1111/jne.13063
Androgens are steroid hormones that play a critical role in brain development and sexual maturation by acting upon both androgen receptors (AR), and estrogen receptors (ERα/β) after aromatization. The contribution of estrogens from aromatized androgens in brain development and the central regulation of metabolism, reproduction, and behavior is well defined, but the role of androgens acting on AR has been unappreciated. Here we map the sex specific expression of _Ar_ in the adult and developing mouse brain. Postnatal days (PND) 12 and 21 were used to target a critical window of prepubertal development. Consistent with previous literature in adults, sex-specific differences in _Ar_ expression were most profound in the bed nucleus of the stria terminalis (BST), medial amygdala (MEA), and medial preoptic area (MPO). _Ar_ expression was also high in these areas in PND 12 and 21 of both sexes. In addition, we describe extra-hypothalamic and extra-limbic areas which show moderate, consistent, and similar _Ar_ expression in both sexes at both prepubertal time points. Briefly, _Ar_ expression was observed in olfactory areas of the cerebral cortex, in the hippocampus, several thalamic nuclei, and cranial nerve nuclei involved in autonomic sensory and motor function. To further characterize forebrain populations of _Ar_ expressing neurons and determine whether they also coexpress estrogen receptors, we examined expression of _Ar_, _Esr1_, and _Esr2_ in prepubertal mice in selected nuclei. We found populations of neurons in the BST, MEA, and MPO that coexpress _Ar_, but not _Esr1_ or _Esr2_, while others express a combination of the three receptors. Our findings indicate that various brain areas express _Ar_ during prepubertal development and may play an important role in female neuronal development and physiology.
Kanaya M, Higo S, Ozawa H
PMID: 31877966 | DOI: 10.3390/ijms21010115
Estrogens play an essential role in multiple physiological functions in the brain, including reproductive neuroendocrine, learning and memory, and anxiety-related behaviors. To determine these estrogen functions, many studies have tried to characterize neurons expressing estrogen receptors known as ER? and ER?. However, the characteristics of ER?-expressing neurons in the rat brain still remain poorly understood compared to that of ER?-expressing neurons. The main aim of this study is to determine the neurochemical characteristics of ER?-expressing neurons in the rat hypothalamus using RNAscope in situ hybridization (ISH) combined with immunofluorescence. Strong Esr2 signals were observed especially in the anteroventral periventricular nucleus (AVPV), bed nucleus of stria terminalis, hypothalamic paraventricular nucleus (PVN), supraoptic nucleus, and medial amygdala, as previously reported. RNAscope ISH with immunofluorescence revealed that more than half of kisspeptin neurons in female AVPV expressed Esr2, whereas few kisspeptin neurons were found to co-express Esr2 in the arcuate nucleus. In the PVN, we observed a high ratio of Esr2 co-expression in arginine-vasopressin neurons and a low ratio in oxytocin and corticotropin-releasing factor neurons. The detailed neurochemical characteristics of ER?-expressing neurons identified in the current study can be very essential to understand the estrogen signaling via ER?.
Lavertu-Jolin, M;Chattopadhyaya, B;Chehrazi, P;Carrier, D;Wünnemann, F;Leclerc, S;Dumouchel, F;Robertson, D;Affia, H;Saba, K;Gopal, V;Patel, AB;Andelfinger, G;Pineyro, G;Di Cristo, G;
PMID: 37131076 | DOI: 10.1038/s41380-023-02085-0
While persistence of fear memories is essential for survival, a failure to inhibit fear in response to harmless stimuli is a feature of anxiety disorders. Extinction training only temporarily suppresses fear memory recovery in adults, but it is highly effective in juvenile rodents. Maturation of GABAergic circuits, in particular of parvalbumin-positive (PV+) cells, restricts plasticity in the adult brain, thus reducing PV+ cell maturation could promote the suppression of fear memories following extinction training in adults. Epigenetic modifications such as histone acetylation control gene accessibility for transcription and help couple synaptic activity to changes in gene expression. Histone deacetylase 2 (Hdac2), in particular, restrains both structural and functional synaptic plasticity. However, whether and how Hdac2 controls the maturation of postnatal PV+ cells is not well understood. Here, we show that PV+- cell specific Hdac2 deletion limits spontaneous fear memory recovery in adult mice, while enhancing PV+ cell bouton remodeling and reducing perineuronal net aggregation around PV+ cells in prefrontal cortex and basolateral amygdala. Prefrontal cortex PV+ cells lacking Hdac2, show reduced expression of Acan, a critical perineuronal net component, which is rescued by Hdac2 re-expression. Pharmacological inhibition of Hdac2 before extinction training is sufficient to reduce both spontaneous fear memory recovery and Acan expression in wild-type adult mice, while these effects are occluded in PV+-cell specific Hdac2 conditional knockout mice. Finally, a brief knock-down of Acan expression mediated by intravenous siRNA delivery before extinction training but after fear memory acquisition is sufficient to reduce spontaneous fear recovery in wild-type mice. Altogether, these data suggest that controlled manipulation of PV+ cells by targeting Hdac2 activity, or the expression of its downstream effector Acan, promotes the long-term efficacy of extinction training in adults.
Baho E, Chattopadhyaya B, Lavertu-Jolin M, Mazziotti R, Awad PN, Chehrazi P, Groleau M, Jahannault-Talignani C, Vaucher E, Ango F, Pizzorusso T, Baroncelli L, Di Cristo G.
PMID: 30936240 | DOI: 10.1523/JNEUROSCI.2881-18.2019
By virtue of their extensive axonal arborisation and perisomatic synaptic targeting, cortical inhibitory Parvalbumin (PV) cells strongly regulate principal cell output and plasticity and modulate experience-dependent refinement of cortical circuits during development. An interesting aspect of PV cell connectivity is its prolonged maturation time course, which is completed only by end of adolescence. The p75 neurotrophin receptor (p75NTR) regulates numerous cellular functions, however its role on cortical circuit development and plasticity remains elusive, mainly because localizing p75NTR expression with cellular and temporal resolution has been challenging.By using RNAscope and a modified version of the Proximity Ligation Assay, we found that p75NTR expression in PV cells decreases between the second and fourth postnatal week, at a time when PV cell synapse numbers increase dramatically. Conditional knockout of p75NTR in single PV neurons in vitro and in PV cell networks in vivo causes precocious formation of PV cell perisomatic innervation and perineural nets around PV cell somata, therefore suggesting that p75NTR expression modulates the timing of maturation of PV cell connectivity in the adolescent cortex.Remarkably, we found that PV cells still express p75NTR in adult mouse cortex of both sexes and that its activation is sufficient to destabilize PV cell connectivity and to restore cortical plasticity following monocular deprivation in vivo. Altogether, our results show that p75NTR activation dynamically regulates PV cell connectivity, and represents a novel tool to foster brain plasticity in adults.SIGNIFICANCE STATEMENTIn the cortex, inhibitory, GABA-releasing neurons control the output and plasticity of excitatory neurons. Within this diverse group, parvalbumin-expressing (PV) cells form the larger inhibitory system. PV cell connectivity develops slowly, reaching maturity only at the end of adolescence, however the mechanisms controlling the timing of its maturation are not well understood. We discovered that the expression of the neurotrophin receptor p75NTR in PV cells inhibits the maturation of their connectivity in a cell autonomous fashion, both in vitro and in vivo and that p75NTR activation in adult PV cells promotes their remodelling and restores cortical plasticity. These results reveal a new p75NTR function in the regulation of the time course of PV cell maturation and in limiting cortical plasticity.
Zahaf, A;Kassoussi, A;Hutteau-Hamel, T;Mellouk, A;Marie, C;Zoupi, L;Tsouki, F;Mattern, C;Bobé, P;Schumacher, M;Williams, A;Parras, C;Traiffort, E;
PMID: 36949062 | DOI: 10.1038/s41467-023-36846-w
Neuroprotective, anti-inflammatory, and remyelinating properties of androgens are well-characterized in demyelinated male mice and men suffering from multiple sclerosis. However, androgen effects mediated by the androgen receptor (AR), have been only poorly studied in females who make low androgen levels. Here, we show a predominant microglial AR expression in demyelinated lesions from female mice and women with multiple sclerosis, but virtually undetectable AR expression in lesions from male animals and men with multiple sclerosis. In female mice, androgens and estrogens act in a synergistic way while androgens drive microglia response towards regeneration. Transcriptomic comparisons of demyelinated mouse spinal cords indicate that, regardless of the sex, androgens up-regulate genes related to neuronal function integrity and myelin production. Depending on the sex, androgens down-regulate genes related to the immune system in females and lipid catabolism in males. Thus, androgens are required for proper myelin regeneration in females and therapeutic approaches of demyelinating diseases need to consider male-female differences.
Wyeth MS, Pelkey KA, Yuan X, Vargish G, Johnston AD, Hunt S, Fang C, Abebe D, Mahadevan V, Fisahn A, Salter MW, McInnes RR, Chittajallu R, McBain CJ.
PMID: 28854365 | DOI: 10.1016/j.celrep.2017.08.017
Although Netos are considered auxiliary subunits critical for kainate receptor (KAR) function, direct evidence for their regulation of native KARs is limited. Because Neto KAR regulation is GluK subunit/Neto isoform specific, such regulation must be determined in cell-type-specific contexts. We demonstrate Neto1/2 expression in somatostatin (SOM)-, cholecystokinin/cannabinoid receptor 1 (CCK/CB1)-, and parvalbumin (PV)-containing interneurons. KAR-mediated excitation of these interneurons is contingent upon Neto1 because kainate yields comparable effects in Neto2 knockouts and wild-types but fails to excite interneurons or recruit inhibition in Neto1 knockouts. In contrast, presynaptic KARs in CCK/CB1 interneurons are dually regulated by both Neto1 and Neto2. Neto association promotes tonic presynaptic KAR activation, dampening CCK/CB1 interneuron output, and loss of this brake in Neto mutants profoundly increases CCK/CB1 interneuron-mediatedinhibition. Our results confirm that Neto1 regulates endogenous somatodendritic KARs in diverse interneurons and demonstrate Neto regulation of presynaptic KARs in mature inhibitory presynaptic terminals.
Acta neuropathologica communications
Davis, SE;Cook, AK;Hall, JA;Voskobiynyk, Y;Carullo, NV;Boyle, NR;Hakim, AR;Anderson, KM;Hobdy, KP;Pugh, DA;Murchison, CF;McMeekin, LJ;Simmons, M;Margolies, KA;Cowell, RM;Nana, AL;Spina, S;Grinberg, LT;Miller, BL;Seeley, WW;Arrant, AE;
PMID: 37118844 | DOI: 10.1186/s40478-023-01571-4
Loss of function progranulin (GRN) mutations are a major autosomal dominant cause of frontotemporal dementia (FTD). Patients with FTD due to GRN mutations (FTD-GRN) develop frontotemporal lobar degeneration with TDP-43 pathology type A (FTLD-TDP type A) and exhibit elevated levels of lysosomal proteins and storage material in frontal cortex, perhaps indicating lysosomal dysfunction as a mechanism of disease. To investigate whether patients with sporadic FTLD exhibit similar signs of lysosomal dysfunction, we compared lysosomal protein levels, transcript levels, and storage material in patients with FTD-GRN or sporadic FTLD-TDP type A. We analyzed samples from frontal cortex, a degenerated brain region, and occipital cortex, a relatively spared brain region. In frontal cortex, patients with sporadic FTLD-TDP type A exhibited similar increases in lysosomal protein levels, transcript levels, and storage material as patients with FTD-GRN. In occipital cortex of both patient groups, most lysosomal measures did not differ from controls. Frontal cortex from a transgenic mouse model of TDP-opathy had similar increases in cathepsin D and lysosomal storage material, showing that TDP-opathy and neurodegeneration can drive these changes independently of progranulin. To investigate these changes in additional FTLD subtypes, we analyzed frontal cortical samples from patients with sporadic FTLD-TDP type C or Pick's disease, an FTLD-tau subtype. All sporadic FTLD groups had similar increases in cathepsin D activity, lysosomal membrane proteins, and storage material as FTD-GRN patients. However, patients with FTLD-TDP type C or Pick's disease did not have similar increases in lysosomal transcripts as patients with FTD-GRN or sporadic FTLD-TDP type A. Based on these data, accumulation of lysosomal proteins and storage material may be a common aspect of end-stage FTLD. However, the unique changes in gene expression in patients with FTD-GRN or sporadic FTLD-TDP type A may indicate distinct underlying lysosomal changes among FTLD subtypes.
Somatostatin Interneurons of the Insula Mediate QR2-Dependent Novel Taste Memory Enhancement
Gould, NL;Kolatt Chandran, S;Kayyal, H;Edry, E;Rosenblum, K;
PMID: 34518366 | DOI: 10.1523/ENEURO.0152-21.2021
Forming long-term memories is crucial for adaptive behavior and survival in changing environments. The molecular consolidation processes which underlie the formation of these long-term memories are dependent on protein synthesis in excitatory and SST-expressing neurons. A centrally important, parallel process to this involves the removal of the memory constraint quinone reductase 2 (QR2), which has been recently shown to enhance memory consolidation for novel experiences in the cortex and hippocampus, via redox modulation. However, it is unknown within which cell type in the cortex removal of QR2 occurs, nor how this affects neuronal function. Here, we use novel taste learning in the mouse anterior insular cortex (aIC) to show that similarly to mRNA translation, QR2 removal occurs in excitatory and SST-expressing neurons. Interestingly, both novel taste and QR2 inhibition reduce excitability specifically within SST, but not excitatory neurons. Furthermore, reducing QR2 expression in SST, but not in PV or excitatory neurons, is sufficient to enhance taste memory. Thus, QR2 mediated intrinsic property changes of SST interneurons in the aIC is a central removable factor to allow novel taste memory formation. This previously unknown involvement of QR2 and SST interneurons in resetting aIC activity hours following learning, describes a molecular mechanism to define cell circuits for novel information. Therefore, the QR2 pathway in SST interneurons provides a fresh new avenue by which to tackle age-related cognitive deficits, while shedding new light onto the functional machinations of long-term memory formation for novel information.
Englund, J;Haikonen, J;Shteinikov, V;Amarilla, SP;Atanasova, T;Shintyapina, A;Ryazantseva, M;Partanen, J;Voikar, V;Lauri, SE;
PMID: 34663781 | DOI: 10.1038/s41398-021-01654-7
Early life stress (ELS) is a well-characterized risk factor for mood and anxiety disorders. GABAergic microcircuits in the amygdala are critically implicated in anxiety; however, whether their function is altered after ELS is not known. Here we identify a novel mechanism by which kainate receptors (KARs) modulate feedforward inhibition in the lateral amygdala (LA) and show that this mechanism is downregulated after ELS induced by maternal separation (MS). Specifically, we show that in control rats but not after MS, endogenous activity of GluK1 subunit containing KARs disinhibit LA principal neurons during activation of cortical afferents. GluK1 antagonism attenuated excitability of parvalbumin (PV)-expressing interneurons, resulting in loss of PV-dependent inhibitory control and an increase in firing of somatostatin-expressing interneurons. Inactivation of Grik1 expression locally in the adult amygdala reduced ongoing GABAergic transmission and was sufficient to produce a mild anxiety-like behavioral phenotype. Interestingly, MS and GluK1-dependent phenotypes showed similar gender specificity, being detectable in male but not female rodents. Our data identify a novel KAR-dependent mechanism for cell-type and projection-specific functional modulation of the LA GABAergic microcircuit and suggest that the loss of GluK1 KAR function contributes to anxiogenesis after ELS.
Cutando, L;Puighermanal, E;Castell, L;Tarot, P;Belle, M;Bertaso, F;Arango-Lievano, M;Ango, F;Rubinstein, M;Quintana, A;Chédotal, A;Mameli, M;Valjent, E;
PMID: 35710984 | DOI: 10.1038/s41593-022-01092-8
The cerebellum, a primary brain structure involved in the control of sensorimotor tasks, also contributes to higher cognitive functions including reward, emotion and social interaction. Although the regulation of these behaviors has been largely ascribed to the monoaminergic system in limbic regions, the contribution of cerebellar dopamine signaling in the modulation of these functions remains largely unknown. By combining cell-type-specific transcriptomics, histological analyses, three-dimensional imaging and patch-clamp recordings, we demonstrate that cerebellar dopamine D2 receptors (D2Rs) in mice are preferentially expressed in Purkinje cells (PCs) and regulate synaptic efficacy onto PCs. Moreover, we found that changes in D2R levels in PCs of male mice during adulthood alter sociability and preference for social novelty without affecting motor functions. Altogether, these findings demonstrate novel roles for D2R in PC function and causally link cerebellar D2R levels of expression to social behaviors.
