*Note: All publications available for PDF download below
1. The Neuroscience of Empathy
In my current research, I am investigating the brain systems that underlie empathy. Empathy can be defined as experiencing or adopting an emotional state that is more appropriate to another's circumstances than your own. Through behavioral studies in mice, we are working to identify the brain circuits that allow us to "feel each other's pain," and the mechanisms by which we might be able to enhance empathy. These studies are currently unpublished (still in the works!)
Related publications (all PDFs available for download below):
Rein & Jones et al, STAR Protocols, 2022
2. Genetics & Autism Spectrum Disorder (ASD)
In my Ph.D., I studied how certain autism-linked gene mutations can affect brain function. More specifically, I focused on synaptic transmission (the way that brain cells communicate) in the prefrontal cortex (PFC) - a brain area important for sociability and high-level cognition. On chromosome 16, there is a section of 27 genes (called 16p11.2) which may be randomly duplicated or deleted. This results in too much or too little of these genes, respectively, and can increase the risk of developing ASD, intellectual disability, epilepsy, and many other conditions. These genetic mutations are fairly common, each affecting ~1 in every 3,500 individuals. However, very little had previously been known about how they affect the brain. Through our studies, we discovered that neurons in the PFC are less active in mice with 16p11.2 deletion, while they are more active in mice with 16p11.2 duplication. Moreover, restoring a homeostatic level of activity in these PFC neurons increased sociability and cognition in both mouse models! Our findings suggest that imbalanced activity of PFC neurons is a core mechanism driving social and cognitive deficits in 16p11.2 deletions & duplications.
Related publications (all PDFs available for download below):
Conrow-Graham et al., Brain, 2022
Rapanelli et al., Molecular Psychiatry, 2022
Rein et al., Neuropharmacology, 2021
Yan & Rein, Molecular Psychiatry, 2021
Wang & Rein et al., Neuropsychopharmacology, 2021
Zhang & Rein et al., Translational Psychiatry, 2021
Rein & Yan, Trends in Neurosciences, 2020
Rein et al., Molecular Psychiatry, 2020
Wang & Rein, Journal of Neuroscience, 2018
3. Modeling Social Behavior in Mice
As a scientist using mice to study social behavior, I believe we must challenge and improve the ways we quantify the many complex features of interaction. While working in my Ph.D., I discovered a concerning problem in the literature: that the most common method for testing social behavior in mice was producing highly inconsistent results across different research labs. Moreover, each lab appeared to be using a different protocol, which appeared to be underlying the different results. This is very problematic for scientific reproducibility. We thus developed a standardized protocol of this test which has robust sensitivity to social deficits in multiple mouse models of autism. I also led the development of a behavioral tool that can be used to assess social motivation in ASD mouse models, and recently worked with colleagues on a protocol for the "social transfer of pain" which enables studies of empathy in mice. With these approaches, I hope we may more thoroughly investigate social behavior, and better identify how animal models of psychiatric disease recapitulate (and fail to recapitulate) the various facets of these complex disorders.
Related publications (all PDFs available for download below):
Rein et al., Nature Protocols, 2020
Rein et al., Genes, Brain and Behavior, 2019
Rein & Jones et al, STAR Protocols, 2022
4. Social Media & Misinformation
Outside of the lab, I share educational science videos on social media. My experiences in these virtual spaces has taught me a lot about human interaction, the way people prefer to learn in modern environments, and how these shape public opinion. I have not only developed a curiosity about how misinformation spreads on the internet, but become emotionally invested in protecting users from misleading or even harmful content. I hope to remain active in this area as the roots of our social lives continue to deepen into our devices, and the line between virtual and in-person interactions inevitably fades.
Related publications (all PDFs available for download below):
Rein, Neuroscience, (in review)
Rein, Cell, 2022
Rein B (2022). Harnessing social media to challenge scientific misinformation. Cell.
SUMMARY: Ben Rein is a postdoctoral scholar at Stanford University and a science communicator on social media. In January, 2022, he and his colleagues wrote an open letter to Spotify to combat scientific misinformation. Here, Rein tells his story, sharing thoughts and lessons learned from publishing the open letter.
Conrow-Graham M, Williams J, Martin J, Zhong P, Cao Q, Rein B, Yan Z (2022). A convergent mechanism of high risk factors ADNP and POGZ in neurodevelopment disorders. Brain.
ABSTRACT: ADNP and POGZ are two top-ranking risk factors for autism spectrum disorder and intellectual disability, but how they are linked to these neurodevelopmental disorders is largely unknown. Both ADNP and POGZ are chromatin regulators, which could profoundly affect gene transcription and cellular function in the brain. Using post-mortem tissue from patients with autism spectrum disorder, we found diminished expression of ADNP and POGZ in the prefrontal cortex, a region highly implicated in neurodevelopmental disorders. To understand the functional role of these neurodevelopmental disorder risk factors, we used viral-based gene transfer to investigate how Adnp or Pogz deficiency in mouse prefrontal cortex affects behavioural, transcriptomic and synaptic function. Mice with prefrontal cortex deficiency of Adnp or Pogz exhibited specific impairment of cognitive task performance. RNA-sequencing revealed that Adnpor Pogz deficiency induced prominent upregulation of overlapping genes enriched in neuroinflammation, similar to the elevation of pro-inflammatory genes in humans with neurodevelopmental disorders. Concomitantly, Adnp or Pogz deficiency led to the significant increase of pro-phagocytic microglial activation in prefrontal cortex, as well as the significant decrease of glutamatergic transmission and postsynaptic protein expression. These findings have uncovered the convergent functions of two top risk factors for autism spectrum disorder and intellectual disability in prefrontal cortex, providing a mechanism linking chromatin, transcriptional and synaptic dysregulation to cognitive deficits associated with neurodevelopmental disorders.
Rapanelli M, Williams J, Ma K, Yang F, Zhong P, Patel R, Kumar M, Qin L, Rein B, Wang ZJ, Kassim B, Javidfar B, Couto L, Akbarian S, Yan Z (2022). Targeting histone demethylase LSD1 for treatment of deficits in autism mouse models. Molecular Psychiatry.
ABSTRACT: Large-scale genetic studies have revealed that the most prominent genes disrupted in autism are chromatin regulators mediating histone methylation/demethylation, suggesting the central role of epigenetic dysfunction in this disorder. Here, we show that histone lysine 4 dimethylation (H3K4me2), a histone mark linked to gene activation, is significantly decreased in the prefrontal cortex (PFC) of autistic human patients and mutant mice with the deficiency of top-ranking autism risk factor Shank3 or Cul3. A brief treatment of the autism models with highly potent and selective inhibitors of the H3K4me2 demethylase LSD1 (KDM1A) leads to the robust rescue of core symptoms of autism, including social deficits and repetitive behaviors. Concomitantly, LSD1 inhibition restores NMDA receptor function in PFC and AMPA receptor-mediated currents in striatum of Shank3-deficient mice. Genome-wide RNAseq and ChIPseq reveal that treatment of Shank3-deficient mice with the LSD1 inhibitor restores the expression and H3K4me2 occupancy of downregulated genes enriched in synaptic signaling and developmental processes. The immediate early gene tightly linked to neuronal plasticity, Egr1, is on the top list of rescued genes. The diminished transcription of Egr1 is recapitulated in PFC of autistic human patients. Overexpression of Egr1 in PFC of Shank3-deficient mice ameliorates social preference deficits. These results have for the first time revealed an important role of H3K4me2 abnormality in ASD pathophysiology, and the therapeutic potential of targeting H3K4me2 demethylase LSD1 or the downstream molecule Egr1 for ASD.
Belin S, Maki BA, Catlin J, Rein B, Popescu GK (2022). Membrane stretch gates NMDA receptors. bioRxiv.
ABSTRACT: N-Methyl-D-aspartic (NMDA) receptors are excitatory glutamate-gated ion channels. Their activation is essential for the normal development, maintenance, and plasticity of excitatory synapses in the central nervous system. They function as glutamate-gated Ca2+-permeable channels, require glycine as co-agonist, and can be modulated by myriad of diffusible ligands and cellular cues, including mechanical stimuli. Previously, we found that in cultured astrocytes, shear stress initiates NMDA receptor-mediated Ca2+ entry in the absence of added agonists, suggesting that in addition to being mechanosensitive, NMDA receptors may be mechanically activated. Here, we used controlled expression of recombinant receptors and non-invasive on-cell single-channel current recordings to show that gentle membrane stretch can substitute for the neurotransmitter glutamate in gating NMDA receptor currents. Notably, stretch-activated currents preserved the hallmark features of the glutamate-gated currents, including glycine-requirement, large unitary conductance, high Ca2+ permeability, and voltage-dependent Mg2+ blockade. Further, we found that the stretch-gated current required the receptor intracellular domain, which may suggest a force-from-filament sensing mechanism. These results are consistent with the hypothesis that mechanical forces can gate NMDA receptor currents even in the absence of synaptic glutamate release, which has important implications for understanding mechanotransduction and the effect of mechanical forces on cells of the central nervous system.
Rein B, Conrow-Graham M, Frazier A, Cao Q, Yan Z (2021). Inhibition of histone deacetylase 5 ameliorates abnormalities in 16p11.2 duplication mouse model. Neuropharmacology.
ABSTRACT: Microduplication of the human 16p11.2 gene locus is associated with a range of neurodevelopmental outcomes, including autism spectrum disorder (ASD). Mice carrying heterozygous 16p11.2 duplication (16p11.2dp/+) display social deficits, which is attributable to impaired GABAergic synaptic function in prefrontal cortex (PFC) driven by downregulation of Npas4, an activity-dependent transcription factor that regulates GABA synapse formation. However, the molecular mechanisms underlying the diminished transcription of Npas4 in 16p11.2 duplication remain unknown. Npas4 is one of the target genes regulated by histone deacetylase 5 (HDAC5), an epigenetic enzyme repressing gene expression via removal of transcription-permissive acetyl groups from histones. Here we report that HDAC5 expression is elevated and histone acetylation is reduced at the Npas4 promoter in PFC of 16p11.2dp/+ mice. Treatment with the HDAC5 inhibitor LMK235 normalizes histone acetylation, restores GABAergic signaling in PFC, and significantly improves social preference in 16p11.2dp/+mice. These findings suggest that HDAC5 inhibition is a promising therapeutic avenue to alleviate genetic, synaptic and behavioral deficits in 16p11.2 duplication conditions.
Catlin J, Marziali LN, Rein B, Yan Z, Feltri ML, Tooley CS (2021). Age-related neurodegeneration and cognitive impairments of NRMT1 knockout mice are preceded by misregulation of RB and expansion of the neural stem cell population. Cell Death & Disease.
ABSTRACT: N-terminal methylation is an important post-translational modification that regulates protein/DNA interactions and plays a role in many cellular processes, including DNA damage repair, mitosis, and transcriptional regulation. Our generation of a constitutive knockout mouse for the N-terminal methyltransferase NRMT1, demonstrated its loss results in severe developmental abnormalities and premature aging. As premature aging is often accompanied by neurodegeneration, we more specifically examined how NRMT1 loss affects neural pathology and cognitive behaviors. Here we find that Nrmt1-/- mice exhibit postnatal enlargement of the lateral ventricles, age-dependent striatal and hippocampal neurodegeneration, memory impairments, and hyperactivity. These morphological and behavior abnormalities are preceded by alterations in neural stem cell (NSC) development. Depletion of quiescent NSC pools in Nrmt1-/- mice is concurrent with expansion of intermediate progenitor and neuroblast pools. These phenotypes are similar to those seen with loss of the NRMT1 target retinoblastoma protein (RB), and we see that NRMT1 loss leads to derepression of RB target genes and abnormal RB phosphorylation and degradation. As also seen with RB loss, neurons in Nrmt1-/- mice fail to exit cell cycle and ultimately undergo NOXA-mediated apoptosis, indicating that early misregulation of RB in Nrmt1-/- mice promotes premature NSC proliferation and contributes to subsequent neurodegenerative phenotypes.
Wang ZJ, Rein B, Zhong P, Williams J, Cao Q, Yang F, Zhang F, Ma K, Yan Z (2021). Autism risk gene KMT5B deficiency in prefrontal cortex induces synaptic dysfunction and social deficits via alterations of DNA repair and gene transcription. Neuropsychopharmacology.
ABSTRACT: Large-scale genetic screenings have identified KMT5B (SUV420H1) - a histone H4K20 di- and tri-methyltransferase that is highly expressed in prefrontal cortex (PFC) - as a top-ranking high-risk gene for autism. However, the biological function of KMT5B in the brain is poorly characterized, and how KMT5B deficiency is linked to autism remains largely unknown. Here we knocked down Kmt5b in PFC and examined behavioral and electrophysiological changes, as well as underlying molecular mechanisms. Mice with Kmt5b deficiency in PFC display social deficits, a core symptom of autism, without the alteration of other behaviors. Kmt5b deficiency also produces deficits in PFC glutamatergic synaptic transmission, which is accompanied by the reduced synaptic expression of glutamate receptor subunits and associated proteins. Kmt5b deficiency-induced reduction of H4K20me2 impairs 53BP1-mediated DNA repair, leading to the elevation of p53 expression and its target gene Ddit4 (Redd1), which is implicated in synaptic impairment. RNA-sequencing data indicate that Kmt5b deficiency results in the upregulation of genes enriched in cellular stress response and ubiquitin-dependent protein degradation. Collectively, this study has revealed the functional role of Kmt5b in the PFC, and suggests that KMT5B deficiency could produce autistic phenotypes by inducing synaptic dysfunction and transcriptional aberration.
Yan Z, Rein B (2021). Mechanisms of synaptic transmission dysregulation in prefrontal cortex: pathophysiological implications. Molecular Psychiatry.
ABSTRACT: The prefrontal cortex (PFC) serves as the chief executive officer of the brain, controlling the highest level cognitive and emotional processes. Its local circuits among glutamatergic principal neurons and GABAergic interneurons, as well as its long-range connections with other brain regions, have been functionally linked to specific behaviors, ranging from working memory to reward seeking. The efficacy of synaptic signaling in the PFC network is profundedly influenced by monoaminergic inputs via the activation of dopamine, adrenergic, or serotonin receptors. Stress hormones and neuropeptides also exert complex effects on the synaptic structure and function of PFC neurons. Dysregulation of PFC synaptic transmission is strongly linked to social deficits, affective disturbance, and memory loss in brain disorders, including autism, schizophrenia, depression, and Alzheimer's disease. Critical neural circuits, biological pathways, and molecular players that go awry in these mental illnesses have been revealed by integrated electrophysiological, optogenetic, biochemical, and transcriptomic studies of PFC. Novel epigenetic mechanism-based strategies are proposed as potential avenues of therapeutic intervention for PFC-involved diseases. This review provides an overview of PFC network organization and synaptic modulation, as well as the mechanisms linking PFC dysfunction to the pathophysiology of neurodevelopmental, neuropsychiatric, and neurodegenerative diseases. Insights from the preclinical studies offer the potential for discovering new medical treatments for human patients with these brain disorders.
Zhang F*, Rein B*, Zhong P, Wang ZJ, Yan Z (2021). Synergistic inhibition of histone modifiers produces therapeutic effects in adult Shank3-deficient mice. Translational Psychiatry. [*Equal contribution]
ABSTRACT: Autism spectrum disorder (ASD) is a lifelong developmental disorder characterized by social deficits and other behavioral abnormalities. Dysregulation of epigenetic processes, such as histone modifications and chromatin remodeling, have been implicated in ASD pathology, and provides a promising therapeutic target for ASD. Haploinsufficiency of the SHANK3 gene is causally linked to ASD, so adult (3-5 months old) Shank3-deficient male mice were used in this drug discovery study. We found that combined administration of the class I histone deacetylase inhibitor Romidepsin and the histone demethylase LSD1 inhibitor GSK-LSD1 persistently ameliorated the autism-like social preference deficits, while each individual drug alone was largely ineffective. Another behavioral abnormality in adult Shank3-deficient male mice, heightened aggression, was also alleviated by administration of the dual drugs. Furthermore, Romidepsin/GSK-LSD1 treatment significantly increased transcriptional levels of NMDA receptor subunits in prefrontal cortex (PFC) of adult Shank3-deficient mice, resulting in elevated synaptic expression of NMDA receptors and the restoration of NMDAR synaptic function in PFC pyramidal neurons. These results have offered a novel pharmacological intervention strategy for ASD beyond early developmental periods.
Rein B, Tan T, Yang F, Wang W, Williams J, Zhang F, Mills A, Yan Z. (2020). Reversal of synaptic and behavioral deficits in a 16p11.2 duplication mouse model via restoration of the GABA synapse regulator Npas4. Molecular Psychiatry.
ABSTRACT: The human 16p11.2 gene locus is a hot spot for copy number variations, which predispose carriers to a range of neuropsychiatric phenotypes. Microduplications of 16p11.2 are associated with autism spectrum disorder (ASD), intellectual disability (ID), and schizophrenia (SZ). Despite the debilitating nature of 16p11.2 duplications, the underlying molecular mechanisms remain poorly understood. Here we performed a comprehensive behavioral characterization of 16p11.2 duplication mice (16p) and identified social and cognitive deficits reminiscent of ASD and ID phenotypes. 16p mice did not exhibit the SZ-related sensorimotor gating deficits, psychostimulant-induced hypersensitivity, or motor impairment. Electrophysiological recordings of 16p mice found deficient GABAergic synaptic transmission and elevated neuronal excitability in the prefrontal cortex (PFC), a brain region critical for social and cognitive functions. RNA-sequencing identified genome-wide transcriptional aberrance in the PFC of 16p mice, including downregulation of the GABA synapse regulator Npas4. Restoring Npas4expression in PFC of 16p mice ameliorated the social and cognitive deficits and reversed GABAergic synaptic impairment and neuronal hyperexcitability. These findings suggest that prefrontal cortical GABAergic synaptic circuitry and Npas4 are strongly implicated in 16p11.2 duplication pathology, and may represent potential targets for therapeutic intervention in ASD.
Rein B, Ma K, Yan Z (2020). A standardized social preference protocol for measuring social deficits in mouse models of autism. Nature Protocols.
ABSTRACT: Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by social communication deficits and other behavioral abnormalities. The three-chamber social preference test is often used to assess social deficits in mouse models of ASD. However, varying and often contradicting phenotypic descriptions of ASD mouse models can be found in the scientific literature, and the substantial variability in the methods used by researchers to assess social deficits in mice could be a contributing factor. Here we describe a standardized three-chamber social preference protocol, which is sensitive and reliable at detecting social preference deficits in several mouse models of ASD. This protocol comprises three phases that can all be completed within 1 d. The test mouse is first habituated to the apparatus containing two empty cups in the side chambers, followed by the pre-test phase in which the mouse can interact with two identical inanimate objects placed in the cups. During the test phase, the mouse is allowed to interact with a social stimulus (an unfamiliar wild-type (WT) mouse) contained in one cup and a novel non-social stimulus contained in the other cup. The protocol is thus designed to assess preference between social and non-social stimuli under conditions of equal salience. The broad implementation of the three-chamber social preference protocol presented here should improve the accuracy and consistency of assessments for social preference deficits associated with ASD and other psychiatric disorders.
Rein B*, Yan Z* (2020). 16p11.2 Copy Number Variations and Neurodevelopmental Disorders. Trends in Neurosciences. (Corresponding author)
ABSTRACT: Copy number variations (CNVs) of the human 16p11.2 genetic locus are associated with a range of neurodevelopmental disorders, including autism spectrum disorder, intellectual disability, and epilepsy. In this review, we delineate genetic information and diverse phenotypes in individuals with 16p11.2 CNVs, and synthesize preclinical findings from transgenic mouse models of 16p11.2 CNVs. Mice with 16p11.2 deletions or duplications recapitulate many core behavioral phenotypes, including social and cognitive deficits, and exhibit altered synaptic function across various brain areas. Mechanisms of transcriptional dysregulation and cortical maldevelopment are reviewed, along with potential therapeutic intervention strategies.
Rein B, Yan Z, Wang ZJ. (2019). Diminished social interaction incentive contributes to social deficits in mouse models of autism spectrum disorder. Genes, Brain and Behavior.
ABSTRACT: One of the core symptoms of autism spectrum disorder (ASD) is impaired social interaction. Currently, no pharmacotherapies exist for this symptom due to complex biological underpinnings and distinct genetic models which fail to represent the broad disease spectrum. One convincing hypothesis explaining social deficits in human ASD patients is amotivation, however it is unknown whether mouse models of ASD represent this condition. Here we used two highly trusted ASD mouse models (male Shank3-deficient mice modeling the monogenic etiology of ASD, and inbred BTBR mice [both male and female] modeling the idiopathic and highly polygenic pathology for ASD) to evaluate the level of motivation to engage in a social interaction. In the behavioral paradigms utilized, a social stimulus was placed in the open arm of the elevated plus maze (EPM), or the light compartment of the light-dark box (LDB). To engage in a social interaction, mice were thus required to endure innately aversive conditions (open areas, height, and/or light). In the modified EPM paradigm, both Shank3 and BTBR mice demonstrated decreased time in the open-arm containing a social stimulus but not a novel object, suggesting reduced incentive to pursue a social interaction in these models. However, these deficits were not expressed under the less severe aversive pressures of the LDB. Collectively, we show that ASD mouse models exhibit diminished social interaction incentive, and provide a new investigation strategy facilitating the study of the neurobiological mechanisms underlying social reward and motivation deficits in neuropsychiatric disorders.
Wang W*, Rein B*, Zhang F, Tan T, Zhong P, Yan Z. (2018). Chemogenetic activation of prefrontal cortex rescues synaptic and behavioral deficits in a mouse model of 16p11.2 deletion syndrome. Journal of Neuroscience. [*Equal contribution]
ABSTRACT: Microdeletion of the human 16p11.2 gene locus has been linked to autism spectrum disorder (ASD) and intellectual disability and confers risk for a number of other neurodevelopmental deficits. Transgenic mice carrying 16p11.2 deletion (16p11+/-) display phenotypes reminiscent of those in human patients with 16p11.2 deletion syndrome, but the molecular mechanisms and treatment strategies for these phenotypes remain unknown. In this study, we have found that both male and female 16p11+/- mice exhibit deficient NMDA receptor (NMDAR) function in the medial prefrontal cortex (mPFC), a brain region critical for high-level "executive" functions. Elevating the activity of mPFC pyramidal neurons with a CaMKII-driven Gq-DREADD (Gq-coupled designer receptors exclusively activated by designer drugs) led to the significant increase of NR2B subunit phosphorylation and the restoration of NMDAR function, as well as the amelioration of cognitive and social impairments in 16p11+/- mice. These results suggest that NMDAR hypofunction in PFC may contribute to the pathophysiology of 16p11.2 deletion syndrome and that restoring PFC activity is sufficient to rescue the behavioral deficits.
Rein BA, McNeil DW, Hayes AR, Hawkins TA, Ng HM, Yura CA. (2018). Evaluation of an avatar-based training program to promote suicide prevention awareness in a college setting. Journal of American College Health.
Objective: Training programs exist that prepare college students, faculty, and staff to identify and support students potentially at risk for suicide. Kognito is an online program that trains users through simulated interactions with virtual humans. This study evaluated Kognito's effectiveness in preparing users to intervene with at-risk students. Participants: Training was completed by 2,727 university students, faculty, and staff from April, 2014 through September, 2015. Methods: Voluntary and mandatory participants at a land-grant university completed Kognito modules designed for higher education, along with pre- and post-assessments. Results: All modules produced significant gains in reported Preparedness, Likelihood, and Self-Efficacy in intervening with troubled students. Despite initial disparities in reported abilities, after training participants reported being similarly capable of assisting at-risk students, including LGBTQ and veteran students. Conclusions: Kognito training appears to be effective, on a large scale, in educating users to act in a facilitative role for at-risk college students.