1
|
Zhang WJ, Shi LL, Zhang L. Dysregulated cortical synaptic plasticity under methyl-CpG binding protein 2 deficiency and its implication in motor impairments. World J Psychiatry 2022; 12:673-682. [PMID: 35663301 PMCID: PMC9150038 DOI: 10.5498/wjp.v12.i5.673] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 07/16/2021] [Accepted: 04/04/2022] [Indexed: 02/06/2023] Open
Abstract
Caused by the mutation of methyl-CpG binding protein 2 (MeCP2), Rett syndrome leads to a battery of severe neural dysfunctions including the regression of motor coordination and motor learning. Current understanding has revealed the motor cortex as the critical region mediating voluntary movement. In this review article, we will summarize major findings from human patients and animal models regarding the cortical synaptic plasticity under the regulation of MeCP2. We will also discuss how mutation of MeCP2 leads to the disruption of cortical circuitry homeostasis to cause motor deficits. Lastly, potential values of physical exercise and neuromodulation approaches to recover neural plasticity and motor function will be evaluated. All of this evidence may help to accelerate timely diagnosis and effective interventions for Rett syndrome patients.
Collapse
Affiliation(s)
- Wei-Jia Zhang
- GHM Institute of CNS Regeneration, Jinan University, Guangzhou 510632, Guangdong Province, China
| | - Ling-Ling Shi
- GHM Institute of CNS Regeneration, Jinan University, Guangzhou 510632, Guangdong Province, China
| | - Li Zhang
- GHM Institute of CNS Regeneration, Jinan University, Guangzhou 510632, Guangdong Province, China
| |
Collapse
|
2
|
Li W. Excitation and Inhibition Imbalance in Rett Syndrome. Front Neurosci 2022; 16:825063. [PMID: 35250460 PMCID: PMC8894599 DOI: 10.3389/fnins.2022.825063] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 01/31/2022] [Indexed: 12/12/2022] Open
Abstract
A loss of the excitation/inhibition (E/I) balance in the neural circuit has emerged as a common neuropathological feature in many neurodevelopmental disorders. Rett syndrome (RTT), a prevalent neurodevelopmental disorder that affects 1:10,000-15,000 women globally, is caused by loss-of-function mutations in the Methyl-CpG-binding Protein-2 (Mecp2) gene. E/I imbalance is recognized as the leading cellular and synaptic hallmark that is fundamental to diverse RTT neurological symptoms, including stereotypic hand movements, impaired motor coordination, breathing irregularities, seizures, and learning/memory dysfunctions. E/I balance in RTT is not homogeneously altered but demonstrates brain region and cell type specificity instead. In this review, I elaborate on the current understanding of the loss of E/I balance in a range of brain areas at molecular and cellular levels. I further describe how the underlying cellular mechanisms contribute to the disturbance of the proper E/I ratio. Last, I discuss current pharmacologic innervations for RTT and their role in modifying the E/I balance.
Collapse
Affiliation(s)
- Wei Li
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States
| |
Collapse
|
3
|
Grieb ZA, Ford EG, Yagan M, Lau BYB, Manfredsson FP, Krishnan K, Lonstein JS. Oxytocin receptors in the midbrain dorsal raphe are essential for postpartum maternal social and affective behaviors. Psychoneuroendocrinology 2021; 131:105332. [PMID: 34182251 PMCID: PMC8405581 DOI: 10.1016/j.psyneuen.2021.105332] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 06/07/2021] [Accepted: 06/15/2021] [Indexed: 01/23/2023]
Abstract
Oxytocin receptors (OTRs) in the midbrain dorsal raphe (DR; the source of most forebrain serotonin) have recently been identified as a potential pharmacological target for treating numerous psychiatric disorders. However, almost all research on this topic has been conducted on males and the role of DR OTRs in female social and affective behaviors is mostly unknown. This may be particularly relevant during early motherhood, which is a time of high endogenous oxytocin signaling, but also a time of elevated risk for psychiatric dysfunction. To investigate whether OTRs in the DR are necessary for postpartum female social and affective behaviors, we constructed and then injected into the DR an adeno-associated virus permanently expressing an shRNA targeting OTR mRNA. We then observed a suite of social and affective behaviors postpartum. OTR knockdown in the maternal DR led to pup loss after parturition, decreased nursing, increased aggression, and increased behavioral despair. These effects of OTR knockdown in the DR may be due to disrupted neuroplasticity in the primary somatosensory cortex (S1), which mediates maternal sensitivity to the tactile cues from young, as we found significantly more plasticity-restricting perineuronal nets (PNNs) in the S1 rostral barrel field and fewer PNNs in the caudal barrel field of OTR-knockdown mothers. These results demonstrate that OTRs in the midbrain DR are essential for postpartum maternal social and affective behaviors, are involved in postpartum cortical plasticity, and suggest that pharmacotherapies targeting OTRs in the DR could be effective treatments for some peripartum affective disorders.
Collapse
Affiliation(s)
- Zachary A Grieb
- Neuroscience Program, Michigan State University, 108 Giltner Hall, East Lansing, MI 48824, USA.
| | - Emma G Ford
- Neuroscience Program, Michigan State University, 108 Giltner Hall, East Lansing, MI 48824, USA
| | - Mahircan Yagan
- Deparment of Biochemistry & Cellular and Molecular Biology, University of Tennessee, 1311 Cumberland Avenue, Knoxville, TN 37996, USA
| | - Billy Y B Lau
- Deparment of Biochemistry & Cellular and Molecular Biology, University of Tennessee, 1311 Cumberland Avenue, Knoxville, TN 37996, USA
| | - Fredric P Manfredsson
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, 400 Monroe Ave NW, Grand Rapids, MI 49503, USA
| | - Keerthi Krishnan
- Deparment of Biochemistry & Cellular and Molecular Biology, University of Tennessee, 1311 Cumberland Avenue, Knoxville, TN 37996, USA
| | - Joseph S Lonstein
- Neuroscience Program, Michigan State University, 108 Giltner Hall, East Lansing, MI 48824, USA
| |
Collapse
|
4
|
Guadagno A, Belliveau C, Mechawar N, Walker CD. Effects of Early Life Stress on the Developing Basolateral Amygdala-Prefrontal Cortex Circuit: The Emerging Role of Local Inhibition and Perineuronal Nets. Front Hum Neurosci 2021; 15:669120. [PMID: 34512291 PMCID: PMC8426628 DOI: 10.3389/fnhum.2021.669120] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 07/29/2021] [Indexed: 01/10/2023] Open
Abstract
The links between early life stress (ELS) and the emergence of psychopathology such as increased anxiety and depression are now well established, although the specific neurobiological and developmental mechanisms that translate ELS into poor health outcomes are still unclear. The consequences of ELS are complex because they depend on the form and severity of early stress, duration, and age of exposure as well as co-occurrence with other forms of physical or psychological trauma. The long term effects of ELS on the corticolimbic circuit underlying emotional and social behavior are particularly salient because ELS occurs during critical developmental periods in the establishment of this circuit, its local balance of inhibition:excitation and its connections with other neuronal pathways. Using examples drawn from the human and rodent literature, we review some of the consequences of ELS on the development of the corticolimbic circuit and how it might impact fear regulation in a sex- and hemispheric-dependent manner in both humans and rodents. We explore the effects of ELS on local inhibitory neurons and the formation of perineuronal nets (PNNs) that terminate critical periods of plasticity and promote the formation of stable local networks. Overall, the bulk of ELS studies report transient and/or long lasting alterations in both glutamatergic circuits and local inhibitory interneurons (INs) and their associated PNNs. Since the activity of INs plays a key role in the maturation of cortical regions and the formation of local field potentials, alterations in these INs triggered by ELS might critically participate in the development of psychiatric disorders in adulthood, including impaired fear extinction and anxiety behavior.
Collapse
Affiliation(s)
- Angela Guadagno
- Douglas Mental Health University Institute, Montreal, QC, Canada
- Department of Psychiatry, McGill University, Montreal, QC, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
| | - Claudia Belliveau
- Douglas Mental Health University Institute, Montreal, QC, Canada
- Department of Psychiatry, McGill University, Montreal, QC, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
| | - Naguib Mechawar
- Douglas Mental Health University Institute, Montreal, QC, Canada
- Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Claire-Dominique Walker
- Douglas Mental Health University Institute, Montreal, QC, Canada
- Department of Psychiatry, McGill University, Montreal, QC, Canada
| |
Collapse
|
5
|
Horrell ND, Acosta MC, Saltzman W. Plasticity of the paternal brain: Effects of fatherhood on neural structure and function. Dev Psychobiol 2021; 63:1499-1520. [PMID: 33480062 PMCID: PMC8295408 DOI: 10.1002/dev.22097] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 12/14/2020] [Accepted: 12/23/2020] [Indexed: 12/12/2022]
Abstract
Care of infants is a hallmark of mammals. Whereas parental care by mothers is obligatory for offspring survival in virtually all mammals, fathers provide care for their offspring in only an estimated 5%-10% of genera. In these species, the transition into fatherhood is often accompanied by pronounced changes in males' behavioral responses to young, including a reduction in aggression toward infants and an increase in nurturant behavior. The onset of fatherhood can also be associated with sensory, affective, and cognitive changes. The neuroplasticity that mediates these changes is not well understood; however, fatherhood can alter the production and survival of new neurons; function and structure of existing neurons; morphology of brain structures; and neuroendocrine signaling systems. Although these changes are thought to promote infant care by fathers, very little evidence exists to support this hypothesis; in most cases, neither the mechanisms underlying neuroplasticity in fathers nor its functional significance is known. In this paper, we review the available data on the neuroplasticity that occurs during the transition into fatherhood. We highlight gaps in our knowledge and future directions that will provide key insights into how and why fatherhood alters the structure and functioning of the male brain.
Collapse
Affiliation(s)
| | - Melina C. Acosta
- Graduate Program in Neuroscience and Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA USA
| | - Wendy Saltzman
- Graduate Program in Neuroscience and Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA USA
| |
Collapse
|
6
|
Stevenson P, Casenhiser DM, Lau BY, Krishnan K. Systematic analysis of goal-related movement sequences during maternal behaviour in a female mouse model for Rett syndrome. Eur J Neurosci 2021; 54:4528-4549. [PMID: 34043854 PMCID: PMC8450021 DOI: 10.1111/ejn.15327] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 05/17/2021] [Accepted: 05/23/2021] [Indexed: 11/28/2022]
Abstract
Rodent dams seek and gather scattered pups back to the nest (pup retrieval), an essential aspect of maternal care. Systematic analysis of the dynamic sequences of goal-related movements that comprise the entire behavioural sequence, which would be ultimately essential for understanding the underlying neurobiology, is not well-characterized. Here, we present such analysis across 3 days in alloparental female mice (Surrogates or Sur) of two genotypes; Mecp2Heterozygotes (Het), a female mouse model for Rett syndrome and their wild type (WT) siblings. We analysed CBA/CaJ and C57BL/6J WT surrogates for within-strain comparisons. Frame-by-frame analysis over different phases was performed manually using DataVyu software. We previously showed that surrogate Het are inefficient at pup retrieval, by end-point analysis such as latency index and errors. Here, the sequence of searching, pup-approach and successful retrieval streamlines over days for WT, while Het exhibits variations in this pattern. Goal-related movements between Het and WT are similar in other phases, suggesting context-driven atypical patterns in Het during the pup retrieval phase. We identified proximal pup approach and pup grooming as atypical tactile interactions between pups and Het. Day-by-day analysis showed dynamic changes in goal-related movements in individual animals across genotypes and strains. Overall, our approach (1) highlights natural variation in individual mice on different days, (2) establishes a "gold-standard" manually curated dataset to help build behavioural repertoires using machine learning approaches, and (3) suggests atypical tactile sensory processing and possible regression in a female mouse model for Rett syndrome.
Collapse
Affiliation(s)
- Parker Stevenson
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996
| | - Devin M. Casenhiser
- Audiology and Speech Pathology Department, University of Tennessee Health Sciences Center, Knoxville, TN 37996
| | - Billy Y.B. Lau
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996
| | - Keerthi Krishnan
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996
| |
Collapse
|
7
|
Negwer M, Piera K, Hesen R, Lütje L, Aarts L, Schubert D, Nadif Kasri N. EHMT1 regulates Parvalbumin-positive interneuron development and GABAergic input in sensory cortical areas. Brain Struct Funct 2020; 225:2701-2716. [PMID: 32975655 PMCID: PMC7674571 DOI: 10.1007/s00429-020-02149-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 09/10/2020] [Indexed: 02/08/2023]
Abstract
Mutations in the Euchromatic Histone Methyltransferase 1 (EHMT1) gene cause Kleefstra syndrome, a rare form of intellectual disability (ID) with strong autistic traits and sensory processing deficits. Proper development of inhibitory interneurons is crucial for sensory function. Here we report a timeline of Parvalbumin-positive (PV+) interneuron development in the three most important sensory cortical areas in the Ehmt1+/- mouse. We find a hitherto unreported delay of PV+ neuron maturation early in sensory development, with layer- and region-specific variability later in development. The delayed PV+ maturation is also reflected in a delayed maturation of GABAergic transmission in Ehmt1+/- auditory cortex, where we find a reduced GABA release probability specifically in putative PV+ synapses. Together with earlier reports of excitatory impairments in Ehmt1+/- neurons, we propose a shift in excitatory-inhibitory balance towards overexcitability in Ehmt1+/- sensory cortices as a consequence of early deficits in inhibitory maturation.
Collapse
Affiliation(s)
- Moritz Negwer
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB, Nijmegen, The Netherlands
| | - Karol Piera
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB, Nijmegen, The Netherlands
| | - Rick Hesen
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB, Nijmegen, The Netherlands
| | - Lukas Lütje
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB, Nijmegen, The Netherlands
| | - Lynn Aarts
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB, Nijmegen, The Netherlands
| | - Dirk Schubert
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, 6500 HB, Nijmegen, The Netherlands
| | - Nael Nadif Kasri
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB, Nijmegen, The Netherlands.
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, 6500 HB, Nijmegen, The Netherlands.
| |
Collapse
|