1051
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Bozdagi O, Sakurai T, Papapetrou D, Wang X, Dickstein DL, Takahashi N, Kajiwara Y, Yang M, Katz AM, Scattoni ML, Harris MJ, Saxena R, Silverman JL, Crawley JN, Zhou Q, Hof PR, Buxbaum JD. Haploinsufficiency of the autism-associated Shank3 gene leads to deficits in synaptic function, social interaction, and social communication. Mol Autism 2010; 1:15. [PMID: 21167025 PMCID: PMC3019144 DOI: 10.1186/2040-2392-1-15] [Citation(s) in RCA: 416] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Accepted: 12/17/2010] [Indexed: 02/07/2023] Open
Abstract
Background SHANK3 is a protein in the core of the postsynaptic density (PSD) and has a critical role in recruiting many key functional elements to the PSD and to the synapse, including components of α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionic acid (AMPA), metabotropic glutamate (mGlu) and N-methyl-D-aspartic acid (NMDA) glutamate receptors, as well as cytoskeletal elements. Loss of a functional copy of the SHANK3 gene leads to the neurobehavioral manifestations of 22q13 deletion syndrome and/or to autism spectrum disorders. The goal of this study was to examine the effects of haploinsufficiency of full-length Shank3 in mice, focusing on synaptic development, transmission and plasticity, as well as on social behaviors, as a model for understanding SHANK3 haploinsufficiency in humans. Methods We used mice with a targeted disruption of Shank3 in which exons coding for the ankyrin repeat domain were deleted and expression of full-length Shank3 was disrupted. We studied synaptic transmission and plasticity by multiple methods, including patch-clamp whole cell recording, two-photon time-lapse imaging and extracellular recordings of field excitatory postsynaptic potentials. We also studied the density of GluR1-immunoreactive puncta in the CA1 stratum radiatum and carried out assessments of social behaviors. Results In Shank3 heterozygous mice, there was reduced amplitude of miniature excitatory postsynaptic currents from hippocampal CA1 pyramidal neurons and the input-output (I/O) relationship at Schaffer collateral-CA1 synapses in acute hippocampal slices was significantly depressed; both of these findings indicate a reduction in basal neurotransmission. Studies with specific inhibitors demonstrated that the decrease in basal transmission reflected reduced AMPA receptor-mediated transmission. This was further supported by the observation of reduced numbers of GluR1-immunoreactive puncta in the stratum radiatum. Long-term potentiation (LTP), induced either with θ-burst pairing (TBP) or high-frequency stimulation, was impaired in Shank3 heterozygous mice, with no significant change in long-term depression (LTD). In concordance with the LTP results, persistent expansion of spines was observed in control mice after TBP-induced LTP; however, only transient spine expansion was observed in Shank3 heterozygous mice. Male Shank3 heterozygotes displayed less social sniffing and emitted fewer ultrasonic vocalizations during interactions with estrus female mice, as compared to wild-type littermate controls. Conclusions We documented specific deficits in synaptic function and plasticity, along with reduced reciprocal social interactions in Shank3 heterozygous mice. Our results are consistent with altered synaptic development and function in Shank3 haploinsufficiency, highlighting the importance of Shank3 in synaptic function and supporting a link between deficits in synapse function and neurodevelopmental disorders. The reduced glutamatergic transmission that we observed in the Shank3 heterozygous mice represents an interesting therapeutic target in Shank3-haploinsufficiency syndromes.
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Affiliation(s)
- Ozlem Bozdagi
- Seaver Autism Center for Research and Treatment, Mount Sinai School of Medicine, New York, NY 10029, USA.,Department of Psychiatry, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Takeshi Sakurai
- Seaver Autism Center for Research and Treatment, Mount Sinai School of Medicine, New York, NY 10029, USA.,Department of Psychiatry, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Danae Papapetrou
- Department of Neuroscience, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Xiaobin Wang
- Department of Neurology, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Dara L Dickstein
- Department of Neuroscience, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Nagahide Takahashi
- Department of Psychiatry, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Yuji Kajiwara
- Department of Psychiatry, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Mu Yang
- Laboratory of Behavioral Neuroscience, National Institute of Mental Health, Bethesda, MD 20892-3730, USA
| | - Adam M Katz
- Laboratory of Behavioral Neuroscience, National Institute of Mental Health, Bethesda, MD 20892-3730, USA
| | - Maria Luisa Scattoni
- Laboratory of Behavioral Neuroscience, National Institute of Mental Health, Bethesda, MD 20892-3730, USA.,Istituto Superiore di Sanità, Rome, Italy
| | - Mark J Harris
- Laboratory of Behavioral Neuroscience, National Institute of Mental Health, Bethesda, MD 20892-3730, USA
| | - Roheeni Saxena
- Laboratory of Behavioral Neuroscience, National Institute of Mental Health, Bethesda, MD 20892-3730, USA
| | - Jill L Silverman
- Laboratory of Behavioral Neuroscience, National Institute of Mental Health, Bethesda, MD 20892-3730, USA
| | - Jacqueline N Crawley
- Laboratory of Behavioral Neuroscience, National Institute of Mental Health, Bethesda, MD 20892-3730, USA
| | - Qiang Zhou
- Department of Neurology, Mount Sinai School of Medicine, New York, NY 10029, USA.,Genentech, South San Francisco, CA 94080, USA
| | - Patrick R Hof
- Department of Neuroscience, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Joseph D Buxbaum
- Seaver Autism Center for Research and Treatment, Mount Sinai School of Medicine, New York, NY 10029, USA.,Department of Psychiatry, Mount Sinai School of Medicine, New York, NY 10029, USA.,Department of Neuroscience, Mount Sinai School of Medicine, New York, NY 10029, USA.,Department of Genetics and Genomic Sciences, Mount Sinai School of Medicine, New York, NY 10029, USA
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1052
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Abstract
Many mental disorders and neurodegenerative and neurodevelopmental diseases involve cognitive deficits. Remarkable advances and new technologies are providing a clearer picture of the molecular basis of cognition. In conjunction with an SFN2010 symposium, we provided here a brief overview of the molecular mechanisms of cognition, with emphasis on the development of treatments for cognitive disorders. Activity-dependent changes in gene expression and protein synthesis integrate with synapse selection to form memory circuits. A neuronal activity-dependent molecular tagging system that uses the gene expression program to record memory circuit formation represents one new tool to study cognition. Regulation of protein translation, protein degradation, cytoskeletal dynamics, extracellular matrix interactions, second messenger signaling, and neurotransmitter receptor trafficking and function are all components of synaptic remodeling essential for cognition. Selective targeting of specific effectors in these processes, such as NMDA receptors, may serve as an effective strategy to treat cognitive deficits.
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1053
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Multiple autism-like behaviors in a novel transgenic mouse model. Behav Brain Res 2010; 218:29-41. [PMID: 21093492 DOI: 10.1016/j.bbr.2010.11.026] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 11/05/2010] [Accepted: 11/09/2010] [Indexed: 11/21/2022]
Abstract
Autism spectrum disorder (ASD) diagnoses are behaviorally based with no defined universal biomarkers, occur at a 1:110 ratio in the population, and predominantly affect males compared to females at approximately a 4:1 ratio. One approach to investigate and identify causes of ASD is to use organisms that display abnormal behavioral responses that model ASD-related impairments. This study describes a novel transgenic mouse, MALTT, which was generated using a forward genetics approach. It was determined that the transgene integrated within a non-coding region on the X chromosome. The MALTT line exhibited a complete repertoire of ASD-like behavioral deficits in all three domains required for an ASD diagnosis: reciprocal social interaction, communication, and repetitive or inflexible behaviors. Specifically, MALTT male mice showed deficits in social interaction and interest, abnormalities in pup and juvenile ultrasonic vocalization communications, and exhibited a repetitive stereotypy. Abnormalities were also observed in the domain of sensory function, a secondary phenotype prevalently associated with ASD. Mapping and expression studies suggested that the Fam46 gene family may be linked to the observed ASD-related behaviors. The MALTT line provides a unique genetic model for examining the underlying biological mechanisms involved in ASD-related behaviors.
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1054
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Pearson BL, Pobbe RLH, Defensor EB, Oasay L, Bolivar VJ, Blanchard DC, Blanchard RJ. Motor and cognitive stereotypies in the BTBR T+tf/J mouse model of autism. GENES BRAIN AND BEHAVIOR 2010; 10:228-35. [PMID: 21040460 DOI: 10.1111/j.1601-183x.2010.00659.x] [Citation(s) in RCA: 131] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The BTBR T+tf/J inbred mouse strain displays a variety of persistent phenotypic alterations similar to those exhibited in autism spectrum disorders (ASDs). The unique genetic background of the BTBR strain is thought to underlie its lack of reciprocal social interactions, elevated repetitive self-directed grooming, and restricted exploratory behaviors. In order to clarify the existence, range, and mechanisms of abnormal repetitive behaviors within BTBR mice, we performed detailed analyses of the microstructure of self-grooming patterns and noted increased overall grooming, higher percentages of interruptions in grooming bouts and a concomitant decrease in the proportion of incorrect sequence transitions compared to C57BL/6J inbred mice. Analyses of active phase home-cage behavior also revealed an increase in stereotypic bar-biting behavior in the BTBR strain relative to B6 mice. Finally, in a novel object investigation task, the BTBR mice exhibited greater baseline preference for specific unfamiliar objects as well as more patterned sequences of sequential investigations of those items. These results suggest that the repetitive, stereotyped behavior patterns of BTBR mice are relatively pervasive and reflect both motor and cognitive mechanisms. Furthermore, other pre-clinical mouse models of ASDs may benefit from these more detailed analyses of stereotypic behavior.
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Affiliation(s)
- B L Pearson
- Department of Psychology, and Békésy Laboratory of Neurobiology, Pacific Biosciences Research Center, University of Hawaii at Manoa, 1993 East-West Road, Honolulu, HI 96822, USA.
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1055
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Yang M, Perry K, Weber MD, Katz AM, Crawley JN. Social peers rescue autism-relevant sociability deficits in adolescent mice. Autism Res 2010; 4:17-27. [PMID: 20928844 DOI: 10.1002/aur.163] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Accepted: 08/13/2010] [Indexed: 01/14/2023]
Abstract
Behavioral therapies are currently the most effective interventions for treating the diagnostic symptoms of autism. We employed a mouse model of autism to evaluate components of behavioral interventions that improve sociability in mice. BTBR T+tf/J (BTBR) is an inbred mouse strain that exhibits prominent behavioral phenotypes with face validity to all three diagnostic symptom categories of autism, including robust and well-replicated deficits in social approach and reciprocal social interactions. To investigate the role of peer interactions in the development of sociability, BTBR juvenile mice were reared in the same home cage with juvenile mice of a highly social inbred strain, C57BL/6J (B6). Subject mice were tested as young adults for sociability and repetitive behaviors. B6 controls reared with B6 showed their strain-typical high sociability. BTBR controls reared with BTBR showed their strain-typical lack of sociability. In contrast, BTBR reared with B6 as juveniles showed significant sociability as young adults. A 20-day intervention was as effective as a 40-day intervention for improving social approach behavior. High levels of repetitive self-grooming in BTBR were not rescued by peer-rearing with B6, indicating specificity of the intervention to the social domain. These results from a robust mouse model of autism support the interpretation that social enrichment with juvenile peers is a beneficial intervention for improving adult outcome in the social domain. This novel paradigm may prove useful for discovering factors that are essential for effective behavioral treatments, and biological mechanisms underlying effective behavioral interventions.
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Affiliation(s)
- Mu Yang
- Laboratory of Behavioral Neuroscience, Intramural Research Program, National Institute of Mental Health, NIH, Bethesda, Maryland 20892-3730, USA.
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1057
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Sociability and motor functions in Shank1 mutant mice. Brain Res 2010; 1380:120-37. [PMID: 20868654 DOI: 10.1016/j.brainres.2010.09.026] [Citation(s) in RCA: 168] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 09/03/2010] [Accepted: 09/03/2010] [Indexed: 02/07/2023]
Abstract
Autism is a neurodevelopmental disorder characterized by aberrant reciprocal social interactions, impaired communication, and repetitive behaviors. While the etiology remains unclear, strong evidence exists for a genetic component, and several synaptic genes have been implicated. SHANK genes encode a family of synaptic scaffolding proteins located postsynaptically on excitatory synapses. Mutations in SHANK genes have been detected in several autistic individuals. To understand the consequences of SHANK mutations relevant to the diagnostic and associated symptoms of autism, comprehensive behavioral phenotyping on a line of Shank1 mutant mice was conducted on multiple measures of social interactions, social olfaction, repetitive behaviors, anxiety-related behaviors, motor functions, and a series of control measures for physical abilities. Results from our comprehensive behavioral phenotyping battery indicated that adult Shank1 null mutant mice were similar to their wildtype and heterozygous littermates on standardized measures of general health, neurological reflexes and sensory skills. Motor functions were reduced in the null mutants on open field activity, rotarod, and wire hang, replicating and extending previous findings (Hung et al., 2008). A partial anxiety-like phenotype was detected in the null mutants in some components of the light ↔ dark task, as previously reported (Hung et al., 2008) but not in the elevated plus-maze. Juvenile reciprocal social interactions did not differ across genotypes. Interpretation of adult social approach was confounded by a lack of normal sociability in wildtype and heterozygous littermates. All genotypes were able to discriminate social odors on an olfactory habituation/dishabituation task. All genotypes displayed relatively high levels of repetitive self-grooming. Our findings support the interpretation that Shank1 null mice do not demonstrate autism-relevant social interaction deficits, but confirm and extend a role for Shank1 in motor functions.
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1058
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General and social anxiety in the BTBR T+ tf/J mouse strain. Behav Brain Res 2010; 216:446-51. [PMID: 20816701 DOI: 10.1016/j.bbr.2010.08.039] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 08/19/2010] [Accepted: 08/25/2010] [Indexed: 12/13/2022]
Abstract
BTBR T+ tf/J (BTBR) is an inbred mouse strain that shows behavioral traits with analogies to the three diagnostic symptoms of autism spectrum disorder (ASD); deficits in social interaction, impaired communication, and repetitive behaviors with restricted interests. Previous findings reveal that when compared to C57BL/6J (B6) and other inbred strains, BTBR exhibit normal to low anxiety-like traits in paradigms designed to assess anxiety-related behaviors. The current study assessed the generality of these anxiety findings. In experiment 1, B6 and BTBR mice were tested in the elevated plus maze (EPM), mouse defense test battery (MDTB) and elevated zero-maze. BTBR mice exhibited an anxiogenic profile in the EPM, with a reduction in open arm time and an increase in risk assessment behaviors, as compared to B6. In the MDTB, BTBR showed enhanced vocalization to the predator, and significantly less locomotor activity than B6 in the pre-threat situation, but significantly more locomotion than B6 following exposure to a predator threat, suggesting enhanced defensiveness to the predator. In the zero-maze, BTBR mice showed a significantly higher number of entries and time spent in the open segments of the apparatus, when compared to B6. In experiment 2, a three-chambered social preference test was used to evaluate effects of the systemic administration of an anxiolytic compound, diazepam, on B6 and BTBR social approach. Diazepam consistently increased time in the compartment containing the social stimulus, for both B6 and BTBR mice. However, in the vehicle treated groups, B6 mice spent significantly more time while BTBR mice spent significantly less time in the social stimulus compartment; after diazepam administration both B6 and BTBR strains significantly preferred the social stimulus chamber. These results suggest that while the anxiety responses of BTBR mice to novel situations (EPM and zero-maze) are inconsistent, BTBR mice appear to be more defensive to animate threat stimuli (predator or another mouse). Reduction of anxiety by diazepam normalized the social preference of BTBR for a mouse stimulus in the three-chambered test.
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