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Deslauriers JC, Ghotkar RP, Russ LA, Jarman JA, Martin RM, Tippett RG, Sumathipala SH, Burton DF, Cole DC, Marsden KC. Cyfip2 controls the acoustic startle threshold through FMRP, actin polymerization, and GABA B receptor function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.22.573054. [PMID: 38187577 PMCID: PMC10769380 DOI: 10.1101/2023.12.22.573054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Animals process a constant stream of sensory input, and to survive they must detect and respond to dangerous stimuli while ignoring innocuous or irrelevant ones. Behavioral responses are elicited when certain properties of a stimulus such as its intensity or size reach a critical value, and such behavioral thresholds can be a simple and effective mechanism to filter sensory information. For example, the acoustic startle response is a conserved and stereotyped defensive behavior induced by sudden loud sounds, but dysregulation of the threshold to initiate this behavior can result in startle hypersensitivity that is associated with sensory processing disorders including schizophrenia and autism. Through a previous forward genetic screen for regulators of the startle threshold a nonsense mutation in Cytoplasmic Fragile X Messenger Ribonucleoprotein (FMRP)-interacting protein 2 (cyfip2) was found that causes startle hypersensitivity in zebrafish larvae, but the molecular mechanisms by which Cyfip2 establishes the acoustic startle threshold are unknown. Here we used conditional transgenic rescue and CRISPR/Cas9 to determine that Cyfip2 acts though both Rac1 and FMRP pathways, but not the closely related FXR1 or FXR2, to establish the acoustic startle threshold during early neurodevelopment. To identify proteins and pathways that may be downstream effectors of Rac1 and FMRP, we performed a candidate-based drug screen that indicated that Cyfip2 can also act acutely to maintain the startle threshold branched actin polymerization and N-methyl D-aspartate receptors (NMDARs). To complement this approach, we used unbiased discovery proteomics to determine that loss of Cyfip2 alters cytoskeletal and extracellular matrix components while also disrupting oxidative phosphorylation and GABA receptor signaling. Finally, we functionally validated our proteomics findings by showing that activating GABAB receptors, which like NMDARs are also FMRP targets, restores normal startle sensitivity in cyfip2 mutants. Together, these data reveal multiple mechanisms by which Cyfip2 regulates excitatory/inhibitory balance in the startle circuit to control the processing of acoustic information.
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Affiliation(s)
- Jacob C. Deslauriers
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA
| | - Rohit P. Ghotkar
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA
- Current address: Putnam Associates, Boston, Massachusetts, USA
| | - Lindsey A. Russ
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA
- Current address: Department of Pharmacology & Physiology, Georgetown University, Washington D.C., USA
| | - Jordan A. Jarman
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA
- Current address: Department of Physiology and Biophysics, Boston University, Boston, MA, USA
| | - Rubia M. Martin
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA
- Current address: U.S. Environmental Protection Agency, Raleigh-Durham-Chapel Hill, North Carolina, USA
| | - Rachel G. Tippett
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA
| | - Sureni H. Sumathipala
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA
| | - Derek F. Burton
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA
| | - D. Chris Cole
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA
| | - Kurt C. Marsden
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA
- Center for Human Health and the Environment (CHHE), North Carolina State University, Raleigh, North Carolina, USA
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Panda SR, Panja P, Soni U, Naidu VGM. Neurobehavioral Analysis to Assess Olfactory and Motor Dysfunction in Parkinson's Disease. Methods Mol Biol 2024; 2761:511-528. [PMID: 38427259 DOI: 10.1007/978-1-0716-3662-6_35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative condition, primarily affecting dopaminergic neurons. It is defined by motor impairments, such as bradykinesia, stiffness, resting tremor, and postural instability. The striatum, a structure essential for motor control, is impaired in function due to the significant loss of dopaminergic neurons in the substantia nigra and the development of Lewy bodies in the surviving nigral dopaminergic neurons. Olfactory impairment is one of the earliest indications of neurodegenerative disorders like PD that appear years before motor symptoms and cognitive decline development. Olfactory dysfunction is the most common nonmotor PD sign in at least 90% of cases, frequently occurring 5-10 years before motor disturbances. Surprisingly, even though olfactory impairment is intimately linked to PD and is thought to be a potential biomarker, little is known about the brain process underlying this failure. Exposure to environmental toxins has been linked to olfactory dysfunction, leading to nigral neurodegeneration and loss of motor functions. Behavioral neuroscience plays a significant role in identifying and characterizing these olfactory and motor symptoms. In preclinical research, novel treatment approaches are being evaluated in rodent models by behavioral phenotyping to ensure their efficacy. This chapter describes neurobehavioral analysis to assess olfactory and motor dysfunction in rodent models of Parkinson's disease.
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Affiliation(s)
- Samir Ranjan Panda
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Guwahati, Assam, India
| | - Pallabi Panja
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Guwahati, Assam, India
| | - Ujjawal Soni
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Guwahati, Assam, India
| | - V G M Naidu
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Guwahati, Assam, India.
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