Calcium-sensing Receptor Signaling and Epilepsy

钙敏感受体信号传导与癫痫

• 批准号: 9280838
• 负责人: Stephen M Smith
• 金额: --
• 依托单位: PORTLAND VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9280838
• 关键词: Action Potentials; Address; Affect; Agonist; Alcohol withdrawal syndrome; Anticonvulsants; Antiepileptic Agents; Automobile Driving; Blood - brain barrier anatomy; Brain; Brain Neoplasms; Calcium; Calcium-Sensing Receptors; Cations; Cells; Chronic; Chronic Disease; Collaborations; Communication; DNA Sequence Alteration; Data; Disease; Drug Targeting; Elderly; Electroporation; Epilepsy; Evoked Potentials; Excitatory Synapse; FDA approved; Failure; G-Protein-Coupled Receptors; GTP-Binding Protein alpha Subunits, Gs; Glutamates; Heterogeneity; Hippocampus (Brain); Imaging Techniques; Impact Seizures; Inherited; Inhibitory Synapse; Interneurons; Ion Channel; Lead; Light; Link; Mediating; Medicine; Modeling; Molecular; Mus; Mutation; Nerve; Neurons; Patch-Clamp Techniques; Pathway interactions; Patients; Pharmaceutical Preparations; Physiological; Pilocarpine; Play; Positioning Attribute; Predisposition; Prevalence; Probability; Property; Public Health; Reagent; Receptor Activation; Receptor Signaling; Regulation; Resistance; Risk; Role; Seizures; Shapes; Signal Pathway; Signal Transduction; Stroke; Synapses; Synaptic Transmission; Testing; Trauma; Traumatic Brain Injury; Veterans; War; Work; biophysical analysis; biophysical properties; cinacalcet; design; experience; experimental study; extracellular; gamma-Aminobutyric Acid; in vivo; knock-down; live cell imaging; mouse model; mutant; neocortical; neuronal cell body; neuronal excitability; neurotransmission; neurotransmitter release; new therapeutic target; novel; patch clamp; public health relevance; receptor; receptor function; response; small hairpin RNA; transmission process; tumor; voltage

DESCRIPTION (provided by applicant): The extracellular calcium-sensing receptor (CaSR) is widely distributed in the brain, is modulated by changes in the external calcium concentration ([Ca2+]o), and impacts neuronal activity in a number of ways. In addition to inhibiting a non-selective cation channel in nerve terminals, inhibiting action potential evoked transmitter release, and stimulating spontaneous neurotransmission, all of which may change the predisposition for seizures to occur, it has also been proposed that CaSR transduces calcium-mediated changes in neuronal excitability. The questions to be addressed are, what are the detailed mechanisms by which CaSR signaling change result in changes of neuronal activity and does CaSR activation impact seizures? In addition as part of this proposal we will determine: 1) if CaSR activation impacts spontaneous and evoked transmission equally, 2) if CaSR signaling is the pathway that mediates [Ca2+]o-dependent changes in neuronal excitability, and 3) which of these changes is likely to mediate an antiepileptic action of CaSR agonists? The hypothesis is that CaSR, a G-protein coupled receptor (GPCR), is an important target for novel antiepileptic drugs. The proposed project is designed to test this hypothesis and determine the mechanism by which the CaSR mutations affect CaSR signaling and neuronal activity using the following four-part approach. First, it will be determined how wild-type and mutant CaSR affect the excitability of neocortical neurons in response to changes in [Ca2+]o. These experiments will employ biophysical measurements from single neurons that are expressing wt CaSR. Second we will use direct recordings from nerve terminals to determine if CaSR signaling at the terminal and soma use the same mechanisms. Third we will determine how CaSR signaling impacts neuron-neuron communication. Here experiments will allow comparison of the effects of CaSR signaling on evoked and spontaneous transmission at inhibitory and excitatory synapses. Fourth we will evaluate if CaSR agonists reduce seizures in two mouse models. Successful completion of this proposal will substantially impact the field by increasing our understanding of calcium regulation in the brain and expanding our understanding of how CaSR signaling might be utilized to treat epilepsy and other forms of seizures.

描述（由申请人提供）：