Activity of Preganglionic Neurons in Vitro

体外节前神经元的活性

• 批准号: 7342644
• 负责人: Nae J Dun
• 金额: $ 27.09万
• 依托单位: TEMPLE UNIV OF THE COMMONWEALTH
• 依托单位国家: 美国
• 财政年份: 1983
• 资助国家: 美国
• 起止时间: 1983-04-01 至 2010-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7342644
• 关键词: 4-Aminopyridine; Abbreviations; Acute; Address; Adrenergic Agents; Adult; Affect; Amphetamines; Antibodies; Area; Arrhythmia; Biological; Biological Assay; Blood Circulation; Blood Pressure; CARTPT gene; Cardiovascular Abnormalities; Cardiovascular Diseases; Cell Nucleus; Cells; Chemical Stimulation; Chemicals; Choline O-Acetyltransferase; Chromosome Pairing; Chronic; Clinical; Closure; Cocaine; Cocaine Users; Complement component C1s; Corpus striatum structure; Dose; Epidemiologic Studies; Excitatory Postsynaptic Potentials; Fiber; Frequencies; Glass; Glutamates; Goals; Heart Rate; Immune Sera; Immunohistochemistry; In Situ; In Vitro; Infarction; Injection of therapeutic agent; Intrathecal Injections; Ischemia; Laboratories; Location; Membrane; Messenger RNA; Minor; Neurons; Neurotransmitters; Numbers; Oryctolagus cuniculus; Peptides; Peripheral; Pertussis Toxin; Phenylethanolamine N-Methyltransferase; Phosphate Buffer; Physiologic pulse; Physiological; Play; Process; Pulse taking; Rattus; Reverse Transcriptase Polymerase Chain Reaction; Risk; Role; Route; Saline; Serum; Signal Transduction Pathway; Site; Slice; Spinal Cord; Spinal Cord Column; Stroke; Sympathetic Nervous System; Synapses; Synaptic Transmission; Tea; Techniques; Tetraethylammonium; Tetrodotoxin; Therapeutic Agents; Transcriptional Activation; Tyrosine 3-Monooxygenase; Up-Regulation; Urethane; Vascular Diseases; Week; adrenergic; day; design; dorsal motor nucleus; immunoreactivity; in vivo; middle age; novel therapeutics; pituitary adenylate cyclase activating polypeptide; postsynaptic; presynaptic; receptor; research study; response

DESCRIPTION (provided by applicant): Epidemiological studies indicate a higher risk of myocardiac infarction, arrhythmia, stroke and ischemia in young and middle-aged adults who are "occasional" or "regular" cocaine users. Cocaine- and amphetamine-regulated transcript (CART) peptide is a recently identified peptide, the mRNA of which is up-regulated in certain central neurons following acute administration of cocaine or amphetamine. Subsequent studies including those from our laboratory show that CART peptide is expressed in a wide variety of central and peripheral neurons including the sympathetic preganglionic neurons (SPNs), which in turn receive CART-immunoreactive fibers possibly arising from neurons in the medullary C1 area. The central hypothesis is that CART peptide is excitatory to SPNs and that it is up-regulated by cocaine, resulting in an exaggerated sympathetic response in cocaine users. The goal of this project is to characterize in the rat the biological action of CART at the synapse of SPNs, with particular reference to circulation. First, immunohistochemical and tract-tracing studies will determine the location of CART neurons in the medulla or supramedullary nuclei that project to the SPNs. Second, microprobes coated with CART antiserum will be inserted into the intermediolateral cell column (IML) to assay the release of CART-immunoreactive substances from isolated spinal cords in situ or anesthetized rats in vivo. Third, RT-PCR will be used to establish whether or not CART mRNA is up-regulated in the medulla/spinal cord after acute and chronic injection of cocaine (10-20 mg/kg). Fourth, whole-cell patch recordings will be made from single SPNs in the transverse spinal cord slice and the effects of CART peptide on the electrical activity and synaptic transmission of these neurons will be studied. The mechanism and signal transduction pathways underlying the CART action will be investigated. Lastly, the physiological role of CART peptide, which will be administered by intrathecal route on blood pressure and heart rate will be assessed in urethane-anesthetized rats. A number of studies suggest that the sympathetic nervous system plays a major role in cocaine-induced cardiovascular abnormality. To be able to identify the neurotransmitter(s) and the circuitry that respond to cocaine would be a major step toward a better understanding of the intrinsic mechanisms that underlie cocaine-induced vascular disorders. More importantly, identification of putative transmitters involved in these processes would permit a rational approach to the design of novel therapeutics agents for the management of cocaine-induced cardiovascular disorder.

描述（由申请人提供）：流行病学研究表明，在“偶尔”或“常规”可卡因使用者的年轻和中年成年人中，心肌梗塞，心律不齐，中风和缺血的风险更高。可卡因和苯丙胺调节的转录物（CART）肽是最近鉴定出的肽，在急性施用可卡因或苯丙胺后，其mRNA在某些中央神经元中被上调。随后的研究（包括我们实验室的研究）表明，CART肽在各种中央和周围神经元中表达，包括交感神经前神经元（SPNS），这些神经元（SPNS）又接收可能是由髓质C1区域神经元引起的CART免疫反应纤维。中心假设是，CART肽是SPNS的兴奋性，并且由可卡因上调，从而导致可卡因使用者的交感反应夸张。该项目的目的是表征大鼠在SPNS突触中的CART的生物学作用，特别是指循环。首先，免疫组织化学和道追踪研究将确定推进到SPNS的髓质或胸膜上核的位置。其次，将涂有卡车抗血清的微探测将插入中间外侧细胞柱（IML）中，以测定从分离的脊髓原位或体内麻醉大鼠中释放CART免疫反应物质。第三，RT-PCR将用于确定急性和慢性注射可卡因（10-20 mg/kg）后的髓质/脊髓中的CART mRNA是否被上调。第四，全细胞斑块记录将由横向脊髓切片中的单个SPN制成，并且将研究CART肽对这些神经元的电活动和突触传递的影响。将研究CART作用的基础机理和信号转导途径。最后，将通过鞘内的血压和心率来评估CART肽的生理作用，该肽将在氨基甲酸酯麻醉大鼠中评估。许多研究表明，交感神经系统在可卡因诱导的心血管异常中起主要作用。能够鉴定神经递质和对可卡因反应的电路将是对可卡因引起的血管疾病基于的内在机制的更好理解的主要一步。更重要的是，对这些过程中涉及的推定发射器的识别将允许采用合理的方法来设计可卡因诱导的心血管疾病的新型治疗剂。