Pharmacological characterization of acetylcholine receptors on the dendritic membrane of an identified sensory nonspiking interneuron in crayfish

小龙虾中已鉴定的感觉非尖峰中间神经元树突膜上乙酰胆碱受体的药理学特征

• 批准号: 05640758
• 负责人: TAKAHATA Masakazu
• 金额: $ 1.34万
• 依托单位: Hokkaido University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05640758/
• 关键词: Crayfish; Nonspiking interneuron; Identified cell; Dendrite; Synaptic integration; Acetylcholine; Nicotinic agonist; Muscarinic agonist; 伝達物質; 受容体; 神経生理学

The LDS interneuron, a sensory nonspiking interneuron identified in the terminal abdominal ganglion of the crayfish Procambarus clarkii Girard, is monosynaptically exited by mechanosensory afferents on the side ipsilateral to its soma.Pharmacological characteristics of this synaptic transmission were studied by examining the sffects of acetylcholine (ACh) agonists on the synaptic response evoked by electrical stimulation of sensory afferents using intracellular recording techniques.When ACh or its general agonist carbachol was applied by perfusion, the interneuron showed depolarization and the peak amplitude of the synaptic response was decreased.Current injection experiments confirmed that the decrease in the synaptic response was not due to the depolarization caused by the drug.Similar results were obtained by applying the drug under the low-Ca^<2+>, high Mg^<2+> condition.Both the membrane potential and the synaptic response returned to their original state after washing the prepara … More tion with normal saline.It is thus concluded that the dendritic membrane of the LDS interneuron possesses receptors for ACh.Application of TMA,a selective nicotinic agonist of ACh, also caused the membrane depolarization and a decrease of the synaptic response, whereas application of oxotremorine and other muscarinic agonists caused similar synaptic suppression but never elicited the membrane depolarization.The results suggest that ACh receptors the LDS interneuron resemble the nicotinic ACh receptors in their sensitivity to agonists and that the muscarrinic agonists suppress the synaptic transmission presumably through their presynaptic action.Voltage clamp experiments revealed that the half decay time of the synaptic current evoked by sensory stimulation was about 10msec.This short time course of the synaptic response seems to be based on the rapid action of ACh receptors on the LDS interneuron membrane which would work as the vertebrate nicotinic ACh receptors by opening the ionic channels in direct response to the transmitter molecules. Less

LDS中间神经元是克氏原虾腹部末端神经节中的一种感觉非尖峰中间神经元，由机械感觉神经元在其胞体的同侧单突触发出。用细胞内记录技术检测乙酰胆碱(ACh)激动剂对电刺激感觉传入引起的突触反应的影响，研究了这种突触传递的药理学特征。当ACh或其一般激动剂卡巴胆碱灌流时，目前的注射实验证实，突触反应的降低不是由于药物引起的去极化所致。2+&gt；，高镁；2+&gt；条件。洗涤制备…后，膜电位和突触反应都恢复到原来的状态因此，LDS中间神经元的树突膜上存在ACh受体。应用ACh的选择性烟碱激动剂TMA也可引起膜去极化和突触反应减弱。而应用奥曲莫林和其他M受体激动剂可引起类似的突触抑制，但不会引起膜去极化。结果表明，ACh受体LDS中间神经元对激动剂的敏感性与尼古丁ACh受体相似，而M受体激动剂可能通过其突触前动作抑制突触传递。电压钳实验表明，感觉刺激引起的突触电流的一半衰减时间约为10ms。突触反应的这种短时间过程似乎是基于ACh受体在LDS中间神经元膜上的快速作用，该受体通过直接反应递质分子而开放离子通道来发挥脊椎动物尼古丁受体的作用。较少

项目成果

Hitoshi Aonuma: "Identification of autofluorescent neurons in the crayfish abdominal nervous system" Zoological Science. 10 suppl.114-114 (1993)

Hitoshi Aonuma：“小龙虾腹部神经系统中自发荧光神经元的识别”动物学科学。

Mikio Takahashi: "Membrane properties of motoneuron and premotor nonspiking interneuron dendrites in crayfish" Journal of Neurophysiology. (submitted).

Mikio Takahashi：“小龙虾运动神经元和运动前非尖峰中间神经元树突的膜特性”神经生理学杂志。

高畑雅一: "甲殻類ノンスパイキング介在神経のシナプス統合作用" 比較生理生化学. 12(印刷中). (1995)

Masakazu Takahata：“甲壳类非尖峰中间神经元的突触整合效应”比较生理生物化学 12（出版中）。

Masakazu Takahata: "Outward rectification by the dendritic membrane of an identified nonspiking interneuron in crayfish" Zoological Science. 10 suppl.115-115 (1993)

Masakazu Takahata：“小龙虾中已识别的非尖峰中间神经元的树突膜的向外整流”《动物学科学》。

M.Takahata: "Physiological characteristics of the synantic response of an identified sensory nonspiking interneuron in the crayfish Procambarus clarkii Girard" J.Comp.Physiol.176. in press (1995)

M.Takahata：“克氏原螯虾中已鉴定的感觉非尖峰中间神经元的突触反应的生理特征”J.Comp.Physiol.176。