Issue Archive

Properties of whole-cell potassium currents in mechanically dissociated Drosophila larval central neurons

Xu Taixiang, Lu Hui, Wang Qiang, Wu Longjun, Liu Jin, Zhou Zhuan, Xu Tianle

Department of Neurobiology & Biophysics, School of Life Sciences,University of Science and Technology of China.Hefei 230027,Anhui；China；Neuroscence Institute of Shanghai, Chinese Academy of Sciences.Shanghai 200031

Abstract

Using patch clamp technique, the whole-cell K~(+) currents in type II neurons were characterized by containing a transient 4-AP-sensitive current (I_(A)) and a more slowly inactivating, TEA-sensitive component (I_(K)). According to their kinetic properties, five types of whole-cell K~(+) currents were identified. Type A current exhibited primarily fast transient K~(+) currents that activated and inactivated rapidly. The majority of the neurons, however, slowly inactivated K~(+) currents with variable inactivation time course (type B current). Type C current, being present in a small number of the cells, was mainly composed of noninactivating components. Some of the neurons expressed both transient and slow inactivating components, but the slowly inactivating components could reach more than 50% of the peak current (type D current). Type E current showed distinct voltage-dependent activation properties, characterized by its "bell-shaped" activation curve. Type E current was inhibited by application of Ca~(2+)-free solution or 0.1 mmol/L Cd~(2+). Moreover, this novel current ran down much more rapidly than other types. These results indicate that different K~(+) channels, which have different kinetic and pharmacological properties, underlie the whole-cell K~(+) currents in type II neurons of Drosophila larval central nervous system.

Key words: Drosophila;Mechanical dissociation;Type II neuron;K~(+)current

Received: 　　Accepted:

Corresponding author: 　　E-mail:

Citing This Article：

Xu Taixiang, Lu Hui, Wang Qiang, Wu Longjun, Liu Jin, Zhou Zhuan, Xu Tianle. Properties of whole-cell potassium currents in mechanically dissociated Drosophila larval central neurons. Acta Physiol Sin 2002; 54 (5): (in Chinese with English abstract).