Calcium transient of CA1 pyramidal neurons induced by potassium blocker 4-aminopyridine in acute hippocampal slices
10.3760/cma.j.issn.1671-8925.2011.05.010
- VernacularTitle:钾通道阻断剂4-氨基吡啶诱导海马CA1锥体神经元钙瞬变
- Author:
Tao SU
1
;
Wen-Dong CONG
;
Wei-Ping LIAO
Author Information
1. 广州医学院附属第二医院
- Keywords:
Potassium channel;
Calcium transient;
4-aminopyridine;
Pyramidal neuron
- From:
Chinese Journal of Neuromedicine
2011;10(5):467-470
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the calcium transient of CA1 pyramidal neurons induced by potassium blocker 4-aminopyridine (4-AP) in acute hippocampal slices to explore the relation between potassium channel function and calcium transient, and their mechanism. Methods Fluorescent probe was employed to mark the hippocampai neurons in acute brain slices of rats; confocal microscopy was used to perform calcium imaging to observe the influences of different concentrations of 4-AP and perfusate with/without calcium on calcium transient of CA1 pyramidal neurons. Results The response of [Ca2+]I to lower concentration of 4-AP (<15 mmol/L) was in a dose-dependent manner (r2=0.910, P=0.000); the higher the concentration of 4-AP (20-80 mmol/L), the lower the peak level of calcium transient. The latency and amplitude of calcium transient induced by 4-AP were obviously reduced when the extracellular condition was switched to an absence of calcium, which was significantly different as compared with that with calcium (P<0.05). Conclusion Blockade of potassium channels with 4-AP can increase [Ca2+]I in the hippocampal pyramidal neurons of acute slices. The increase of [Ca2+]1 to 4-AP could be ascribe to calcium release from intracellular stores and calcium influx from extracellular matrix.
