Open AccessDifferential sensitivity of GABAergic and glycinergic inputs to orexin‐A in preganglionic cardiac vagal neurons of newborn rats 1
Author(s) -
WANG Jijiang,
CHEN Yonghua,
LI Keyong,
SUN Fengyan
Publication year - 2005
Publication title -
acta pharmacologica sinica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.514
H-Index - 90
eISSN - 1745-7254
pISSN - 1671-4083
DOI - 10.1111/j.1745-7254.2005.00231.x
Subject(s) - glycine receptor , gabaergic , orexin , inhibitory postsynaptic potential , neuroscience , postsynaptic current , neuropeptide , orexin a , chemistry , excitatory postsynaptic potential , biology , glycine , medicine , receptor , biochemistry , amino acid
Aim: To test the effect of orexin‐A (hypocretin‐1), a neuropeptide synthesized in the lateral hypothalamus and the perifornical area, on the glycinergic inputs and the GABAergic inputs of cardiac vagal neurons (CVN). Methods: The effects of orexin‐A at three concentrations (20 nmol/L, 100 nmol/L, 500 nmol/L) on the glycinergic inputs and the GABAergic inputs were investigated by using retrograde fluorescent labeling of cardiac neurons (CVN) in the nucleus ambiguus (NA) and the voltage patch‐clamp technique. Results: Orexin‐A dose‐dependently increased the frequency of both the glycinergic and the GABAergic spontaneous inhibitory postsynaptic currents (sIPSC). However, at a lower concentration (20 nmol/L) of orexin‐A, although the frequency of the glycinergic sIPSC was significantly increased, the frequency of the GABAergic sIPSC was not significantly changed. Conclusion: The glycinergic inputs and the GABAergic inputs have different sensitivities to orexin‐A, which suggests that the two kinds of inhibitory inputs might play different roles in the synaptic control of cardiac vagal functions.