Effects of neuroactive peptide urocortin on STN neuron's spontaneousdischarge and relationship with CRF-2R / 中国药理学通报

ABSTRACT

Aim To investigate the effects of endocrinal petptide urocortin on subthalamic nucleus (STN) neuron''s discharge, also observe the convergence effect of UCN with dopamine (DA) and glutamate (GLU), so as to understand the regulation effects of UCN and its mechanism in Parkinson''s disease (PD).Methods Forty Sprague-Dawley rats were used in this experiment.Nerve electrophysiology method-microiontophoresis was used to observe the effects of UCN on STN neuron firing rates and firing wave.Astressin (AST, the blocker of CRF receptor 2), protein kinase A (PKA) were used to observe the effects of UCN whether via CRF-2R and PKA signal pathway.Moreover, given UCN during the period of DA and GLU, the effects of UCN on DA and GLU in STN neurons were determined.Results During the period of using the UCN, UCN could inhibit the firing rate of 82％ (27/33) STN neuron (P<0.01), and the firing discharge rates were reduced from(3.65±0.27)Hz to (2.05±0.33) Hz (P<0.01).However, the inhibitory effects of UCN in STN could be antagonized by AST.Given UCN during the period of microiontophoresis of inhibitory neurotransmitter (DA) and excited neurotransmitter (GLU), UCN could enhance the effects of DA and attenuate the excitatory effects of GLU (P<0.01).Conclusion UCN and GLU/DA in STN, UCN play inhibitory and regulated effects on STN neurotransmitters(DA and GLU)via CRF-2 receptor and PKA signal pathway.