Effects Of Progesterone On Excitability Of Dorsal Nucleus Neurons In The Vagus Nerve Of Rat

Progesterone(P)has a certain effect on neurological protection and nerve regeneration in the central nervous system,in addition to play a reproductive role.Our lab has proven progesterone receptors(PR)express in the neurons of Nodose Ganglion、Dorsal root Ganglion and Duodenum.It is assumed that P may play a regulatory role by influencing the nerve reflex pathway.It has been shown that PR is widely expressed in the brain of rats,and PR was medium level expression in the dorsal motor nucleus of the vagus(DMV).DMV is a parasympathetic motor neuron that controls the activities of the visceral organs such as the gastrointestinal tract.It is unclear P can have a certain effect on DMV neuronal activity and the mechanism? In this study,In this study,whole-cell patch-clamp technique was used to study the effect of different concentrations of P(10、102、103 and 104 nM)on the excitability of PTX-induced DMV neurons and its mechanism,aiming to demonstrate at the critical of the visceral reflex pathway whether P can affect the excitability of the neurons to regulate the visceral function.Achieve the following main results:1、The data of 104 neurons in this experiment was detected,the rate of neurons sent to stomach and gut were 29.8% and 35.6%,respectively.AND its electronical characteristic were exploused multifarious peculiarity with P applying.2、PTX could significantly increase the excitability of neurons sent to stomach and gut,and the number of actoin potential had significant difference among them(F(1,166)= 4.40,P< 0.05)。The synergistic effect would affect neither the membrane permeability nor the formation of actoin potential and the characteristic of critical ion channel.3、The excitability of DMV neurons sent to stomach and gut was significantly inhibited with effect of concentrations of progesterone.4、Various concentrations of progesterone had a concentration dependent inhibiting effect of DMV neuronal excitability induced by PTX,and there have discrepancy of this inhibiting effect due to the difference of DMV neurons sent to stomach and gut.The above results confirmed that the progesterone could regulate the excitability of neurons sent to stomach and gut by GABA pathways,indicated that the electrophy biological mechanism of regulation of visceral function induced by progesterone through influencing DMV neuronal excitability in rats,supported that P could regulate the DMV neuronal excitability with a novel regulation approach different from dircet pathway mediated by hormone receptor and classical pathway induced by hypothalamic-pituitary-gonadal axis in rats’ DMV which are the important node of the internal neuromodulation pathway,enriched the content of neuroendocrine immune network theory and provided the theoretical reference of progesterone using in clinic and production.