RESUMEN
Objective:To conduct a glucagon like peptide-1(GLP-1)controllability model rat by chemical genetics, and observe the impact of GLP-1 neuron excitability on appetite.Methods:Fifteen rats were evenly divided into Green fluorescent protein(GFP)group, HM3D group, and HM4D group. Various combinations of adeno-associated virus(rAAV)were injected into the nucleus tractus solitarius(NTS). rAAV-GLP-1-cre and rAAV-GFP-dio were administered in rats of GFP group. The rats of HM3D group were injected with rAAV-GLP-1-cre and rAAV-HM3D-mCherry-dio while rAAV-GLP-1-cre and rAAV-HM4D-mCherry-dio were injected in rats of HM4D group . The optimal dose of clozapine N-oxide(CNO)was selected based on feeding behavior and body weight changes of rats after intraperitoneal injection of different doses of CNO. The controllability of GLP-1 neurons was confirmed by comparing with intraperitoneal injection of saline. The number of activated GLP-1 neurons in the NTS area and the expression of POMC neurons in the hypothalamus were detected 30 minutes after CNO injection.Results:GLP-1 neurons in the NTS area of rats were successfully labeled. The rat of HM3D group revealed a decrease in food intake( P=0.021)while the rat of HM4D group showed an increase( P=0.002), when given 1 mg/kg of CNO, no changes at the dose of 0.5 mg/kg and 3.0 mg/kg. Immunofluorescence showed that the activity of GLP-1 neurons in NTS of GFP group was lower than that of HM3D group( P=0.022), and higher compared with that of the HM4D group( P=0.049). The expression of GLP-1 neurons in NTS and POMC neurons in the hypothalamus of the HM3D group after intraperitoneal injection of CNO was also higher than that in the HM4D group( P=0.003). Conclusion:Using chemical genetics technology, GLP-1 controllability model rat could be successfully established via injecting varying combinations of rAAV into the NTS area of rat. Injection of 1 mg/kg CNO can effectively activate or inhibit the neuron to regulate appetite.
RESUMEN
Objective:To investigate the effect of electroacupuncture (EA) on synaptic plasticity and the expression of autophagy-related proteins in the hippocampus in Alzheimer′s disease (AD). To explore how EA might improve cognition in AD.Methods:Healthy male Sprague-Dawley rats were randomly divided into a sham operation group, a model group and an EA group. The rat model of AD was established by injecting Aβ1-42 into the bilateral CA1 area of the hippocampus. The sham operation group was injected with an equal amount of normal saline at the same site. Starting the day after the successful modelling, the EA group received 20 minutes of EA treatment at the Baihui (DU20) and bilateral Shenshu (BL23) acupoints once a day, 6 times a week for 2 weeks. The rats′ learning and memory were then tested using a Morris water maze. The long-term potentiation (LEP) in the hippocampus was assessed using a MED64 microelectrode array and any ultrastructural changes of autophagosomes were detected using an electron microscope. The expression of the autophagy-related proteins Beclin-1 and microtubule associated protein light chain 3 (LC3) in the hippocampus were determined using western blotting.Results:The escape latency was significantly shorter and the times crossing the platform increased significantly in the EA group compared with the model group. The average amplitude of the postsynaptic excitatory field potentials in the EA group was significantly higher than among the model group. There were many autophagosomes in the hippocampal neurons of the model group, significantly more than in the EA group. The LC3II/LC3I ratio and Beclin-1 protein expression decreased significantly in the EA group compared to the model group.Conclusions:EA can improve learning and memory and restore LEP in the hippocampus of rats modeling AD. The mechanism may be related to its regulation of autophagy in hippocampal neurons.