ABSTRACT
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.
ABSTRACT
Pain is an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage. The processing of pain involves complicated modulation at the levels of the periphery, spinal cord, and brain. The pathogenesis of chronic pain is still not fully understood, which makes the clinical treatment challenging. Optogenetics, which combines optical and genetic technologies, can precisely intervene in the activity of specific groups of neurons and elements of the related circuits. Taking advantage of optogenetics, researchers have achieved a body of new findings that shed light on the cellular and circuit mechanisms of pain transmission, pain modulation, and chronic pain both in the periphery and the central nervous system. In this review, we summarize recent findings in pain research using optogenetic approaches and discuss their significance in understanding the pathogenesis of chronic pain.
Subject(s)
Humans , Brain , Chronic Pain , Neurons , Optogenetics , Spinal CordABSTRACT
To explore the mechanism of rapid eye movement (REM) sleep regulation and the drugs that affect it. This article summarizes the relevant nucleuses regulating REM sleep in the pontine, medulla, and hypothalamus starting from the neural circuit that regulates REM sleep. Drugs that affect REM sleep, such as selective norepinephrine reuptake inhibitors and selective 5-hydroxytryptamine (5-HT) reuptake inhibitors, etc. The mechanism of action can be summarized as reducing the degradation of norepinephrine and 5-HT of synaptic sites, prolonging the action time of neurotransmitters, reducing the reuptake of presynaptic membrane, prolonging the action time of transmitters in the synaptic space, and relatively increasing norepinephrine and 5-HT neurons excitement.