Experimental teaching is an important component of the course Medical Immunology,which requires the use of experimental animals and the execution of experimental animals by medical students.By applying the carbon dioxide euthanasia system,it can effectively reduce the pain of experimental animals,ensure their welfare,and meet ethical requirements.It can also improve the efficiency of experimental teaching in Medical Immunology,reduce environmental pollution,and promote medical students to estab-lish scientific values and worldviews that pay attention to experimental animals and respect life,which is conducive to becoming future medical service talents.In the experimental teaching of Medical Immunology,the appropriate application of carbon dioxide euthanasia system combined with effective ideological and political construction of the curriculum can further implement the Party's educational policy of cultivating morality and talents,and lay a good foundation for cultivating medical talents with comprehensive knowledge,high skills and excellent quality.

Experimental teaching is an important component of the course Medical Immunology,which requires the use of experimental animals and the execution of experimental animals by medical students.By applying the carbon dioxide euthanasia system,it can effectively reduce the pain of experimental animals,ensure their welfare,and meet ethical requirements.It can also improve the efficiency of experimental teaching in Medical Immunology,reduce environmental pollution,and promote medical students to estab-lish scientific values and worldviews that pay attention to experimental animals and respect life,which is conducive to becoming future medical service talents.In the experimental teaching of Medical Immunology,the appropriate application of carbon dioxide euthanasia system combined with effective ideological and political construction of the curriculum can further implement the Party's educational policy of cultivating morality and talents,and lay a good foundation for cultivating medical talents with comprehensive knowledge,high skills and excellent quality.

The nucleus tractus solitarii (NTS) is one of the morphologically and functionally defined centers that engage in the autonomic regulation of cardiovascular activity. Phenotypically-characterized NTS neurons have been implicated in the differential regulation of blood pressure (BP). Here, we investigated whether phenylethanolamine N-methyltransferase (PNMT)-expressing NTS (NTS^PNMT) neurons contribute to the control of BP. We demonstrate that photostimulation of NTS^PNMT neurons has variable effects on BP. A depressor response was produced during optogenetic stimulation of NTS^PNMT neurons projecting to the paraventricular nucleus of the hypothalamus, lateral parabrachial nucleus, and caudal ventrolateral medulla. Conversely, photostimulation of NTS^PNMT neurons projecting to the rostral ventrolateral medulla produced a robust pressor response and bradycardia. In addition, genetic ablation of both NTS^PNMT neurons and those projecting to the rostral ventrolateral medulla impaired the arterial baroreflex. Overall, we revealed the neuronal phenotype- and circuit-specific mechanisms underlying the contribution of NTS^PNMT neurons to the regulation of BP.
Solitary Nucleus/metabolism* ; Blood Pressure/physiology* ; Phenylethanolamine N-Methyltransferase/metabolism* ; Neurons/metabolism* ; Paraventricular Hypothalamic Nucleus/metabolism*

Leptin, an adipocyte-derived peptide hormone, has been shown to facilitate breathing. However, the central sites and circuit mechanisms underlying the respiratory effects of leptin remain incompletely understood. The present study aimed to address whether neurons expressing leptin receptor b (LepRb) in the nucleus tractus solitarii (NTS) contribute to respiratory control. Both chemogenetic and optogenetic stimulation of LepRb-expressing NTS (NTS^LepRb) neurons notably activated breathing. Moreover, stimulation of NTS^LepRb neurons projecting to the lateral parabrachial nucleus (LPBN) not only remarkably increased basal ventilation to a level similar to that of the stimulation of all NTS^LepRb neurons, but also activated LPBN neurons projecting to the preBötzinger complex (preBötC). By contrast, ablation of NTS^LepRb neurons projecting to the LPBN notably eliminated the enhanced respiratory effect induced by NTS^LepRb neuron stimulation. In brainstem slices, bath application of leptin rapidly depolarized the membrane potential, increased the spontaneous firing rate, and accelerated the Ca²⁺ transients in most NTS^LepRb neurons. Therefore, leptin potentiates breathing in the NTS most likely via an NTS-LPBN-preBötC circuit.
Leptin/pharmacology* ; Membrane Potentials ; Neurons/metabolism* ; Solitary Nucleus/metabolism*