Novel Approach for Simultaneous Recording of Renal Sympathetic Nerve Activity and Blood Pressure with Intravenous Infusion in Conscious, Unrestrained Mice.
February 14th, 2018
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Anesthetized mice exhibit non-physiological systemic blood pressure, which precludes meaningful assessment of autonomic tone given the intimate relationship between blood pressure and the autonomic nervous system. Thus, a novel method to simultaneously record renal sympathetic nerve activity and blood pressure with intravenous infusion in conscious mice is outlined.
Overview
This article outlines a novel method for assessing renal sympathetic nerve activity in conscious mice, avoiding the confounding effects of anesthesia. This technique allows for reliable evaluation of autonomic tone in a more physiologically relevant setting.
Key Study Components
Area of Science
- Neuroscience
- Physiology
- Experimental Biology
Background
- Anesthetized mice show non-physiological blood pressure.
- Blood pressure is closely linked to autonomic nervous system activity.
- Conscious models provide more accurate assessments of nerve activity.
- Recent interest in mouse models necessitates improved methodologies.
Purpose of Study
- To evaluate renal sympathetic activity in conscious mice.
- To eliminate the confounding effects of anesthesia.
- To provide a reliable technique for assessing autonomic tone.
Methods Used
- Surgical preparation of the mouse.
- Positioning the mouse for surgery.
- Making incisions for nerve activity assessment.
- Simultaneous recording of nerve activity and blood pressure.
Main Results
- Successful assessment of renal sympathetic nerve activity in conscious mice.
- Demonstrated reliability of the technique without anesthesia.
- Provided insights into autonomic tone in a resting state.
Conclusions
- This method allows for accurate evaluation of autonomic function.
- Conscious models enhance the understanding of renal sympathetic activity.
- The technique is accessible for researchers interested in autonomic studies.
Frequently Asked Questions
What is the significance of studying renal sympathetic nerve activity?
Understanding renal sympathetic nerve activity is crucial for assessing autonomic regulation and its impact on blood pressure.
How does anesthesia affect the assessment of autonomic tone?
Anesthesia can alter blood pressure and nerve activity, leading to inaccurate assessments of autonomic tone.
What advantages does this method offer over traditional techniques?
This method allows for assessments in conscious mice, providing more physiologically relevant data without the effects of anesthesia.
Is this technique applicable to other animal models?
While this study focuses on mice, the principles may be adapted for other conscious animal models.
What preparations are needed before the surgical procedure?
Mice must be properly anesthetized for surgery, and the surgical area should be cleaned and sterilized.
Can this method be used to study other aspects of the autonomic nervous system?
Yes, the technique can potentially be adapted to study various autonomic functions beyond renal sympathetic activity.
Executive Industry Relevance
Simultaneous recording of renal sympathetic nerve activity (RSNA) and blood pressure in conscious, unrestrained mice addresses a critical gap in translational cardiovascular and metabolic research. This method eliminates anesthesia-induced confounders, enabling more predictive assessment of autonomic regulation relevant to hypertension, chronic kidney disease, and metabolic disorders. The approach enhances mechanistic de-risking and target validation at early discovery and preclinical inflection points.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Enables direct interrogation of autonomic pathways implicated in disease models.
- Supports functional target validation by linking RSNA modulation to physiological blood pressure changes.
- Improves predictive confidence for candidate targets affecting sympathetic tone.
- Facilitates mechanistic de-risking by isolating neural contributions to cardiovascular phenotypes.
Screening & Assay Development
- Provides a validated, reproducible system for quantitative RSNA and hemodynamic readouts.
- Enables standardized assessment of pharmacological agents on autonomic and cardiovascular endpoints.
- Supports assay development for compounds modulating sympathetic activity in vivo.
- Delivers robust, physiologically relevant data for compound triage and prioritization.
Translational & Preclinical Research
- Aligns preclinical models with human disease-relevant autonomic and cardiovascular mechanisms.
- Enables continuity from early discovery through preclinical validation of autonomic targets.
- Supports translational biomarker development by correlating RSNA with blood pressure responses.
- Reduces translational risk by modeling interventions in conscious, unrestrained animals.
Pipeline & Workflow Integration
This method integrates into the discovery-to-preclinical continuum, supporting hypothesis testing, lead identification, and translational validation for autonomic and cardiovascular targets.
- Discovery Biology: Facilitates mechanistic studies of sympathetic regulation and disease progression.
- Screening: Provides quantitative, reproducible RSNA and blood pressure endpoints for compound evaluation.
- Analytics: Enables statistical comparison of intervention effects on neural and hemodynamic outputs.
- Translational Research: Bridges preclinical findings to clinical hypotheses in hypertension and metabolic disease.
- Enterprise Reuse: Establishes a reusable platform for autonomic and cardiovascular research across therapeutic areas.
Operational & Enterprise Impact
- Scientific Value: Increases predictive confidence and reduces mechanistic ambiguity in autonomic target validation.
- Operational Value: Standardizes in vivo autonomic measurements, improving reproducibility and scalability.
- Strategic Value: Informs go/no-go decisions and enhances capital efficiency by reducing late-stage biological risk.
- Portfolio Impact: Enables risk-adjusted prioritization of autonomic and cardiovascular programs.
Implementation Considerations
- Requires expertise in microsurgery and neurophysiological recording in small animals.
- Demands specialized instrumentation for chronic telemetric and electrophysiological monitoring.
- Necessitates rigorous cross-team standardization of surgical and analytical protocols.
- Adaptation to other model systems may require protocol optimization and validation.
- Signal stability and animal welfare must be closely monitored to ensure data integrity.
Biopharma FAQs
Why does null hypothesis testing matter for RSNA target validation?
Null hypothesis testing in RSNA experiments enables objective assessment of whether interventions produce statistically significant changes in nerve activity or blood pressure, supporting robust target validation and reducing false positives in early discovery.
How does independent variable isolation fit the RSNA recording workflow?
Isolating variables such as pharmacological agents or physiological stimuli during RSNA and blood pressure recording allows clear attribution of observed effects to specific interventions, strengthening mechanistic insights and pipeline decision-making.
What do quantitative RSNA and blood pressure measurements enable?
Quantitative measurements provide reproducible endpoints for comparing intervention effects, facilitating dose-response analysis, and supporting cross-study and cross-compound evaluation in cardiovascular and metabolic research portfolios.
Why are replication requirements critical for cross-functional RSNA studies?
Replication ensures that RSNA and blood pressure findings are robust and generalizable, enabling reliable data sharing across discovery, pharmacology, and translational teams and supporting enterprise-wide confidence in mechanistic conclusions.
What statistical analysis capabilities are required before RSNA implementation?
Teams must be equipped to perform statistical comparisons of RSNA and hemodynamic data, including baseline normalization, intervention effect quantification, and validation of signal specificity, to ensure actionable and reproducible results.
Chapters in this video
0:04
Title
0:44
Surgical Implantation of the RSNA Electrode
3:58
Implantation of Blood Pressure Radiotelemeter
6:02
Implantation and Exteriorization of the Jugular Venous Catheter
7:45
Sample Experimental Protocol and Validation of RSNA Signal
8:40
Results: Renal Sympathetic Nerve Activity (RSNA) in Conscious Mice
10:10
Conclusion
