Detection of baroreceptor activity in rat vagal nerve recording using a multi-channel cuff-electrode and real-time coherent averaging

Abstract

Electrical stimulation of afferent nerve fibers originating from pressure sensors can trigger the baroreflex to reduce blood pressure and might be an alternative to treat patients with hypertension. In this study, baroreceptor compound activity was detected using multi-channel cuff-electrode recordings on rat vagal nerve. In order to isolate the vagal nerve signals from external potentials (such as ECG- and EMG-coupling), a tripolar measuring technique was applied. To eliminate noise and neural signals corresponding to other organs, coherent averaging was used. The baroreceptor-correlated signals appear predominantly in one of the electrode channels, presumably close to the corresponding neural substrate. This localization was done in real-time.

An Intraneural Electrode for Bioelectronic Medicines for Treatment of Hypertension

“…Consequently, given the similarity between the cuff recordings and the intraneural recordings, the present intraneural‐derived BPnPs and RnPs could serve as markers for the BP and respiration, respectively. Consistent with our results, Plachta et al have recorded BP‐related signals from the LVN of rats using a polyimide cuff electrode . However, in contrast with our results, those BP‐related signals did not resemble the BP waves and the mentioned authors did not report whether or not those signals reflected in any way BP changes .…”

“…Indeed, a recent study with cuff VNS for heart failure in humans showed inefficient recruitment of the targeted VN fibers , which indicates that selective activation of the human ABR fibers is improbable with such electrodes. Moreover, as the recording capabilities of the above‐mentioned selective cuff electrodes were tested in rats exclusively and only to locate the ABR fibers relative to the electrode contacts , it is unclear if such electrodes could be used to record ABR signals qualitatively suitable for the extraction of BP markers from a larger sized LVN.…”

Effect of Cardiac-Cycle-Synchronized Selective Vagal Stimulation on Heart Rate and Blood Pressure in Rats

“…The tripole contacts located near the baroreceptor fibers (ADN) were identified through coherent averaging [16]. These contacts were chosen for the stimulation procedure described below.…”

Influence of Clonidine on Antihypertensive Selective Afferent Vagal Nerve Stimulation in Rats

“…The surgeries and experiments occurred in a commonly grounded Faraday cage. The tripole contacts located near the baroreceptive fibers (ADN) were identified via coherent averaging, as previously described, by visual identification . Identification of ADN‐fibers is based on the assumption that the baroreceptive information has, due to its origin in pressure‐sensitive sensors in the aortic arch, a pulse‐synchronized, pulsatile character and can therefore be identified against the stochastically distributed background noise and activity.…”