Fig. 2 | Nature Communications

Fig. 2

From: Preventing acute asthmatic symptoms by targeting a neuronal mechanism involving carotid body lysophosphatidic acid receptors

Fig. 2

LPA stimulation of the carotid body increases efferent vagal activity. a The dual perfused in situ preparation used to record phrenic and vagal activity in response to specific carotid body stimulation. b Phrenic (upper trace) and vagal (lower trace) activity with the carotid body intact under brainstem hypocapnia (black trace) causing cessation of phrenic firing (neural apnea) and vagal quiescence. Activity is restored following carotid body stimulation with 5 µM LPA (blue arrow/trace), with restoration of vagal activity. c In denervated preparations the stimulatory effect of LPA on vagal and phrenic activity is absent. d Expanded sections of traces from b indicated by the red boxes, illustrating phrenic and vagal activity prior to brainstem hypocapnia induced apnea, apnea and following LPA injections. e, f Summary data during hypocapnia in intact (solid) and carotid body (CB) denervated (crossed) preparations for phrenic frequency (Phrenic burst min−1; Mann Whitney: U = 0, p = 0.002, ** median ± range) and vagal total activity (normalized to baseline normoxic activity, normalized units, independent t test: t10 = 4.008, p = 0.0025, ** mean ± sem)