Key Points
- To characterize the temporal processing of evoked arterial baroreceptor afferent activity in monosynaptic and polysynaptic neurons within the nucleus of the solitary tract.
- Conducted extracellular single-cell recordings in the nucleus of the solitary tract across 26 pentobarbital-anesthetized male Sprague-Dawley rats.
- Delivered electrical stimulation to the aortic depressor nerve using a conditioning-test paradigm to assess evoked potentials and time-dependent inhibition across 49 identified neurons.
- Monosynaptic neurons (n=22) exhibited significantly shorter average onset latencies (17 ± 2 ms vs. 26 ± 1 ms, P < 0.05) and lower latency variability (4 ± 1 ms vs. 8 ± 1 ms, P < 0.05) than polysynaptic neurons.
- At a 50-ms conditioning-test interval, test responses averaged 79 ± 8% of control in monosynaptic neurons versus 32 ± 8% in polysynaptic neurons, with polysynaptic inhibition persisting up to 200 ms.
- Only 5 of 22 monosynaptic neurons displayed >50% inhibition at 50 ms, which correlated with significantly lower mean arterial pressure during testing.
Structured PICO
PPopulation26 pentobarbital-sodium-anesthetized male Sprague-Dawley rats (49 neurons examined)
IInterventionElectrical stimulation of the aortic nerve using a conditioning-test paradigm
OOutcomeTemporal processing of evoked activity in NTS neurons (onset latency and time-dependent inhibition)surrogate
NTS neurons receiving monosynaptic input from the aortic depressor nerve infrequently exhibit time-dependent inhibition, potentially allowing unmodified afferent information to be dispersed, whereas polysynaptic neurons undergo time-dependent inhibition.