Elsevier

Brain Research

Volume 634, Issue 2, 21 January 1994, Pages 227-234
Brain Research

Monosynaptic excitation of preganglionic vasomotor neurons by subretrofacial neurons of the rostral ventrolateral medulla

https://doi.org/10.1016/0006-8993(94)91925-9Get rights and content

Abstract

Extracellular single unit recordings were made from barosensitive neurons in the subretrofacial nucleus (SRF) of the rostral ventrolateral medulla in chloralose-anaesthetised cats. At the same time, single preganglionic neuron activity was recorded from filaments of the cervical sympathetic trunk (CST); barosensitive units were selected for study. Evidence for monosynaptic connections between the two neuron groups was sought by cross-correlation analysis of their ongoing activity. Cross-correlograms of 16/16 SRF/CST neuron pairs showed a broad peak (100–200ms wide), reflecting the synchronising action of arterial baroreceptors on both neurons' activity. Two of the 16 cross-correlograms additionally showed a robust, statistically significant, narrow peak of a single 2 ms bin width, providing the first physiological demonstration that ventrolateral medullary neurons monosynaptically excite preganglionic sympathetic neurons. Deductions are made about the strength, convergence and divergence of the connection.

References (37)

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