Medullospinal sympathoexcitatory neurons in normotensive and spontaneously XXXX @entity35 .

@entity101 @entity1508 @entity35 @entity3389 @entity551
Aortic depressor nerve discharge (AND), lumbar @entity3389 ( @entity3389 ), and single-unit activity of medullospinal pressure-sensitive neurons of nucleus paragigantocellularis lateralis (PGCL neurons) were recorded in @entity1508 -anesthetized 16-wk-old spontaneously @entity101 @entity35 (SHRs) and normotensive @entity35 -Kyoto (WKY) @entity35 . The relationship between these variables and mean arterial pressure (MAP) was investigated. The gain of baroreceptor afferents was not significantly different between the strains, but corner MAP (intersection between linear ascending portion of curve and noise) was 38 mmHg higher in SHRs. The relationship between @entity3389 and MAP and that between PGCL neuronal activity and MAP were both characterized by a plateau (maximal activity) at low MAP followed by a linear reduction reaching zero at a level called cutoff MAP. The theoretical intersection between the plateau and the linear decremental portion of these curves was defined as a corner MAP. Values of corner MAP determined at the three levels (AND, @entity3389 , PGCL) were identical in a given strain and reset by a common value in SHRs (38-40 mmHg). The gain of baroreceptor reflex measured at all three sites as the slope of the linear incremental (AND) or decremental (PGCL and sympathetic chain) portion of the activity-MAP relationship was the same in WKY @entity35 and in SHRs. @entity551 measured in PGCL was identical to that measured in peripheral sympathetic system for a given strain. There was no significant difference in maximal discharge rate of PGCL neurons nor in lumbar @entity3389 and no interstrain difference in the proportion of @entity3389 that was suppressible by arterial baroreceptor feedback.(ABSTRACT TRUNCATED AT 250 WORDS)
