Catecholamine projections to the spinal cord in the rat and their relationship to central cardiovascular neurons.

The organization of the neuroanatomical substrate which provides the supraspinal catecholaminergic innervation of the upper thoracic spinal cord in the rat was studied by means of retrograde labelling of neurons with primuline and other dyes, combined with simultaneous catecholamine fluorescence (FAGLU-method). It was shown that spinally projecting catecholaminergic neurons lie predominantly in the A6 and A11 groups, while a minority of these neurons are also located in the A1/C1 and A5 groups. The number of catecholamine-containing neurons in the A11 group in the rat was estimated to be 173 +/- 4. Most of them (up to 86%) were retrogradely labelled with primuline. The possible functional role of dopaminergic diencephalospinal, noradrenergic pontospinal, and adrenergic bulbospinal neuronal systems in cardiovascular control is discussed.

[Distribution in the diencephalon of the rat of retrogradely primuline-labelled dopamine-containing neurons forming spinal projections]. / Raspredelenie v promezhutochnom mozge krysy retrogradno mechennykh primulinom dofaminsoderzhashchikh neironov, obrazuiushchikh spinal'nye proektsii.

Distribution of primuline-labeled dopamine-containing neurons in the rat diencephalon following injection of fluorochrome into upper thoracic spinal cord was studied using a combination of catecholamine fluorescence method and retrograde cell-labeling. It was shown that only neurons of group A11 located in the dorsal hypothalamus and caudal thalamus give rise to the spinal projections. Non-catecholamine cells were also labeled in this region. Group A11 comprised 173 +/- 4 catecholamine-containing neurons. Most of them (up to 86%) were retrogradely labeled with primuline. The number of labeled dopamine-containing neurons increased in the rostro-caudal direction. Possible functional role of the dopaminergic diencephalon-spinal neuronal system is discussed.

[Bulbar and pontine sources of catecholaminergic innervation of the spinal cord of the rat studied using monoamine fluorescence and retrograde labeling technics]. / Bul'barnye i mostovye istochniki katekholaminergicheskoi innervatsii spinnogo mozga krysy, izuchennye s pomoshch'iu metodov fluorestsentsii monoaminov i retrogradnogo mecheniia.

Organization of the neuroanatomical substrate providing the supraspinal catecholaminergic innervation of upper thoracic spinal cord in rat was studied by the retrograde neuronal labelling by means of primuline and HRP combined with simultaneous catecholamine fluorescence. It was shown that the pontine catecholaminergic neurons located within the ventral part of nucleus locus coeruleus (group A6), reticular formation (subcoeruleus, group A7) as well as lateral to the superior olivary complex (group A5) project to the spinal cord. At the same time there are only few neurons located within the rostral part of the medullary catecholaminergic group A1 which give rise to the funicular projections. It is suggested that the pontine catecholaminergic neurons taking part in the spinal innervation are noradrenaline-containing neurons whereas those of medulla oblongata--adrenaline-containing ones.