Efferent projections from the retrochiasmatic area to the median eminence and to the pars nervosa of the hypophysis with special reference to the A15 dopaminergic cell group in the sheep

1995 ◽  
Vol 281 (3) ◽  
pp. 561-567 ◽  
Author(s):  
V�ronique Gayrard ◽  
Jean-Claude Thi�ry ◽  
Jean Thibault ◽  
Yves Tillet
Keyword(s):  
Special Reference ◽  
Median Eminence ◽  
Cell Group ◽  
Dopaminergic Cell ◽  
Pars Nervosa ◽  
Efferent Projections ◽  
Retrochiasmatic Area

Medullary pathways mediating depressor responses from Na(+)-sensitive sites in nucleus of the solitary tract

1997 ◽  
Vol 272 (1) ◽  
pp. R126-R133 ◽  
Author(s):  
S. L. Hochstenbach ◽  
J. Ciriello
Keyword(s):  
Area Postrema ◽  
Cardiovascular Response ◽  
Nucleus Ambiguus ◽  
Ventrolateral Medulla ◽  
Cell Group ◽  
Motor Nucleus ◽  
Solitary Tract ◽  
Male Wistar Rats ◽  
Efferent Projections ◽  
Series Of Experiments

Two series of experiments were done in male Wistar rats to investigate the medullary pathways that mediate the depressor responses from sodium-sensitive sites in the nucleus of the solitary tract (NTS). In the first series, the anterograde tract tracer Phaseolus vulgaris leucoagglutinin (PHA-L) was iontophoresed unilaterally at sites in the NTS at which microinjections (20 nl) of a 154-175 mM NaCl solution elicited depressor responses. PHA-L injection sites were found to be localized within the medial subnucleus of the NTS (Sm). In the medulla, PHA-L-labeled fibers and presumptive terminal boutons were observed bilaterally, but with an ipsilateral predominance, throughout the rostrocaudal extent of the NTS the dorsal motor nucleus of the vagus, area postrema, the ventrolateral medulla (VLM), and nucleus ambiguus. The pontine region, containing the A5 catecholaminergic cell group and the parabrachial nucleus, also received projections from Sm. In the second series of experiments, the effect of blocking synaptic transmission in VLM with cobalt chloride (CoCl2; 5 mM, 100 nl) on the cardiovascular response elicited by microinjection (20 nl) of hypertonic saline (154-175 mM) into the ipsilateral Sm was investigated in the alpha-chloralose-anesthetized, paralyzed, and artificially ventilated rat. Microinjection of CoCl2 into VLM, at sites shown in the previous study to receive efferent projections from Sm, significantly attenuated the depressor (60%) and bradycardic (80%) responses to stimulation of Sm. These data indicate that the sodium-sensitive region of the caudal Sm innervates VLM neurons and suggest that these VLM neurons are involved in mediating the depressor and bradycardic responses elicited by changes in the extracellular concentration of sodium.

Dopaminergic cell group A8 in the monkey: Anatomical organization and projections to the striatum

1999 ◽  
Vol 414 (3) ◽  
pp. 334-347 ◽  
Author(s):  
C. Fran�ois ◽  
J. Yelnik ◽  
D. Tand� ◽  
Y. Agid ◽  
E.C. Hirsch
Keyword(s):  
Cell Group ◽  
Dopaminergic Cell
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