Ultrastructural transneuronal degeneration study of axonal elements within the paratrigeminal nucleus in sinoaortic deafferented rats.
OBJECTIVE
Morphological study that searched to authenticate the presence of sinoaortic baroreceptor inputs within the dorsolateral medullary nucleus under electron microscopy analysis.


METHODS
After a 5-day survival period, 9 baroreceptor-denervated rats deeply anaesthetized with equithesin were transcardially perfused and their brains were histologically processed.


RESULTS
The neuronal cytoarchitecture of the paratrigeminal nucleus comprehends afferent projections from other nuclei that have a distributive character regarding visceral and nociceptive functions in the cardiovascular reflex integration response.


CONCLUSIONS
The medial portion of the nucleus receives afferent projections of the rostral ventrolateral medulla, as shown by retrograde neurotracing studies. The present results show that the medial extent of the paratrigeminal nucleus contains degenerated axoplasmic cellular components in sinoaortic deafferented rats. The number of degenerated axonal fibers was also larger in this area of the nucleus.
Instituto do Cérebro, Hospital Israelita Albert Einstein.
Cristofer André
CA
Caous
Ricardo Luís
RL
Smith
Edna Freymuller
EF
Haapalainen
Charles Julian
CJ
Lindsey
D000818:Animals; D001011:Aorta / Q000294:innervation / Q000648:ultrastructure; D001341:Autonomic Nervous System / Q000502:physiology / Q000648:ultrastructure*; D001369:Axons / Q000502:physiology* / Q000648:ultrastructure; D008297:Male; D008855:Microscopy, Electron, Scanning; D009410:Nerve Degeneration / Q000473:pathology* / Q000503:physiopathology; D009475:Neurons, Afferent / Q000502:physiology / Q000648:ultrastructure*; D011311:Pressoreceptors / Q000502:physiology / Q000648:ultrastructure*; D051381:Rats; D017208:Rats, Wistar; D014279:Trigeminal Nucleus, Spinal / Q000502:physiology / Q000648:ultrastructure*