geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Contribution of oxygen-sensitive neurons of the rostral ventrolateral medulla to hypoxic cerebral vasodilatation in the rat


, : Contribution of oxygen-sensitive neurons of the rostral ventrolateral medulla to hypoxic cerebral vasodilatation in the rat. Journal of Physiology 495: 201-216

1. We sought to determine whether hypoxic stimulation of neurons of the rostral ventrolateral reticular nucleus (RVL) would elevate regional cerebral blood flow (rCBF) in anaesthetized paralysed rats. 2. Microinjection of sodium cyanide (NaCN; 150-450 pmol) into the RVL rapidly (within 1-2 s), transiently, dose-dependently and site-specifically elevated rCBF1 measured by laser Doppler flowmetry, by 61.3 +/- 22.1% (P < 0.01), increased arterial pressure (AP; +30 +/- 8 mmHg; P < 0.01)1 and triggered a synchronized 6 Hz rhythm of EEG activity. 3. Following cervical spinal cord transection, NaCN and also dinitrophenol (DNP) significantly (P < 0.05) elevated rCBF and synchronized the EEG but did not elevate AP; the response to NaCN was attenuated by hyperoxia and deepening of anaesthesia. 4. Electrical stimulation of NaCN-sensitive sites in the RVL in spinalized rats increased rCBF measured autoradiographically with 14C iodoantipyrine (Kety method) in the mid-line thalamus (by 182.3 +/- 17.2%; P < 0.05) and cerebral cortex (by 172.6 +/- 15.6%; P < 0.05) regions, respectively, directly or indirectly innervated by RVL neurons, and in the remainder of the brain. In contrast regional cerebral glucose utilization (rCGU), measured autoradiographically with 14C-2-deoxyglucose (Sokoloff method), was increased in proportion to rCBF in the mid-line thalamus (165.6 +/- 17.8%, P < 0.05) but was unchanged in the cortex. 5. Bilateral electrolytic lesions of NaCN sensitive sites of RVL, while not altering resting rCBF or the elevation elicited by hypercarbia (arterial CO2 pressure, Pa,CO2, approximately 69 mmHg), reduced the vasodilatation elicited by normocapnic hypoxaemia (arterial O2 pressure, Pa,O2, approximately 27 mmHg) by 67% (P < 0.01) and flattened the slope of the Pa,O2-rCBF response curve. 6. We conclude that the elevation of rCBF produced in the cerebral cortex by hypoxaemia is in large measure neurogenic, mediated trans-synaptically over intrinsic neuronal pathways, and initiated by excitation of oxygen sensitive neurons in the RVL.

US$19.90

PMID: 8866363

DOI: 10.1113/jphysiol.1996.sp021585


Other references

Yamada, J.; Phillips, J.L.; Patel, S.; Goldfien, G.; Calestagne-Morelli, A.; Huang, H.; Reza, R.; Acheson, J.; Krishnan, V.V.; Newsam, S.; Gopinathan, A.; Lau, E.Y.; Colvin, M.E.; Uversky, V.N.; Rexach, M.F., 2011: A bimodal distribution of two distinct categories of intrinsically disordered structures with separate functions in FG nucleoporins. Nuclear pore complexes (NPCs) gate the only conduits for nucleocytoplasmic transport in eukaryotes. Their gate is formed by nucleoporins containing large intrinsically disordered domains with multiple phenylalanine-glycine repeats (FG domains). In...

Rajiv Rai, 1996: To study the efficacy of different nursery raising techniques in neem (Azadirachta indica). The first part of the paper discusses published work which indicates that neem seeds are short lived, being viable for a period of only 8-10 days from the date of collection, so that they are difficult to propagate in the nursery; work on prolongi...

Porta, David James, 2001: Enhancement of gross anatomy lectures with videos of traumatic injury A simple method of clinical correlation. Amazingly, some students are not completely enamored with a pure lecture format for the study of anatomy! In such cases, incorporation of experimental and/or real-world traumatic injury videos may invigorate both the class and the lecturer. The us...

Tjabringa, G.Sandra.; Vos, J.B.; Olthuis, D.; Ninaber, D.K.; Rabe, K.F.; Schalkwijk, J.; Hiemstra, P.S.; Zeeuwen, P.L.J.M., 2005: Host defense effector molecules in mucosal secretions. Mucosal secretions contain a range of defense effector molecules including antimicrobial peptides and proteinase inhibitors. These molecules play a central role in host defense against infection, and in a variety of immune and inflammatory reactio...

Luzier, J.M.; Summerfelt, R.C., 1993: A review of the ecology and life history of clam shrimps orders Spinicaudata, Laevicaudata, formerly order Conchostraca Branchiopoda. Aspects of clam shrimp life history and ecology are reviewed. Clam shrimp are small crustaceans of the orders Spinicaudata and Laevicaudata, and they superficially resemble small, bivalve mollusks of the family Sphaeriidae. They are common inhabit...

Welt, L.G.; Burnett, C.H., 1968: Charles Hoyt Burnett. 1913-1967. Transactions of the Association of American Physicians 81: 8-8

Dees, S.C., 1953: Electro-encephalography in allergic epilepsy. Southern Medical Journal 46(6): 618-620

Paniushkina, S.V., 1980: Neurophysiological aspects of psychopharmacology (a review of the foreign literature). Farmakologiia i Toksikologiia 43(6): 736-740

Khan, M.Ullah., 2013: Is there a role for TENS application in the control of diabetes mellitus in insulin-dependent patients?. An 80-year-old man with insulin-dependent diabetes mellitus presented to the hospital with low back pain. He was initially managed with non-steroidal anti-inflammatory drugs, tramadol and epidural steroid injection. Transcutaneous electrical nerve...

Ebert, J.J.; Contreras, P.; Saelzer, P., 1972: Influence of a teaser bull on puerperium and fertility in dairy cows. Time of uterine involution, regression of corpora lutea and return of ovarian activity were compared in 2 groups of 25 cows each, animals in one group being joined with a teaser bull, while those in the other served as controls. Differences in fav...