We investigated a neural reflex that controls the strength of inflammatory responses to immune challenge - reflex. In anaesthetized rats challenged with intravenous lipopolysaccharide (LPS, 60 μg kg(-1)), we found strong increases in plasma levels key mediator tumour necrosis factor α (TNFα) 90 min later. Those were unaffected by previous bilateral cervical vagotomy, but enhanced approximately 5-fold if greater splanchnic sympathetic nerves had been cut. Sham surgery no effect, and...

1. Electrophysiological techniques have been used to locate the origin of preganglionic vagal motoneurones supplying heart cat. 2. The right cardiac branches were identified anatomically and their ability slow was assessed by electrical stimulation. Control experiments revealed that contamination bronchomotor oesophageal efferent fibres likely be small. 3. Fifty-seven neurones in medulla activated antidromically on stimulating at up 5 times threshold for slowing. They had axons with...

1. A study has been made of eighty-four cells in the cat's nucleus ambiguus whose axons projected to cardiac (seventy-four) and pulmonary (ten) branches right vagus. Their axonal conduction velocities were all range B fibres (2.8-15.5 m/sec).2. Pulmonary branch projecting neurones usually spontaneously active (nine out ten) fired phase with inspiration. activity showed no pulse modulation.3. Ten had properties indistinguishable from those neurones. Inspiratory-firing either are believed be...

1. Simultaneous recordings were made from postganglionic sympathetic fibres supplying hindlimb skin and skeletal muscle in chloralose‐anaesthetized, artificially ventilated cats. Single‐fibre activity was either isolated by dissection or discriminated few‐fibre preparations of fascicles the left superficial peroneal sural nerve (innervating hairy skin) common muscle). Vasoconstrictor identified their spontaneous as well responses to stimulation lumbar chain changes baroreceptor activity. The...

1. A study has been made of twenty-three cardiac vagal motoneurones (c.v.m.s) in the nucleus ambiguus chloralose-anaesthetized cats.2. C.v.m.s were identified as described previously (McAllen & Spyer, 1978). They either spontaneously active (five units) or induced to fire by ionophoresis DL-homocysteic acid (DLH). Evidence is presented that above threshold, DLH dose not critical for ability show a baroreceptor influence.3. The influence baroreceptors was determined plotting pulse-triggered...

The 'inflammatory reflex' acts through efferent neural connections from the central nervous system to lymphoid organs, particularly spleen, that suppress production of inflammatory cytokines. Stimulation vagus has been shown inflammation in a manner dependent on spleen and splenic nerves. does not innervate so synaptic connection vagal preganglionic neurons sympathetic postganglionic was suggested. We tested this idea rats. In preparatory operation, anterograde tracer DiI injected...

Electrical stimulation within the medulla of cats revealed that myelinated primary afferent fibres sinus nerve terminated immediate vicinity tractus solitarius and its nucleus. 2. The activity neurones this area was also evoked on stimulation, although few (17%) were activated a latency compatible with monosynaptic excitation. Additional projections over polysynaptic pathways have been shown to parahypoglossal nucleus ambiguus. 3. These three areas contain whose enhanced by baroreceptor...

Cardiac vagal tone is a strong predictor of health, although its central origins are unknown. Respiratory-linked fluctuations in cardiac give rise to respiratory sinus arryhthmia (RSA), with maximum the post-inspiratory phase respiration. In present study, we investigated whether modulation intrinsically linked control using unanaesthetized working heart-brainstem preparation rat. Abolition post-inspiration, achieved by inhibition pontine Kolliker-Fuse nucleus, removed peaks efferent...

1. An investigation has been made into the connexions between carotid body chemoreceptors and dorsal respiratory neurones of cat's medulla.2. In confirmation previous work these were found to be all inspiratory in firing pattern fall two categories, Ralpha (forty-four units) which fire only with central rhythm Rbeta (thirty-two neurones) that are also excited by lung inflation. Both categories shown stimuli delivered bodies during inspiration but, a single exception, not expiration.3. When...

The lack of noninvasive approaches to measure cardiac sympathetic nerve activity (CSNA) has driven the development indirect estimates such as low-frequency (LF) power heart rate variability (HRV). Recently, it been suggested that LF HRV can be used estimate baroreflex modulation period (HP) rather than tone. To test this hypothesis, we measured CSNA, HP, blood pressure (BP), and sensitivity (BRS) estimated with modified Oxford technique, in conscious sheep pacing-induced failure healthy...

AEI Aquaculture Environment Interactions Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 1:245-257 (2011) - DOI: https://doi.org/10.3354/aei00024 Gill disorders in marine-farmed salmon: ­investigating role of hydrozoan jellyfish Emily J. Baxter1,2,*, Hamish D. Rodger3, Rob McAllen2, Thomas K. Doyle1 1Coastal and Marine Research Centre, Environmental Institute, University College Cork, Naval...

Vagal nerve stimulation is widely used therapeutically but the fiber groups activated are often unknown. Aim: To establish a simple protocol to define stimulus thresholds for vagal A, B and C fibers. Methods: The intact left or right cervical vagus was stimulated with 0.1 ms pulses in spontaneously breathing anesthetized rats. Heart respiratory rate responses were recorded. subsequently cut distally, mass action potentials same stimuli Results: Stimulating at either 50 Hz 2 s 10...