|
|
||||||||
Post-synaptic responses evoked in neurones of the nucleus tractus solitarius by electrical stimulation of the carotid sinus, aortic and vagal nerves, alone or in combination, have been studied in anaesthetized cats using both extracellular and intracellular recording techniques. A total of 292 neurones received an input from at least one of the three nerves tested. The activity of the large majority of these cells (249) could only be shown to be altered by stimulation of one of these nerves and in 222 of these cases this was an excitatory response. These responses showed the expected post-synaptic characteristics including temporal summation and, in intracellular records, a summation of evoked excitatory post-synaptic potentials (e.p.s.p.s). The minimum latency to onset of these responses was variable, both for individual cells and for the population as a whole and varied within the range 2-124 ms. In a small number of cells (twenty-seven), the input was purely inhibitory in nature. In neurones showing a tonic discharge this produced a decrease in the rate of firing. This influence was most marked in intracellular records where membrane hyperpolarizations were noted. Again, the latency to onset was variable, in the range 4-27 ms. Convergent inputs from two or more of the nerves were identified in forty-three neurones. The effects of these were always excitatory. They could be observed both as a facilitation of spike activity recorded extracellularly and as summation of subliminally evoked e.p.s.p.s recorded intracellularly. On the basis of threshold voltages and latency to onset, the afferents to these neurones are indistinguishable from those providing an exclusive input. It can be concluded that at least some of the neurones in the nucleus tractus solitarius and its vicinity receive inputs from more than one source. The implications of these observations on the role of this brain-stem area in cardiorespiratory reflexes is discussed.
This article has been cited by other articles:
![]() |
T. W. Bailey, S. M. Appleyard, Y.-H. Jin, and M. C. Andresen Organization and Properties of GABAergic Neurons in Solitary Tract Nucleus (NTS) J Neurophysiol, April 1, 2008; 99(4): 1712 - 1722. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. M. Appleyard, D. Marks, K. Kobayashi, H. Okano, M. J. Low, and M. C. Andresen Visceral Afferents Directly Activate Catecholamine Neurons in the Solitary Tract Nucleus J. Neurosci., November 28, 2007; 27(48): 13292 - 13302. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. C. Salgado, A. R. Barale, J. A. Castania, B. H. Machado, M. W. Chapleau, and R. Fazan Jr. Baroreflex responses to electrical stimulation of aortic depressor nerve in conscious SHR Am J Physiol Heart Circ Physiol, January 1, 2007; 292(1): H593 - H600. [Abstract] [Full Text] [PDF] |
||||
![]() |
C.-Y. Chen, A. C. Bonham, C. G. Plopper, and J. P. Joad Plasticity in Respiratory Motor Control: Selected Contribution: Neuroplasticity in nucleus tractus solitarius neurons after episodic ozone exposure in infant primates J Appl Physiol, February 1, 2003; 94(2): 819 - 827. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. W. Doyle, T. W. Bailey, Y.-H. Jin, and M. C. Andresen Vanilloid Receptors Presynaptically Modulate Cranial Visceral Afferent Synaptic Transmission in Nucleus Tractus Solitarius J. Neurosci., September 15, 2002; 22(18): 8222 - 8229. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. W. Taylor, D. Jordan, and J. H. Coote Central Control of the Cardiovascular and Respiratory Systems and Their Interactions in Vertebrates Physiol Rev, July 1, 1999; 79(3): 855 - 916. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. C. Yen, J. Y. H. Chan, and S. H. H. Chan Differential Roles of NMDA and Non-NMDA Receptors in Synaptic Responses of Neurons in Nucleus Tractus Solitarii of the Rat J Neurophysiol, June 1, 1999; 81(6): 3034 - 3043. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. Fan and M. C. Andresen Differential frequency-dependent reflex integration of myelinated and nonmyelinated rat aortic baroreceptors Am J Physiol Heart Circ Physiol, August 1, 1998; 275(2): H632 - H640. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. K. W. Chan and P. E. Sawchenko Organization and Transmitter Specificity of Medullary Neurons Activated by Sustained Hypertension: Implications for Understanding Baroreceptor Reflex Circuitry J. Neurosci., January 1, 1998; 18(1): 371 - 387. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |