scholarly journals Critique of ‘Control of arterialPCO2by somatic afferents’

2006 ◽  
Vol 572 (3) ◽  
pp. 897-898 ◽  
Author(s):  
Yunguo Yu ◽  
Chi-Sang Poon
Keyword(s):  
Somatic Afferents

Effect of dorsal root section on the arrhythmias associated with coronary occlusion

1976 ◽  
Vol 231 (3) ◽  
pp. 923-928 ◽  
Author(s):  
PJ Schwartz ◽  
RD Foreman ◽  
HL Stone ◽  
AM Brown
Keyword(s):  
Coronary Artery ◽  
Dorsal Root ◽  
Coronary Occlusion ◽  
Absolute Number ◽  
Root Section ◽  
Dorsal Roots ◽  
Somatic Afferents ◽  
Afferent Fibers ◽  
Surgical Preparation ◽  
Ectopic Beats

In anesthetized vagotomized dogs and cats the circumflex and/or the anterior descending coronary artery were briefly occluded (5-90 s), and ectopic beats occurring during the occlusion and for 60 s following release were counted. When arrhythmias were regularly produced for a given occlusion, the dorsal roots from C8 to T5 were transected and the occlusions were repeated. Dorsal root section produced minor changes in heart rate and blood pressure. Dogs and cats did not differ in their responses. Dorsal root section was performed in eight animals and decreased the absolute number of ectopic beats by 63 +/- 19% compared to control values (P less than 0.05). In four animals the effect on ectopic beats produced by repeated occlusions without dorsal root section was investigated and found to be increased by 35 +/- 24% compared to contrl values. Most of the somatic afferents contained in the dorsal roots were damaged by the surgical preparation. Therefore, repeated occlusions and interruption of somatic afferents do not appear to have influenced our results. The arrhythmogenic interaction between the local effects of myocardial ischemia and the sympathetic activity, whose outlow contained in the ventral roots remained intact, was still possible after dorsal root section and this explains why ectopic beats were reduced but not almost suppressed as is usually the case after bilateral stellectomy. We conclude that dorsal root section reduces the number of ectopic beats associated with short-lasting coronary artery occlusions and that the most likely mechanism is the interruption of the cardiocardiac sympathetic reflex which depends upon afferent fibers running through the dorsal roots.

scholarly journals Inhibition of micturition reflex by activation of somatic afferents in posterior femoral cutaneous nerve

2012 ◽  
Vol 590 (19) ◽  
pp. 4945-4955 ◽  
Author(s):  
Changfeng Tai ◽  
Bing Shen ◽  
Abhijith D. Mally ◽  
Fan Zhang ◽  
Shouguo Zhao ◽  
...  
Keyword(s):  
Cutaneous Nerve ◽  
Micturition Reflex ◽  
Somatic Afferents ◽  
Femoral Cutaneous Nerve ◽  
Posterior Femoral Cutaneous Nerve

Excitatory convergence of periaqueductal gray and somatic afferents in the solitary tract nucleus: role for neurokinin 1 receptors

2005 ◽  
Vol 288 (1) ◽  
pp. R262-R269 ◽  
Author(s):  
Pedro Boscan ◽  
Julian F. R. Paton
Keyword(s):  
Spinal Cord ◽  
Brachial Plexus ◽  
Cervical Spinal Cord ◽  
Periaqueductal Gray ◽  
Afferent Input ◽  
Baroreceptor Reflex ◽  
Peak Discharge ◽  
Discharge Frequency ◽  
Solitary Tract ◽  
Somatic Afferents

Our previous studies (Boscan P, Kasparov S, and Paton JF. Eur J Neurosci 16: 907–920, 2002) showed that activation of somatic afferents attenuated the baroreceptor reflex via neurokinin type 1 (NK1) and GABAA receptors within the nucleus of the solitary tract (NTS). The periaqueductal gray matter (PAG) can also depress baroreceptor reflex function and project to the NTS. In the present study, we have tested the possibility that the dorsolateral (dl)-PAG projects to the NTS neurons that also respond to somatic afferent input. In an in situ, arterially perfused, unanesthetized decerebrate rat preparation, somatic afferents (brachial plexus), cervical spinal cord, and dl-PAG were stimulated electrically, whereas NTS neurons were recorded extracellularly. From 45 NTS neurons excited by either brachial plexus or dl-PAG stimulation, 41 received convergence excitatory inputs from both afferents. Onset latency and evoked peak discharge frequency from brachial plexus afferents were 39.4 ± 4.7 ms and 10.7 ± 1.1 Hz, whereas this was 43.9 ± 6.4 ms and 7.9 ± 1 Hz, respectively, following dl-PAG stimulation. As revealed by using a paired pulse stimulation protocol, monosynaptic connections were found in 9 of 36 neurons tested from both spinal cord and dl-PAG. We tested NK1-receptor sensitivity in 38 neurons that received convergent inputs from brachial plexus/PAG. Fifteen neurons were sensitive to selective antagonism of NK1 receptors. CP-99994, the NK1 antagonist, failed to alter ongoing firing activity but reduced the evoked peak discharge frequency following stimulation of both brachial plexus (from 12.3 ± 1.8 to 7.2 ± 1.3 Hz; P < 0.01) and PAG (from 7.8 ± 1.5 to 4.5 ± 1 Hz; P < 0.01). We conclude that 1) somatic brachial and PAG afferents can converge onto single NTS neurons; 2) this convergence occurs via either direct or indirect pathways; and 3) NK1 receptors are activated by some of these inputs.

Synaptic effects of contralateral somatic afferents on spinal motoneurons

1972 ◽  
Vol 3 (4) ◽  
pp. 316-321 ◽  
Author(s):  
S. A. Evdokimov ◽  
V. I. Saf'yants
Keyword(s):  
Spinal Motoneurons ◽  
Somatic Afferents ◽  
Synaptic Effects
Sign in / Sign up

Export Citation Format

Share Document