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PubMed1992

Specialized functional pathways are the building blocks of the autonomic nervous system.

The autonomic nervous system supplies each type of target organ via separate pathways which consist of sets of pre- and postganglionic neurones with distinct patterns of reflex activity. This has been firmly established for the lumbar sympathetic nervous system to skin, skeletal muscle and viscera, for the thoracic sympathetic outflow to the head and for several parasympathetic systems. In principle, that was already known by Langley. The specificity of the messages that these pathways transmit from the central nervous system arises from integration within precisely organized pathways in the neuraxis. The messages travel along discrete functional pathways and are transmitted to the target tissues via close neuroeffector junctions. Integration in the periphery occurs within each pathway, both in ganglia and at the level of the effector organs. We still need to understand how the central messages get through without distortion and how they control the diverse functions of the vasculature and viscera.

Animals↗
PubMed2003

The threat of predictable and unpredictable pain: differential effects on central nervous system processing?

Central nervous system performance is disrupted by pain and by the threat of pain. It is not known whether disruption caused by the threat of pain is dependent on the likelihood of pain occurring. We hypothesised that when a painful stimulus is possible but unpredictable central nervous system performance is reduced, but when the pain is predictable and unavoidable it is not. Sixteen healthy subjects performed a reaction time task during predictable and unpredictable conditions (100% and 50% probability of pain, respectively). Group data showed increased reaction time with the threat of pain by 50 ms (95% CI 16 to 83 ms) for the predictable condition and 46 ms (95% CI 12 to 80 ms) for the unpredictable condition (p lt 0.01 for both), but there was no difference between predictable and unpredictable conditions (p = 0.41). However, individual data showed that there was a differential effect in 75% of subjects (p lt 0.05 for all) and that there was a greater effect of predictable pain for some subjects and a greater effect of unpredictable pain for others. Reaction time was related to reported anxiety (r = 0.49, p = 0.02 for both conditions). The predictability of a painful stimulus may have a differential effect on central nervous system performance within individuals, but anxiety about the impending pain appears to be important in determining this effect.

Adult↗
PubMed1987

Interrelationships between the heart and central nervous system: localization of neuro-transmitters and imaging of their associated nuclei, including the raphe nuclei & the locus coeruleus, as well as the imaging of the heart and its representation areas in slices of the human central nervous system using the "Bi-Digital O-Ring Test" imaging method.

Using microscopic slides of specific tissues from the human body or pure substances including neuro-transmitters such as serotonin, dopamine, norepinephrine, etc., as reference control substances in the Bi-Digital O-Ring Test Molecular Identification Method, the author was able to localize and image normal and abnormal internal organs, and to localize and trace the distribution of neurotransmitters in the different parts of the central nervous system. Using microscopic slides of different parts of the heart, we were able to image the outline of the heart as well as the SA node, AV node, tricuspid valve, mitral valve, aortic valve, pulmonary valve, coronary arteries, and aorta and its branches, including the vertebral arteries, without using any bulky or expensive imaging instruments. Using serotonin as a reference control substance on the different parts of the central nervous system, it was possible to demonstrate the 6 well-known raphe nuclei and the locus coeruleus (which contains serotonin & norepinephrine), as well as the distribution of serotonin in the cerebrum and the cerebellum, all of which closely resembled previously published well-known neuroanatomical structures and distributions of neurotransmitters. As an extension of this work, possible representations of different internal organs on the central nervous system were examined using microscopic slides of different internal organs as reference control substances. The results indicated that the entire heart is represented primarily in the medulla oblongata, and that the SA node and the upper half of the left atrium are represented in the caudal end of the pons; the right side of the heart (i.e. R-atrium, AV node, tricuspid valve, R-ventricle) is represented on the right side of the medulla oblongata, and the left side of the heart (i.e. lower half of the L-atrium, mitral valve, L-ventricle) is represented on the left side of the medulla oblongata, and the upper half of the left atrium is represented in the caudal end of the left side of the pons. The bottoms of the ventricles are located near the spinal cord. Furthermore, the right and the left sides of the heart are represented in specific areas of each side of the right and left hemispheres of the cerebral cortex, and there are connecting pathways between the representation areas of identical parts of the heart, through the corpus callosum and other neuro-pathways.

Central Nervous System↗
PubMed1989

Electrophysiology of ganglionic transmission in the sympathetic nervous system.

The sympathetic nervous system contributes to the regulation and control of a great number of body functions. A considerable fraction of preganglionic fibers are constantly discharging nerve impulses, and this tonic activity is responsible for a number of sustained bodily conditions. These tonic sympathetic discharges are of central origin and may be decreased by inhibition or augmented by excitation of the central neural mechanisms in control of the relevant preganglionic neurons. Certain other sympathetic paths become active only when special conditions lead to excitation of their central connections. The effect of the activity of preganglionic fibers on the different target organs, however, does not depend entirely on central regulatory influences. The sympathetic ganglia play a significant role processing and integrating the information arriving from the central nervous system and controlling the output to the target organs. In this context, the different potentials described above constitute the basis for the integrative process to occur. We now have substantial information about the basic biophysical events associated with different electrical events in the sympathetic ganglia. Very little is known, however, about how they operate in an integrative manner to control specific functions. The control of sympathetic responses during surgical stimulation is an important goal of general anesthesia. General anesthetics may operate to produce this effect at both central and peripheral levels. The sympathetic ganglion as a peripheral synapse, with basic integrative properties similar to the complex central nervous system, is a model still not sufficiently exploited to understand mechanisms by which general anesthetics control sympathetic response. The relevance of the findings described above in a variety of clinical situations, such as stress, hypertension, exercise, and anesthesia, remains to be studied.

Animals↗
PubMed1988

Contribution of the renin-angiotensin system and of the sympathetic nervous system to blood pressure homeostasis during chronic restriction of sodium intake.

In a previous paper, we showed that during a long-term, moderate restriction in sodium intake, sympathetic nervous system activity was only transiently stimulated, whereas a sustained rise of plasma renin activity occurred. However, the contribution from stimulation of the renin-angiotensin system in the maintenance of blood pressure homeostasis during a low-salt diet is still unclear. To investigate this issue, in eight normal subjects blood pressure, heart rate, plasma catecholamines, renin activity, and aldosterone were measured during normal sodium intake (150 mEq/d), after converting-enzyme inhibition (enalapril 20 mg/d po), and during one month of sodium intake restriction (50 mEq/d) associated with chronic inhibition of converting-enzyme (CEI). During a low-salt diet with CEI, plasma renin activity rose significantly as a result of CEI. In addition, even in the presence of a marked and sustained increase in plasma norepinephrine and in upright heart rate, a decrease in blood pressure was observed in all the measurements performed during the course of the study as compared to the control values. Our findings support the hypothesis that renin-angiotensin system activation plays an important role in the maintenance of blood pressure homeostasis during a low-salt diet. In fact, in the presence of an effective blockade of angiotensin II formation, blood pressure is decreased, despite the concurrent, sustained stimulation of the sympathetic nervous system.

Adolescent↗
PubMed2005

Central nervous system injury triggers hepatic CC and CXC chemokine expression that is associated with leukocyte mobilization and recruitment to both the central nervous system and the liver.

The administration of interleukin-1beta to the brain induces hepatic CXC chemokine synthesis, which increases neutrophil levels in the blood, liver, and brain. We now show that such hepatic response is not restricted to the CXC chemokines. CCL-2, a CC chemokine, was released by the liver in response to a tumor necrosis factor (TNF)-alpha challenge to the brain and boosted monocyte levels. Furthermore, a clinically relevant compression injury to the spinal cord triggered hepatic chemokine expression of both types. After a spinal cord injury, elevated CCL-2 and CXCL-1 mRNA and protein were observed in the liver by TaqMan reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay as early as 2 to 4 hours. Simultaneously, we observed elevated levels of these chemokines and circulating leukocyte populations in the blood. Leukocytes were recruited to the liver at this early stage, whereas at the site of challenge in the central nervous system, few were observed until 24 hours. Artificial elevation of blood CCL-2 triggered dose-dependent monocyte mobilization in the blood and enhanced monocyte recruitment to the brain after TNF-alpha challenge. Attenuation of hepatic CCL-2 production with corticosteroids resulted in reduced monocyte levels after the TNF-alpha challenge. Thus, combined production of CC and CXC hepatic chemokines appears to amplify the central nervous system response to injury.

Animals↗
PubMed2004

Central Nervous System Lyme Disease.

Nervous system infection with Borrelia burgdorferi frequently causes meningitis and rarely causes encephalomyelitis. Altered cognitive function also can occur in the absence of central nervous system infection. Recently developed serodiagnostic tools, such as the C6 assay, and appropriate use of Western blotting, promise to improve diagnostic accuracy. Treatment trials have demonstrated the efficacy of relatively brief courses of oral antimicrobial agents, even in peripheral nervous system infection and meningitis. Several well-performed studies have clearly shown that prolonged antimicrobial treatment of "post-Lyme disease" is ineffective. Diagnosis and treatment of Lyme disease continue to improve.

Journal Article↗