https://pediatrics.med.ubc.ca/files/2012/05/paed_normal_ranges_Lancet_Series_201122985.pdf

Normal ranges of heart rate and respiratory rate in children from birth to 18 years of age: a systematic review of observational studies

Acetylcholine (ACh) has a crucial role in the peripheral and central nervous systems. The enzyme choline acetyltransferase (ChAT) is responsible for synthesizing ACh from acetyl-CoA and choline in the cytoplasm and the vesicular acetylcholine transporter (VAChT) uptakes the neurotransmitter into synaptic vesicles. Following depolarization, ACh undergoes exocytosis reaching the synaptic cleft, where it can bind its receptors, including muscarinic and nicotinic receptors. ACh present at the synaptic cleft is promptly hydrolyzed by the enzyme acetylcholinesterase (AChE), forming acetate and choline, which is recycled into the presynaptic nerve terminal by the high-affinity choline transporter (CHT1). Cholinergic neurons located in the basal forebrain, including the neurons that form the nucleus basalis of Meynert, are severely lost in Alzheimer's disease (AD). AD is the most ordinary cause of dementia affecting 25 million people worldwide. The hallmarks of the disease are the accumulation of neurofibrillary tangles and amyloid plaques. However, there is no real correlation between levels of cortical plaques and AD-related cognitive impairment. Nevertheless, synaptic loss is the principal correlate of disease progression and loss of cholinergic neurons contributes to memory and attention deficits. Thus, drugs that act on the cholinergic system represent a promising option to treat AD patients.

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Alzheimer's disease: Targeting the Cholinergic System

Phantom pain refers to pain in a body part that has been amputated or deafferented. It has often been viewed as a type of mental disorder or has been assumed to stem from pathological alterations in the region of the amputation stump. In the past decade, evidence has accumulated that phantom pain might be a phenomenon of the CNS that is related to plastic changes at several levels of the neuraxis and especially the cortex. Here, we discuss the evidence for putative pathophysiological mechanisms with an emphasis on central, and in particular cortical, changes. We cite both animal and human studies and derive suggestions for innovative interventions aimed at alleviating phantom pain.

Phantom limb pain: a case of maladaptive CNS plasticity?

The involvement of the basal ganglia in motor functions has been well studied. Recent neurophysiological, clinical and behavioral experiments indicate that the basal ganglia also process non-noxious and noxious somatosensory information. However, the functional significance of somatosensory information processing within the basal ganglia is not well understood. This review explores the role of the striatum, globus pallidus and substantia nigra in nociceptive sensorimotor integration and suggests several roles of these basal ganglia structures in nociception and pain. Electrophysiological experiments have detailed the non-nociceptive and nociceptive response properties of basal ganglia neurons. Most studies agree that some neurons within the basal ganglia encode stimulus intensity. However, these neurons do not appear to encode stimulus location since the receptive fields of these cells are large. Many basal ganglia neurons responsive to somatosensory stimulation are activated exclusively or differentially by noxious stimulation. Indirect techniques used to measure neuronal activity (i.e., positron emission tomography and 2-deoxyglucose methods) also indicate that the basal ganglia are activated differentially by noxious stimulation. Neuroanatomical experiments suggest several pathways by which nociceptive information may reach the basal ganglia. Neuroanatomical studies have also indicated that the basal ganglia are rich in many different neuroactive chemicals that may be involved in the modulation of nociceptive information. Microinjection of opiates, dopamine and gamma-aminobutyric acid (GABA) into the basal ganglia have varied effects on pain behavior. Administration of these neurochemicals into the basal ganglia affects supraspinal pain behaviors more consistently than spinal reflexive behaviors. The reduction of pain behavior following electrical stimulation of the substantia nigra and caudate nucleus provides additional evidence for a role of the basal ganglia in pain modulation. Some patients with basal ganglia disease (e.g., Parkinson's disease, Huntington's disease) have alterations in pain sensation in addition to motor abnormalities. Frequently, these patients have intermittent pain that is difficult to localize. Collectively, these data suggest that the basal ganglia may be involved in the (1) sensory-discriminative dimension of pain, (2) affective dimension of pain, (3) cognitive dimension of pain, (4) modulation of nociceptive information and (5) sensory gating of nociceptive information to higher motor areas. Further experiments that correlate neuronal discharge activity with stimulus intensity and escape behavior in operantly conditioned animals are necessary to fully understand how the basal ganglia are involved in nociceptive sensorimotor integration.

The role of the basal ganglia in nociception and pain

Sympathetic skin response (SSR), defined as the momentary change of the electrical potential of the skin, may be spontaneous or reflexively evoked by a variety of internal or by externally applied arousal stimuli. Although the suprasegmental structures influencing the SSR in humans are not well known, SSR has been proposed as a non-invasive approach to investigate the function of the sympathetic system. SSR is easy to apply but current procedures are not sufficiently reliable for diagnostic purposes, and show imperfect correlations both with clinical features and other measurements of autonomic, in particular, sudomotor dysfunction.

Sympathetic skin response: basic mechanisms and clinical applications.

A patient with hemiplegia and hemihypoesthesia is presented in whom preexisting phantom limb pain disappeared with the appearance of a stroke localized by CT scan to the posterior internal capsule. Differentiation between the cutaneous sensation and the sensation of phantom limb pain that appeared later seems to support the assumed existence of a polysynaptic sensory pathway that conveys the sensations of deafferentation.

Disappearance of phantom pain after focal brain infarction

SUMMARY. In a study of chronic lead intoxication in mature chickens, blood lead levels were significantly lower in hens than in roosters receiving the same oral dose of lead. It was then shown that eggshells from lead-treated hens contained 6-12 times the lead concentration of eggshells from control hens. Similarly, the lead content of egg yolks from treated hens was significantly higher than yolks from controls. Lead-treated hens laid significantly more eggs during the period of observation of nearly 3 years because of the increased frequency of laying cycles, which was almost three times that of control hens. A further observation was histologic damage to the mature testes of the rooster. RESUMEN. Efecto de la intoxicaci6n cr6nica por plomo en aves adultas. En un modelo para la intoxicaci6n cronica por plomo en aves adultas, se encontr6 que los niveles sanguineos de plomo fueron significantemente menores en gallinas que en gallos que recibieron la misma dosis oral de plomo. Subsecuentemente se demostro que las cascaras de los huevos procedentes de las gallinas tratadas con plomo contenian de 6 a 12 veces la concentraci6n encontrada en los huevos de las aves controles. Asi mismo, el contenido de plomo en las yemas de los huevos de las gallinas tratadas fue significantemente mayor que en los controles. Las gallinas tratadas con plomo pusieron un numero significantemente mayor de huevos durante el periodo de observaci6n de casi tres afios debido al aumento en la frecuencia de los ciclos de postura que fue casi tres veces que el de las gallinas controles. Una observaci6n adicional fue el daiio histol6gico en los testiculos de los gallos adultos.

The effect of chronic lead intoxication in mature chickens.

— The results of evaluation of the autonomic nervous system of a patient with amyotrophic lateral sclerosis are presented As previously reported, parasympathetic function and sympathetic adrenergic function were normal as assessed by cardiovascular reflexes However, a disturbance in sympathetic cholinergic function as measured by the sympathetic skin response was demonstrated We suggest that the latter test be included in all electrophysiological evaluations of autonomic function in amyotrophic lateral sclerosis

Sympathetic cholinergic dysfunction in amyotrophic lateral sclerosis

Objective: To study the neurocardiologic reflexes in young persons who have fainted under conditions of emotional stress. Design: Case-control study. Setting: Clinical neurophysiology laboratory in...

Barron Sa

Papers

Disappearance of phantom pain after focal brain infarction

The effect of chronic lead intoxication in mature chickens.

Sympathetic cholinergic dysfunction in amyotrophic lateral sclerosis

Vagal Cardiovascular Reflexes in Young Persons with Syncope

The effects of long-term lead intoxication on the nervous system of the chicken.