Neuron brain and

The three most important parts of the brain are the cerebrum, brainstem, and cerebellum. They are covered by several membranes. Between the skull and the brain, there are three membranes (meninges) dura mater (two layers), arachnoid (resembling a spider s web), and pia mater. The pia mater is in direct contact with the cortex, and between the pia mater and the arachnoid there is space for the highly conductive cerebrospinal fluid (CSF). 

The brainstem is a prolongation of the spinal cord and is the eldest part of the brain, taking care of basic functions necessary in all vertebrates. 

The cerebellum is a motion computer optimized for rapid movement control in animals and humans. 

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The toxicity of C60 has been found to be related to its ability to cause oxidative stress (Oberdorster, 2004 and Sayes et al., 2005, 2007). However, literature describing the toxicity of C60 is contradictoiy. The first report on C60 cytotoxicity originated from Tsuchiya et al. who found that C60 inhibited cell proliferation and differentiation dose-dependently in mouse midbrain cells treated at -400 pg/ml for six days. Tsuchiya et al. proposed that reactive oxygen species (ROS) contributed to C60 cytotoxicity. The ROS generation and embryo head abnormalities suggested that C60 may contribute to brain and neuronal diseases such as Down syndrome, Alzheimer s, and Parkinson s disease (Tsuchaiya, 1996). The research that... 

High enzyme activity found in immature rat brain and neuronal cultures (Ghersi-Egea et al.,... 

High NADPH cytochrome P450 reductase activity is found in immature rat brain and neuronal cultures, but very little cytochrome P450, thus NADPH cytochrome P450 reductase may be involved in cytochrome P450 independent pathways (Ghersi-Egea et al., 1993). 

Originally, it was assumed that while the CBi receptor is found primarily in the brain and neuronal tissue, while the CB2 receptor is found exclusively outside the central nervous system, primarily in immune tissue. However, Van Sickle etal. reported the expression of CB2 receptor mRNA and protein localization on brainstem neurons. Recently, it was demonstrated that CB2 receptor and their gene transcripts are also distributed in the mammalian brain. The levels of CB2 receptors in brain are... 

Nitric oxide and carbon monoxide. The gaseous molecules NO and CO have both been found in the brain, and neuronal NO synthase (nNOS or NOS I) has been studied intensively.844-847 NO synthases and the functions of NO and CO are discussed in Section A7 and in Chapter 18. Complexity in understanding the role of NO in the brain arises from the fact that different isoenzyme forms of NO synthase occur in three different types of cell nNOS in neurons, iNOS from microglial immune system cells, and eNOS from endothelial cells of capillary blood vessels.846 All three types of cells are so tightly intermingled in the brain that it is hard to interpret observed experimental... 

Neurobiology is the study of brain and neuronal functioning usually emphasizing normal brain functioning in experimental animals rather than man. True or False. 

Minakami R, lida K, Hirakawa N, Sugiyama H (1995) The expression of two splice variants of metabotropic glutamate receptor subtype 5 in the rat brain and neuronal cells during development. J Neurochem 65 1536-1542. 

Tay-Sachs disease A genetic disease that is a result of a deficiency in hexosaminidase A (P-A-acetylhexosaminidase), an enzyme that is involved in the degradation of ganghosides in the lysosome. The disease is prevalent in Jewish children of Eastern European descent and leads to a buildup of ganghoside in nerve cells of the brain and neuronal dysfunchon. 

To study the incorporation of choline into PC of neurons and glial cells, animals were injected as described for the in vivo experiments. The cerebral cortex was carefully dissected out from the excised brains and neuronal and glial enriched fractions were obtained following the procedure described by Freysz et al. (1969). Lipids were extracted from the isolated cell suspensions and radioactivity measured as described above. 

The chemistry of the brain and central nervous system is affected by a group of substances called neurotransmitters, substances that carry messages across a synapse from one neuron to another Several of these neurotransmitters arise from l tyrosine by structural modification and decarboxylation as outlined m Figure 27 5... 

Dopamine. Dopamine (DA) (2) is an intermediate in the synthesis of NE and Epi from tyrosine. DA is localized to the basal ganglia of the brain and is involved in the regulation of motor activity and pituitary hormone release. The actions of DA are terminated by conversion to dihydroxyphenylacetic acid (DOPAC) by monoamine oxidase-A and -B (MAO-A and -B) in the neuron following reuptake, or conversion to homovanillic acid (HVA) through the sequential actions of catechol-0-methyl transferase (COMT) and MAO-A and -B in the synaptic cleft. 

Neuronal Norepinephrine Depleting Agents. Reserpine (Table 6) is the most active alkaloid derived from Rauwolfia serpentina. The principal antihypertensive mechanism of action primarily results from depletion of norepinephrine from peripheral sympathetic nerves and the brain adrenergic neurons. The result is a drastic decrease in the amount of norepinephrine released from these neurons, leading to decrease in vascular tone and lowering of blood pressure. Reserpine also depletes other transmitters including epinephrine, serotonin [50-67-9] dopamine [51-61-6] ... 

In addition, adenosine is implicated in sleep regulation. During periods of extended wakefulness, extracellular adenosine levels rise as a result of metabolic activity in the brain, and this increase promotes sleepiness. During sleep, adenosine levels fall. Caffeine promotes wakefulness by blocking the interaction of extracellular adenosine with its neuronal receptors. ... 

According to the amyloid hypothesis, the A 3 peptide plays a critical role in the pathogenesis of Alzheimer s disease [1]. Major forms of A 3 produced encompass 38, 40 or 42 residues. A 342 is more prone to aggregation than A 340 and in animal models an increased A[342/ A (340 ratio results in amyloid plaque pathology even when total A 3 levels are reduced [4]. The generation of A 3 is a normal process and A 3 is present in the brains and body fluids of humans throughout life. Neuronal... 

The first hormonal signal found to comply with the characteristics of both a satiety and an adiposity signal was insulin [1]. Insulin levels reflect substrate (carbohydrate) intake and stores, as they rise with blood glucose levels and fall with starvation. In addition, they may reflect the size of adipose stores, because a fatter person secretes more insulin than a lean individual in response to a given increase of blood glucose. This increased insulin secretion in obesity can be explained by the reduced insulin sensitivity of liver, muscle, and adipose tissue. Insulin is known to enter the brain, and direct administration of insulin to the brain reduces food intake. The adipostatic role of insulin is supported by the observation that mutant mice lacking the neuronal insulin receptor (NDRKO mice) develop obesity. 

Although mast cells and basophils probably account for >90% of stored histamine in the body, histamine is also present in platelets, enterochromaffin-like cells, endothelial cells, and neurons. Histamine can act as a neurotransmitter in the brain. Histaminergic nerves have their cell bodies within a very small area of the brain (the magnocellular nuclei of the posterior hypothalamus) but have axons in most areas of the forebrain. There is also evidence for axons projecting into the spinal (Fig. 1) cord. Finally, there is evidence that histamine synthesis can be induced in tissues undergoing rapid tissue growth and repair. In certain neonatal tissues (e.g. liver), the rate of synthesis of this unstored diffusable histamine (termed nascent histamine) is profound and may point to a role for histamine is cell proliferation. 

Hi-receptors in the adrenal medulla stimulates the release of the two catecholamines noradrenaline and adrenaline as well as enkephalins. In the heart, histamine produces negative inotropic effects via Hr receptor stimulation, but these are normally masked by the positive effects of H2-receptor stimulation on heart rate and force of contraction. Histamine Hi-receptors are widely distributed in human brain and highest densities are found in neocortex, hippocampus, nucleus accumbens, thalamus and posterior hypothalamus where they predominantly excite neuronal activity. Histamine Hrreceptor stimulation can also activate peripheral sensory nerve endings leading to itching and a surrounding vasodilatation ( flare ) due to an axonal reflex and the consequent release of peptide neurotransmitters from collateral nerve endings. 

The locus ceruleus is a structure located on the floor of the fourth ventricle in the rostral pons. It contains more than 50% of all noradrenergic neurons in the brain, and projects to almost all areas of the central nervous system. 

Very low-density lipoprotein receptor ( VLDLR) and APOE receptor-2 ( APOER2) are two gene family members with redundant functions. They are expressed in neurons of the developing brain and act as cell... 

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