Models enteric nervous system

Primary and secondary sensory neurons of the enteric nervous system A model of primary and secondary afferents with a fast sodium current, an N-type calcium current, a delayed rectifier potassium current. 

Doodnath R, Dervan A, Wride MA et al (2010) Zebrafish an exciting model for investigating the spatio-temporal pattern of enteric nervous system development. Pediatr Slug Int 26 1217-1221... 

Bard, F., Cannon, C., Barbour, R. et al. Peripherally administered antibodies against amyloid beta-peptide enter the central nervous system and reduce pathology in a mouse model of Alzheimer disease. Nature Med. 6 916-919,2000. 

During the early twentieth century the barbiturates were used in children and adolescents for their sedative and hypnotic effects however, their safety profile and propensity to cause physical dependence led scientists in search of safer anxiolytics. The development of animal models of behavioral disorders facilitated the formulation of drugs with more specific central nervous system (CNS) effects. In 1959, chlordiazepoxide (Librium) was the first benzodiazepine (BZ) to receive a patent. It entered the market in 1960, followed by diazepam (Valium) in 1963. Today, over 35 BZs have been formulated and over 10 are available in the United States (Ballenger, 1995 Hobbs et ah, 1996). 

A model for the action of cocaine and amphetamine at a dopaminergic synapse in the central nervous system. Cocaine (right side) blocks the dopamine reuptake transporter (DAT). Amphetamine (left side) has several effects. It enters the nerve ending via reverse transport by the DAT and displaces dopamine (DA) from vesicles by altering their pH. It also inhibits dopamine metabolism by MAO in the nerve ending. The increased intraneuronal dopamine causes reversal of the DAT and dopamine floods into the synapse. 

Bard, F., Cannon, C., Barbour, R., Burke, R. L., Games, D., Grajeda, H., Guido, T., Hu, K., Huang, J., Johnson-Wood, K., Khan, K., Kholodenko, D., et al. (2000). Peripherally administered antibodies against amyloid beta-peptide enter the central nervous system and reduce pathology in a mouse model of Alzheimer disease. Mat. Med. 6, 916-919. 

HSE occurs in a certain percentage of mice or rabbits following infecdon. The frequency of HSE in experimental infec dons is dependent on the pathogenic po ten dal of the HSV-1 and the mouse sd ain used for experimental infecdon. For HSE to occur after ocular infecdon, the virus must enter the TG, and then spread to the CNS, or the virus directly gains access into the brain via the opdc nerve. Models have also been developed in which the virus is directly inoculated into the brain. In this model, d ansport from the peripheral dssue the peripheral nervous system the CNS is not important. Thus, viral genes necessary for neuronal d ansport and spread are not crucial for virus infecdon if the brain is inoculated. 

Fig. 15. Hypothetical model of how initiators and modulators that affect insulin release may reach A-, B- and D-cells. The first target of arterial blood containing nutrients, hormones, peptides and drugs is the B-cell. From there, via an intraislet portal vein system, blood which now also contains released insulin flows to the mantle where A- and D-cells are localized and from there enters the circulation. Nerves derived from the autonomous nervous system which contain neurotransmitters (acetylcholine, noradrenaline) and neuropeptides (including vasoactive intestinal peptide (VIP), gastrin-releasing peptide (GRP), galanin) are connected to islet cells. Glucagon (A-cells) and somatostatin (D-cells) reach other endocrine cells in the islet in a paracrine manner. The B-cell may also be the target of previously released insulin via a short loop.

The shape and size of a molecule of a substance, together with the strength and polarity of its bonds, largely determine the properties of that substance. Some of the most dramatic examples of the important roles of molecular architecture are seen in biochemical reactions. For example, the chapter-opening photograph shows a molecular model of diazepam, better known as Valium. In the body, this relatively simple molecule enters into an extraordinary array of biochemical interactions. Valium works by binding to certain important sites in the central nervous system. Its... 

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