Rotational behavior

Finnegan, K. Kanner, M. and Meltzer, H.Y. Phencyclidine-induced rotational behavior in rats with nigrostriata 1 lesions and its modulation by dopaminergic and cholinergic agents. Pharmacol Biochem Behav 5 651-660, 1976. 

Heikkila, R.E., Cabbat, F.S., and Duviosin, R.C., Motor activity and rotational behavior after analogs of cocaine correlation with dopamine uptake blockade, Commun. Psychopharm., 3, 285, 1979. 

Ungerstedt, U., Striatal dopamine release after amphetamine or nerve degeneration revealed by rotational behavior, Acta Physiol. Scand, 367, 49, 1971. 

The extent of receptor supersensitivity after unilateral nigrostriatal lesions can be quantified by measuring the extent of rotational behavior. After selective nigrostriatal lesions have been produced in rats by injections of 6-hydroxydopamine into the substantia nigra, the number of dopamine receptors in the ipsilateral corpus striatum increases markedly, and the increase in the number of receptors may correlate with the extent of behavioral supersensitivity as monitored by rotational behavior [52]. Thus, the increase in receptor density appears to play a role in the behavioral supersensitivity of these animals. 

The rotational mobility of human low-density (LDL) and very-low-density (VLDL) lipoproteins was studied as a function of viscosity and temperature in the range of —90 to — 50°C.(86)The rotational behavior for LDL is represented by a single correlation time, consistent with the overall rotation of a spherical rigid particle as the source of the phosphorescence depolarization. For VLDL, internal peptide motions dominate the depolarization profile. 

Because the partition function ratio / is defined in such a way that the classical rotational and translational contributions are canceled, equations 11.40, 11.41 and 11.43 must be modified by introducing the ratio of the deviations from classical rotational behavior of heavy and light hydrogen molecules. For small values of [Pg.779]

The determination of fluorescence parameters of peptides requires the presence of either natural fluorescent amino acid residues (intrinsic fluorescence) or of extrinsic fluorescent probes covalently attached to the peptide at appropriate sites. The use of extrinsic fluorescent probes is mandatory in cases where the conformational or rotational behavior of a peptide is examined in the presence of proteins that contain intrinsic fluorescent amino acids. 

Steady-state fluorescence polarization studies have been carried out with a number of peptides, including model peptides, ACTH, glucagon, melittin, and thyrocalcitonin. This work has been reviewed 5 and will not be discussed in the present article. More recently, interesting information on the rotational behavior and structural flexibility of various peptides has been obtained from fluorescence anisotropy decay measurements. 

Energy transmitted over the drive shaft induces the release of newly synthesized ATP on one of the /3-subunits, simultaneously promotes ATP synthesis on the next /3-subunit and coneomitantly binds ADP, Mg + and Pi to the third . It is suspected that ADP is bound before Pj . A binding-change mechanism is often used to illustrate this rotational behavior. One of the three /3-subunits is believed to be in an open O conformation. Upon rotation, this changes to a loose L conformation with a high binding affinity for ADP and Pj. After these substrates are bound, rotation results in a tightly closed conformation T in which ATP is synthesized. Further rotation opens the conformation (now O) and ATP is released . Upon a rotation of 360°, each /3-subunit has successively bound ADP and Pi, synthesized ATP and released it. 

Model building in the computer is used to compare the influence of remote contacts on the stereochemistry and properties of P-1,2-, p-1,3-, and P-1,4-glucans, including their optical rotation behavior, and to explore the possibility of chain folding in cellulose, chltin, and xylan derivatives. 

Addition of galactomannan to agarose-water systems profoundly alters the optical rotation behavior. Thus, both in the absence and presence of locust-bean gum, there is, below 35°, a sharp shift in optical rotation. However, these shifts are opposite in sign, as shown in Fig. 6. The reheating curves also differ, in that, when locust-bean gum is present, a butterfly-shaped hysteresis curve is obtained.40... 

A stereotyped compulsive behavior is induced both in humans and in laboratory animals by amphetamines. This provided the basis for a method that has been used to measure the action of drugs on amphetamine-sensitive centers of the brain. A lesion in the nigrostriatal bundle on one side of a rat brain was made by injection of a neurotoxic compound such as 6-hydroxydopamine. This caused degeneration of dopamine-containing neurons on one side of the brain. When rats that had been injured in this way were given amphetamines, they developed a compulsive rotational behavior. Administration of chlorpromazine and several other antipsychotic drugs neutralized this behavior and in direct proportion to the efficacy in clinical use, an observation that also supports the theory that schizophrenia involves overactivity of dopamine neurons. 

Ungerstedt U, Arbuthnott GW (1970) Quantitative recording of rotational behavior in rats after 6-hydroxy-dopamine lesions of the nigrostriatal dopamine system. Brain Res 24 485-493. 

YurekDM (1997) Intranigral Transplants of Fetal Ventral Mesencephalic Tissue Attenuate Dl-Agonist-Induced Rotational Behavior. Exp Neurol 143 1-9. 

Fedrowitz M, Potschka H, Richter A, Loscher W (2000) A microdialysis study of striatal dopamine release in the circling rat, a genetic animal model with spontaneous lateralized rotational behavior. Neuroscience 97 69-77. 

Heikkila RE, Shapiro BS, Duvoisin RC (1981) The relationship between loss of dopamine nerve terminals, striatal [3H]spiroperidol binding and rotational behavior in unilaterally 6-hydroxydopamine-lesioned rats. Brain Res 211 285—292. 

Richter A, Ebert U, Nobrega JN, Vallbacka JJ, Fedrowitz M, Loscher W (1999) Immunohistochemical and neurochemical studies on nigral and striatal functions in the circling (ci) rat, a genetic animal model with spontaneous rotational behavior. Neuroscience 59 461-471. 

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