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Conditioning Procedure (conditioning + procedure)
Selected AbstractsAmperometric Ion Sensing Using Polypyrrole MembranesELECTROANALYSIS, Issue 5-6 2003Agata Michalska Abstract Oxidation/reduction of conducting polymers, coupled with ion exchange between the polymer and electrolyte solution can be utilized for amperometric ion sensing. Electrochemically deposited "model" polypyrrole membranes doped by chloride (PPyCl) and hexacyanoferrate (PPyFeCN) anions were studied from the point of view of their advantages and limits for amperometric determination of electroinactive anions and cations, respectively. Monotonous dependences of the current on electrolyte concentration were obtained for short reading times after potential step application (in the range of ms). The experimental conditions were optimized to obtain linear dependences: log (current) vs. log (KCl concentration) within the range 10,6,1,M. The advantages of the amperometric method over the potentiometric one are highlighted: much lower effect of redox and pH interferences, wider concentration range, elimination of long conditioning procedure. [source] Effect of auditory cortex lesions on the discrimination of frequency-modulated tones in ratsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 6 2006Natalia Rybalko Abstract The lateralization of functions to individual hemispheres of the mammalian brain remains, with the exception of the human brain, unresolved. The aim of this work was to investigate the ability to discriminate between falling and rising frequency-modulated (FM) stimuli in rats with unilateral or bilateral lesions of the auditory cortex (AC). Using an avoidance conditioning procedure, thirsty rats were trained to drink in the presence of a rising FM tone and to stop drinking when a falling FM tone was presented. Rats with a lesion of the AC were able to learn to discriminate between rising and falling FM tones; however, they performed significantly worse than did control rats. A greater deficit in the ability to discriminate the direction of frequency modulation was observed in rats with a right or bilateral AC lesion. The discrimination performance (DP) in these rats was significantly worse than the DP in rats with a left AC lesion. Animals with a right or bilateral AC lesion improved their DP mainly by recognizing the pitch at the beginning of the stimuli. The lesioning of the AC in trained animals caused a significant decrease in DP, down to chance levels. Retraining resulted in a significant increase in DP in rats with a left AC lesion; animals with a right lesion improved only slightly. The results demonstrate a hemispheric asymmetry of the rat AC in the recognition of FM stimuli and indicate the dominance of the right AC in the discrimination of the direction of frequency modulation. [source] Evidence for episodic memory in a pavlovian conditioning procedure in ratsHIPPOCAMPUS, Issue 12 2007Jamus O'Brien Abstract In an effort to evaluate episodic memory processes in the rat, we developed a novel Pavlovian conditioning procedure. Rats explored two distinctive contexts, one in the morning and the other in the evening. Subsequently, either in the morning or the evening, they received a foot shock immediately upon entry into a third context that equally resembled the two explored contexts. When conditioned freezing was measured at an intermediate time of day, rats showed significantly more fear of the context congruent with the time of day of the foot shock. Thus, rats automatically form an integrated time,place memory that can be flexibly updated by future events, essential characteristics of episodic memory. © 2007 Wiley-Liss, Inc. [source] Decreased Sensitivity to Ethanol Reward in Adolescent Mice as Measured by Conditioned Place PreferenceALCOHOLISM, Issue 7 2009Shelly D. Dickinson Background:, Many preclinical studies have demonstrated age-related differential sensitivity to various effects of ethanol between adolescent and adult animals. However, published data addressing possible differences in ethanol's motivational effects are sparse, particularly in mice. The present study examined age-related differences in the conditioned rewarding effects of ethanol in DBA/2J mice. Methods:, In the first experiment an unbiased place conditioning procedure was used to determine the rewarding effects of 2 g/kg ethanol in adult and adolescent DBA/2J mice. In a subsequent place conditioning experiment, the effects of 2 and 4 g/kg were assessed in adolescent mice. Results:, Adolescents demonstrated a place preference with the high dose of 4 g/kg but not with a more moderate dose of 2 g/kg. In contrast, 2 g/kg was sufficient to produce place preference in adult mice. Conclusions:, Adolescents are less sensitive than adults to the rewarding effects of ethanol but can experience reward with high doses. These results extend the current literature on ethanol's effects in adolescent animals. [source] A Mouse Model of Prenatal Ethanol Exposure Using a Voluntary Drinking ParadigmALCOHOLISM, Issue 12 2003Andrea M. Allan Background: The incidence of fetal alcohol spectrum disorders is estimated to be as high as 1 in 100 births. Efforts to better understand the basis of prenatal ethanol-induced impairments in brain functioning, and the mechanisms by which ethanol produces these defects, will rely on the use of animal models of fetal alcohol exposure (FAE). Methods: Using a saccharin-sweetened alcohol solution, we developed a free-choice, moderate alcohol access model of prenatal alcohol exposure. Stable drinking of a saccharin solution (0.066%) was established in female mice. Ethanol then was added to the saccharin in increasing concentrations (2%, 5%, 10% w/v) every 2 days. Water was always available, and mice consumed standard pellet chow. Control mice drank saccharin solution without ethanol. After a stable baseline of ethanol consumption (14 g/kg/day) was obtained, females were impregnated. Ethanol consumption continued throughout pregnancy and then was decreased to 0% in a step-wise fashion over a period of 6 days after pups were delivered. Characterization of the model included measurements of maternal drinking patterns, blood alcohol levels, food consumption, litter size, pup weight, pup retrieval times for the dams, and effects of FAE on performance in fear-conditioned learning and novelty exploration. Results: Maternal food consumption, maternal care, and litter size and number were all found to be similar for the alcohol-exposed and saccharin control animals. FAE did not alter locomotor activity in an open field but did increase the time spent inspecting a novel object introduced into the open field. FAE mice displayed reduced contextual fear when trained using a delay fear conditioning procedure. Conclusions: The mouse model should be a useful tool in testing hypotheses about the neural mechanisms underlying the learning deficits present in fetal alcohol spectrum disorders. Moreover, a mouse prenatal ethanol model should increase the opportunity to use the power of genetically defined and genetically altered mouse populations. [source] Sex differences in negative affective response during nicotine withdrawalPSYCHOPHYSIOLOGY, Issue 4 2006Joanne M. Hogle Abstract This study examined physiological indicants of the neurobiological mediators of negative affect during acute nicotine withdrawal. Eighty subjects (41 male) were assigned to one of four groups (24-h deprived or nondeprived dependent smokers, occasional smokers, and nonsmokers) and participated in an instructed fear conditioning paradigm involving cued administration of electric shock. Negative affective response was measured with fear-potentiated startle during cues that signaled electric shock and during the postcue offset recovery period. Salivary cortisol and self-report measures were also collected. Fear-potentiated startle results indicated that affective recovery postcue offset was delayed in nicotine-deprived women. Nicotine-deprived women also displayed elevated cortisol levels throughout the fear conditioning procedure. [source] Eyeblink conditioning anomalies in bipolar disorder suggest cerebellar dysfunctionBIPOLAR DISORDERS, Issue 1 2009Amanda R Bolbecker Objectives:, Accumulating research implicates the cerebellum in non-motor psychological processes and psychiatric diseases, including bipolar disorder (BD). Despite recent evidence that cerebellar lesions have been documented to trigger bipolar-like symptoms, few studies have directly examined the functional integrity of the cerebellum in those afflicted with BD. Methods:, Using a single-cue delay eyeblink conditioning procedure, the functional integrity of the cerebellum was examined in 28 individuals with BD (9 manic, 8 mixed, and 11 euthymic) and 28 age-matched healthy controls. Results:, Analysis of the bipolar group as a whole indicated a conditioned response acquisition and timing deficit compared to controls. However, when the bipolar group was categorized according to mood state (mixed, manic, euthymic), individuals tested during mixed episodes were strikingly impaired, performing significantly worse than all other groups on both the acquisition and timing of conditioned responses. Conclusions:, These findings extend prior research implicating cerebellar functional abnormalities in BD and suggest that cerebellar dysfunction may be associated with mood state and course of illness. [source] Classical conditioning in the rat fetus: Temporal characteristics and behavioral correlates of the conditioned responseDEVELOPMENTAL PSYCHOBIOLOGY, Issue 2 2002William P. Smotherman Abstract This study examined the temporal characteristics and behavioral correlates of the conditioned response (CR) following classical conditioning of the embryonic Day 20 (E20 rat fetus). The conditioning procedure involved pairing of an artificial nipple (the CS) with an infusion of milk (the US) to establish classical conditioning. The test for classical conditioning involved measurement of a stimulus-evoked facial wiping response in a classical conditioning test. Experiment 1 compared the effectiveness of one- and three-trial procedures to establish classical conditioning. Experiment 2, 3, and 4 described the time course for the CR following one- and three-trial conditioning procedures. Experiments 3b and 4b describe the behavioral responses to (a) presentation of the CS at the time of conditioning, (b) infusion of the milk US at the time of conditioning, and (c) reexposure to the CS before the test for classical conditioning. Experiments 5 and 6 exposed the fetus to manipulations that either increased or decreased stretching (a behavior found to be associated with the CR). The results are discussed in terms of the temporal characteristics and behavioral correlates of conditioned and unconditioned responses and their mediation by activity in endogenous mu and kappa opioid systems. © 2002 Wiley Periodicals, Inc. Dev Psychobiol 40: 116,130, 2002. DOI 10.1002/dev.10017 [source] Is coronally positioned flap procedure adjunct with enamel matrix derivative or root conditioning a relevant predictor for achieving root coverage?JOURNAL OF PERIODONTAL RESEARCH, Issue 5 2007A systemic review Background and Objective:, This study is a systemic review of coronally positioned flap, coronally positioned flap + chemical root surface conditioning, or coronally positioned flap + enamel matrix derivative (EMD) for the treatment of Miller class I and II gingival recession. Material and Methods:, All studies available through the Medline database by the end of October 2005 were used. Each study provided mean clinical attachment level, keratinized tissue, probing pocket depth, gingival recession depth and root coverage percentage before and after treatment with coronally positioned flap alone, coronally positioned flap + chemical root surface conditioning , or coronally positioned flap + EMD. Effectiveness was evaluated by comparing the weighted mean average in gingival recession depth, probing pocket depth, clinical attachment level, keratinized tissue and root coverage percentage achieved with the three treatments. Results:, Seven studies for the coronally positioned flap + EMD group, four studies for the coronally positioned flap + chemical root surface conditioning group, and seven studies for the coronally positioned flap group were retrieved for this weighted mean analysis. The results of clinical attachment level, gingival recession depth, and root coverage percentage in the coronally positioned flap + EMD group were statistically significantly better than the changes in the coronally positioned flap and coronally positioned flap + chemical root surface conditioning group at 6 and 12 mo (p < 0.001). There was no significant difference at the 6-mo comparison among clinical attachment level, keratinized tissue, probing pocket depth, and gingival recession depth, except in the root coverage percentage for coronally positioned flap and coronally positioned flap + chemical root surface conditioning groups. Conclusion:, The results suggest that root coverage by the coronally positioned flap and coronally positioned flap + chemical root surface conditioning procedures were unpredictable but became more predictable when the coronally positioned flap procedure was improved by the modification of adding EMD. [source] | |||||||||||||