Biomedical subjects

Valter Tucci

Publications and source records attributed to Valter Tucci.

5 recordsLinked to original sources

PubMed2006

Cognitive aging in zebrafish.

BACKGROUND: Age-related impairments in cognitive functions represent a growing clinical and social issue. Genetic and behavioral characterization of animal models can provide critical information on the intrinsic and environmental factors that determine the deterioration or preservation of cognitive abilities throughout life. METHODOLOGY/PRINCIPAL FINDINGS: Behavior of wild-type, mutant and gamma-irradiated zebrafish (Danio rerio) was documented using image-analysis technique. Conditioned responses to spatial, visual and temporal cues were investigated in young, middle-aged and old animals. The results demonstrate that zebrafish aging is associated with changes in cognitive responses to emotionally positive and negative experiences, reduced generalization of adaptive associations, increased stereotypic and reduced exploratory behavior and altered temporal entrainment. Genetic upregulation of cholinergic transmission attenuates cognitive decline in middle-aged achesb55/+ mutants, compared to wild-type siblings. In contrast, the genotoxic stress of gamma-irradiation accelerates the onset of cognitive impairment in young zebrafish. CONCLUSIONS/SIGNIFICANCE: These findings would allow the use of powerful molecular biological resources accumulated in the zebrafish field to address the mechanisms of cognitive senescence, and promote the search for therapeutic strategies which may attenuate age-related cognitive decline.

Acetylcholinesterase↗

PubMed2006

Gene-environment interactions differentially affect mouse strain behavioral parameters.

Systematic phenotyping of mouse strains and mutants generated through genome-wide mutagenesis programs promises to deliver a wealth of functional genetic information. To this end, the appropriation of a standard series of phenotyping protocols is desirable to produce data sets that are consistent within and across laboratories and across time. Standard phenotyping protocols such as EMPReSS (European Mouse Phenotyping Resource for Standardised Screens) provide a series of protocols aimed at phenotyping multiple body systems that could realistically be adopted and/or reproduced in any laboratory. This includes a series of neurologic and behavioral screens, bearing in mind that this class of phenotype is well represented in targeted mutants and mutagenesis screens. Having cross-validated screening batteries in a number of laboratories and in a number of commonly used inbred strains, our group was interested in establishing whether subtle changes in cage environment could affect behavioral test outcome. Aside from unavoidable quantitative differences in test outcome, we identified significant and distinct genotype-environment-test interactions. For example, specific strain order in open-field center entries and total distance traveled can be reversed depending on the form of enrichment used, while prepulse inhibition of the acoustic startle response is, even quantitatively, unaffected by the enrichment condition. Our findings argue that unless systematically recorded, behavioral studies conducted under subtle variations in cage environment may lead to data misinterpretation, although this could be limited to particular behaviors. Further investigations into the extent and limits of genetic and environmental variables are critical for the realization of both behavioral and functional genomics endpoints.

Animals↗

PubMed2006

A comparison of physiological and behavioural parameters in C57BL/6J mice undergoing food or water restriction regimes.

Laboratory animals, when subjected to behavioural tests, are often motivationally primed by a period of prior water or food restriction. To date, it is still debatable which restriction protocol (water versus food) is more appropriate for different species. In general, a protocol is considered appropriate if animal discomfort is kept to a minimum whilst motivation for the task is maximised. Here we present a comparison study of the effects of water versus food restriction protocols in mice. The characterisation of the physiological and behavioural effects of food and water restriction in mice is beneficial for both institutional animal care centres and the scientific community. We have investigated body weight fluctuations in three groups of C57BL/6J female mice (water-restricted, food-restricted and control) in two different protocols (20 h versus 22 h of restriction per day) over 2 consecutive weeks. Subsequently, a selected number of mice from each group were subjected to a battery of behavioural tests to investigate exploratory, emotional and dominance behaviours, in addition to learning and memory processes. Body weight fluctuations suggested that mice tolerate a water restriction regimen better than a comparable food restriction regimen. Furthermore, behavioural performances demonstrated that food-restricted mice show a reduction in the exploration of a new environment and particular aspects of their timing memories are distorted. Finally, both water- and food-restricted mice tended to be more offensive than control mice when paired with an opponent in a social dominance test condition.

Adaptation, Physiological↗

PubMed2003

Emotional information processing in patients with narcolepsy: a psychophysiologic investigation.

OBJECTIVES: Cataplexy is the key symptom of the narcoleptic syndrome. It is usually triggered by emotions, which play an important role in the manifestation and severity of the disease. Accordingly, we compared the psychophysiologic effects on patients with narcolepsy and healthy subjects of processing visual stimuli that have established emotional valences. METHOD: Eight drug-free patients with narcolepsy with severe cataplexy and 8 controls were studied. Fifty-four color pictures (pleasant, neutral, and unpleasant) selected from the International Affective Picture System were presented on a monitor to the subjects. The effects of exposure to the pictures were assessed in muscular (corrugator, zygomatic and mylohyoid electromyographic activity), autonomic (blood pressure, heart rate, and skin conductance responses) cognitive (scalp-recorded event-related potentials), and subjective (valence, arousal, and dominance by Self-Assessment Manikin) systems. RESULTS: The autonomic, muscular, and cognitive systems showed an attenuated reaction to visual stimuli in patients compared to controls. Furthermore, patients with narcolepsy showed the lowest responses when unpleasant pictures were presented. CONCLUSIONS: Our data suggest that, compared to the group of healthy subjects, patients with narcolepsy suffer from a temporal disadvantage in input processing, in particular, of unpleasant stimuli. The drawback exhibited by these patients suggests reduced reactivity of the aversive motivational system responsible for negative or unpleasant emotions.

Adult↗

PubMed2003

Melatonin, Circadian Rhythms, and Sleep.

Experimental data show a close relationship among melatonin, circadian rhythms, and sleep. Low-dose melatonin treatment, increasing circulating melatonin levels to those normally observed at night, promotes sleep onset and sleep maintenance without changing sleep architecture. Melatonin treatment can also advance or delay the phase of the circadian clock if administered in the evening or in the morning, respectively. If used in physiologic doses and at appropriate times, melatonin can be helpful for those suffering from insomnia or circadian rhythm disorders. This may be especially beneficial for individuals with low melatonin production, which is established by measuring individual blood or saliva melatonin levels. However, high melatonin doses (over 0.3 mg) may cause side effects and disrupt the delicate mechanism of the circadian system, dissociating mutually dependent circadian body rhythms. A misleading labeling of the hormone melatonin as a "food supplement" and lack of quality control over melatonin preparations on the market continue to be of serious concern.

Journal Article↗