P Driscoll

Hôpitaux Universitaires de Genève, Genève, Geneva, Switzerland

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Publications (54)194.67 Total impact

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    ABSTRACT: Anxiety-related behaviors were evaluated across five tests in a sample of 277 rats from a genetically heterogeneous stock (N/Nih-HS rats), derived from an eight-way cross of inbred strains, and compared with the performance of RLA-I (high anxious) and RHA-I (low anxious) rats in the same tests. These tests either evoke unlearned (novel-cage activity (NACT), elevated "zero" maze (ZM), baseline acoustic startle response (BAS)) or learned (fear-potentiated startle (FPS), two-way active-shuttle box-avoidance acquisition (SHAV)) anxious/fearful responses. The results overall showed that unlearned anxiety responses/behaviors were predictive of behavior in learned fear (i.e. fear-potentiated startle) and conflict (i.e. two-way active avoidance acquisition) situations. Moreover, it was found that N/Nih-HS rats either resemble RLA-I rat anxiety/fear scores or fall in between those of the RLA-I (high anxious) and the RHA-I (low anxious) rat strains. An additional regression analysis (of N/Nih-HS rat data) showed significant positive influences of (unlearned) baseline startle response, risk assessment (i.e. stretch-attend) behavior and activity (5min) in a novel cage on SHAV acquisition, while baseline startle and entries into the open section of the elevated 'zero' maze test of anxiety were the main variables influencing FPS. This indicates that startle responses may have a facilitating role in the rat's active responses in the two-way active (shuttlebox) avoidance acquisition. The results of this behavioral evaluation of N/Nih-HS rats show that unconditioned anxiety (e.g. in the ZM test) predicts learned fear-related responses (e.g. FPS and SHAV) to some extent, while a positive association is also observed between BAS and SHAV. These findings are discussed in terms of their potential usefulness for present and future neurobehavioral and genetic studies of fearfulness/anxiety.
    Behavioural brain research 09/2009; 202(1):92-101. · 3.22 Impact Factor
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    ABSTRACT: Whereas many behavioral studies with rats have been traditionally concerned with tests and/or models attempting to deal with subjects such as anxiety, depression, hyperactivity, alcoholism and drug abuse, as they pertain to the human conditions, critical and integrated analyses of the vast amounts of information which have been accumulated, and an application of the same to the realm of personality traits, are long overdue. One such application, for example, might deal with the etiology of substance use and abuse toward which different animal models, considered together, can undoubtedly play a decisive role, especially as genetic factors are known to be extensively involved in the temperament differences underlying these phenomena in both rats and humans. The major contributions of such models toward this goal will, of course, pertain to unraveling the fundamental neurochemical processes involved and to deciphering their genetic origins.
    12/2008: pages 281-300;
  • Thierry Steimer, Peter Driscoll
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    ABSTRACT: Inter-individual differences in neuroendocrine and behavioural responses to environmental challenges will be considered within the context of psychogenetic selection, using the Roman High-(RHA) and Low-(RLA) Avoidance rat lines as an example. We assume that the selected genotypes, by interacting with environmental factors, determine specific 'biobehavioural profiles'. Practical and theoretical problems regarding the measurement of inter-individual vs line/strain differences, the definition of 'traits' vs experimental variables, and possible correlations between physiological and behavioural parameters will be discussed. We will argue that environmental influences are the main cause of inter-individual variability, and that the genotype only constitutes a 'blueprint' from which typical biobehavioural profiles are established, notably under the influence of early environmental factors. These biobehavioural profiles may correspond in part to human categories known as 'types', 'temperaments' or 'personality traits'. Within each category (including those which can be obtained by psychogenetic selection), more individual personality traits can evolve, notably as a result of social interactions and particular life events.
    Neuroscience & Biobehavioral Reviews 03/2005; 29(1):99-112. · 10.28 Impact Factor
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    ABSTRACT: The mesolimbic dopamine system is considered to play a pivotal role in the locomotor activation produced by psychostimulants and in the augmentation of this effect observed upon repeated drug administration, a process denominated behavioral sensitization. The selective breeding of Roman high- (RHA) and low-avoidance (RLA) rats, respectively, for rapid versus poor active avoidance acquisition has resulted in two phenotypes that differ in the functional properties of the mesolimbic dopamine system and in their behavioral and neurochemical responses to addictive drugs, including psychostimulants and opiates. Hence, the present study was designed to compare the ability of these lines to develop behavioral sensitization to psychostimulants. To this aim, the acute effects of amphetamine (0.125 or 0.25 mg/kg, s.c.) on locomotion were assessed in RHA and RLA rats prior to and subsequent to 10 daily doses of either amphetamine (1 mg/kg, s.c.) or saline (1 ml/kg, s.c.). In the RHA line, the locomotor activation produced by either challenge dose of amphetamine was more pronounced in rats that had been repeatedly treated with amphetamine versus the respective saline treated controls. In contrast, no significant change in locomotor activity was observed in RLA rats. Likewise, repeated amphetamine caused an increased frequency of sniffing, rearing, licking/gnawing, and grooming versus the control, repeated saline, group only in the RHA line. The results show that the repeated treatment regimen used in this study induced behavioral sensitization to amphetamine in RHA rats, but not in their RLA counterparts, and underscore the utility of these lines for studying the influence of neural substrates and genetic make up on the individual vulnerability to addiction.
    Behavioural Brain Research 03/2005; 157(1):147-56. · 3.33 Impact Factor
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    ABSTRACT: Addictive substances like morphine and psychostimulants induce a preferential increase in dopamine (DA) output in the nucleus accumbens (NAC), a major terminal field of the mesolimbic dopaminergic projection. Two subregions of the NAC, the dorsolateral core and the ventromedial shell, are thought to subserve different functions related to the reinforcing properties of natural and drug rewards. The selective breeding of Roman high- (RHA) and low-avoidance (RLA) rats, respectively, for rapid vs. extremely poor active avoidance acquisition in a shuttle-box has resulted in two phenotypes that differ in their behavioural and neurochemical responses to addictive drugs. We used brain dialysis to assess whether such differences in the responsiveness to drugs of abuse are related to differences in mesolimbic DA neuron function. In RHA rats, morphine, cocaine, and amphetamine caused a larger increase in DA efflux in the NAC shell vs. the NAC core, whereas the profile for the drug-induced increases in DA output was almost completely superimposable in the NAC shell and NAC core of RLA rats. Moreover, morphine, cocaine, and amphetamine caused a larger increment in basal DA output in the NAC shell of RHA rats vs. the NAC shell of RLA rats. These drugs also elicited a more robust increase in locomotion, rearing, sniffing, and grooming in RHA than in RLA rats. These results demonstrate that genetically determined differences in the functional properties of DA neurons projecting to the NAC shell may critically influence the behavioural response patterns to addictive drugs that distinguish the Roman lines.
    Neuropharmacology 05/2004; 46(5):688-99. · 4.11 Impact Factor
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    ABSTRACT: The selective breeding of Roman high- (RHA/Verh) and low-avoidance (RLA/Verh) rats for rapid versus poor acquisition of active avoidant behaviour has produced two behavioural phenotypes with different performances in a variety of animal models of anxiety, in which RLA/Verh rats are consistently more fearful than RHA/Verh rats. In addition, these two lines display different functional properties of brain neurotransmitters like serotonin (5-HT), known to be involved in the expression of anxiety- and depression-related behaviours. Therefore, we used brain microdialysis and [3H]-citalopram binding autoradiography to characterize further the neurochemical properties of 5-HTergic transmission in the two lines. No significant line-related differences were detected in the basal 5-HT output in the frontoparietal cortex (FPCx). In contrast, the increase in the cortical 5-HT output elicited by the systemic administration or the local application, via reverse dialysis, of chlorimipramine and fluoxetine was more robust in RHA/Verh than in RLA/Verh rats. Moreover, the binding signal of [3H]-citalopram to 5-HT re-uptake sites was more intense in the FPCx of RHA/Verh rats than in their RLA/Verh counterparts. These findings suggest that the functional tone of the 5-HTergic projection to the FPCx is stronger in the RHA/Verh line relative to the RLA/Verh line. It is proposed that RLA/Verh rats may be used as a model with heuristic value for studying the role of 5-HTergic transmission in anxiety and in the anxiolytic effects of monoamine re-uptake inhibitors.
    Journal of Neurochemistry 08/2003; 86(2):422-31. · 3.97 Impact Factor
  • Thierry Steimer, Peter Driscoll
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    ABSTRACT: The Swiss sublines of Roman high-(RHA/Verh) and low-(RLA/Verh) avoidance rats have been genetically selected for good vs. poor performance in two-way active avoidance since 1972. RLA/Verh rats show increased stress responses (e.g. freezing behaviour, ACTH, corticosterone and prolactin secretion) and adopt a more passive (or reactive) coping style when confronted with a novel environment. In the open field, elevated plus-maze, black/white box test, and in a new light/dark open field test, RLA/Verh rats appear to be more anxious than their RHA/Verh counterparts. Anxiety may result from their particular psychophysiological profile, i.e. increased emotionality combined with a passive coping style. In contrast, RHA/Verh rats are less responsive to stress, they show little anxiety in novel situations and tend to be impulsive and novelty (sensation) seekers. Some behavioural differences are already noticeable shortly after birth, but the full pattern appears to stabilize only after puberty. Gene-environment interactions are critical in establishing this pattern. The data reviewed indicate that the differences between RHA/Verh and RLA/Verh rats probably result from a complex interaction among divergent anxiety/emotionality characteristics, differences in locomotor activity and novelty/reward seeking, as well as active vs. passive coping styles. It is proposed further that these divergent personality types are to be found not only in other selective breeding programs but in the form of individual differences in most populations of rats used for this type of research.
    Stress 07/2003; 6(2):87-100. · 3.25 Impact Factor
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    ABSTRACT: The mesocortical and mesolimbic dopaminergic (DAergic) pathways are activated by either aversive or rewarding stimuli. The functional tone of these DAergic neurons also increases during the execution of cognitive tasks. The present study was designed to examine the relationship between mesocortical and mesolimbic DAergic function and the expression of fear-related behaviours as compared with attention- and cognition-related mechanisms (e.g. coping strategies), in response to aversive conditions. To this aim, we used two psychogenetically selected rat lines, Roman high-avoidance (RHA/Verh) and Roman low-avoidance (RLA/Verh), which display drastically different emotion- and coping-related behaviours in response to stressors: RLA/Verh rats are 'reactive copers' and more fearful than RHA/Verh rats, which are 'proactive copers'. Brain dialysis experiments demonstrated that tail-pinch (TP) and the anxiogenic compounds pentylenetetrazol (PTZ) and ZK 93426 increased DA output in the medial prefrontal cortex (PFCX) of RHA/Verh but not RLA/Verh, rats. In contrast, in the shell compartment of the nucleus accumbens (NAC shell), TP caused a small increase in DA output only in RLA/Verh rats, whereas PTZ and ZK 93426 had no significant effect on either line. RHA/Verh rats displayed more robust and longer lasting coping activity and less frequent freezing and self-grooming episodes than did RLA/Verh rats after TP, PTZ or ZK 93426. This dissociation between fear-related behaviour and cortical DAergic activation argues against the view that the latter may be involved in the control of fear-like responses. We therefore propose that the activation of mesocortical DAergic projections by aversive stimuli underlies the cognitive mechanisms that are triggered in an attempt to gain control over the stressor.
    European Journal of Neuroscience 07/2003; 17(12):2716-26. · 3.75 Impact Factor
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    ABSTRACT: The pattern of sex differences in a large sample (about 400 for each sex) of F2-generation rats, derived from inbred Roman high- and low-avoidance strains differing in fearfulness and brain functioning, was investigated. We obtained measures from responses to a battery of novel/threatening tests [open field (OF), plus maze (PM), hole board (HB), activity (A), and acoustic startle reflex (ASR)] as well as learned fear paradigms [classical fear conditioning (CFC) and shuttlebox avoidance conditioning (SAC)]. The results showed that almost all behaviors assessed fit with a pattern of unidirectional sex effects characterized by male rats as being more fearful than females: males defecated more than females in the OF, PM, HB, ASR, and CFC; ambulated less in the OF, PM, A, and SAC; showed more self-grooming in PM and HB; explored the open arms of the PM and the holes of the HB less; displayed enhanced ASR; and showed poorer performance in the SAC task. We applied two factor analyses to each sex showing that, in general, they shared a common three-factor structure: a Learned Fear Factor comprising SAC and CFC responding, a Fear of Heights/Open Spaces Factor with the highest loadings for open arm behavior in the PM, and an Emotional Reactivity Factor, mainly grouping defecations, ambulation, and self-grooming. These results indicate that the essential components of fearful behavior are similar for both sexes in an inbred but genetically heterogeneous population.
    Physiology & Behavior 05/2003; 78(4-5):723-32. · 3.16 Impact Factor
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    ABSTRACT: The Roman high- and low-avoidance (RHA/Verh and RLA/Verh) rat lines represent, respectively, low emotional/anxious and high novelty seeker vs. high emotional/anxious and low novelty seeker profiles. In the present study, RLA/Verh and RHA/Verh rats, either reared in pairs from weaning (untreated) or reared in groups of 8-10 in an enriched environment until the age of 7 months, were tested for exploratory and novelty-seeking behavior in the hole board (including novel objects under the holes), as well as for their preference for saccharin-water and ethanol-water in a two-bottle free-choice paradigm. Testing started when rats were 20 months old in order to study the long-lasting effects of differential rearing. RHA/Verh rats explored more and showed greater preference for (and intake of) saccharin as well as for ethanol than RLA/Verh rats, thus confirming their validity as a rat model for sensation/reward seeking. Environmental enrichment (EE) increased head-dipping behavior (i.e., novelty seeking) in both rat lines, without affecting locomotor activity. EE treatment increased the preference for, and volume intake of, saccharin (especially at the higher concentrations tested) in the relatively low saccharin-preferring RLA/Verh rats, and also enhanced ethanol consumption in both rat lines. Thus, the results demonstrate consistent and enduring effects of EE on incentive-seeking behavior and further the analysis of how individual differential predispositions for the need of novelty and contact with (or consumption of) rewarding substances arise through either biological (genetic) or early environmental factors, or both.
    Pharmacology Biochemistry and Behavior 09/2002; 73(1):225-31. · 2.82 Impact Factor
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    ABSTRACT: A critical test for a gene that influences susceptibility to fear in animals is that it should have a consistent pattern of effects across a broad range of conditioned and unconditioned models of anxiety. Despite many years of research, definitive evidence that genetic effects operate in this way is lacking. The limited behavioral test regimes so far used in genetic mapping experiments and the lack of suitable multivariate methodologies have made it impossible to determine whether the quantitative trait loci (QTL) detected to date specifically influence fear-related traits. Here we report the first multivariate analysis to explore the genetic architecture of rodent behavior in a battery of animal models of anxiety. We have mapped QTLs in an F2 intercross of two rat strains, the Roman high and low avoidance rats, that have been selectively bred for differential response to fear. Multivariate analyses show that one locus, on rat chromosome 5, influences behavior in different models of anxiety. The QTL influences two-way active avoidance, conditioned fear, elevated plus maze, and open field activity but not acoustic startle response or defecation in a novel environment. The direction of effects of the QTL alleles and a coincidence between the behavioral profiles of anxiolytic drug and genetic action are consistent with the QTL containing at least one gene with a pleiotropic action on fear responses. As the neural basis of fear is conserved across species, we suggest that the QTL may have relevance to trait anxiety in humans.
    Genome Research 05/2002; 12(4):618-26. · 14.40 Impact Factor
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    ABSTRACT: this article were defrayed in part by payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 USC section 1734 solely to indicate this fact
    04/2002;
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    ABSTRACT: Anxiety-related behaviours were evaluated across various tests in a 800 F 2 -intercross of the Roman high- and low-avoidance inbred rats. These tests either evoke unlearned (open field [OF]; plus-maze [PM]; hole-board [HB]; spontaneous activity [A]; and acoustic startle reflex [ASR]) or learned (classical fear conditioning [CFC]; and shuttlebox avoidance conditioning [SAC]), anxious/fearful responses. Using factor analysis (oblique rotation), we obtained a six-fold solution with 14 variables derived from all tests. These six factors represented SAC, CFC, PM anxiety, PM and OF activity, ASR anxiety, plus a mixed whole of anxious and activity variables (from OF and A), respectively. In searching for a smaller number of meaningful factors, we applied a three-factor solution that coherently corresponded with differentiated facets of fearfulness, rather than with the tests. Results showed that (1) measures of SAC and CFC strongly loaded onto Factor 1, labelled as "Learned Fear"; (2) a blend of almost all variables loaded onto Factor 2, called "Emotional Reactivity"; and (3) open arm behaviour in the PM loaded onto Factor 3, called "Fear of Heights." After discussing limitations of this apparently consistent behavioural map of anxiety, we advance some connections between those factors with quantitative trait loci candidates (genetic markers) as detected in the same sample [14]. 2002 Elsevier Science Inc. KEY WORDS: Factor analysis, Anxiety, Emotional reactivity, Fear, Aversive learning, Inbred Roman rats.
    03/2002;
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    ABSTRACT: Anxiety-related behaviours were evaluated across various tests in a 800 F(2)-intercross of the Roman high- and low-avoidance inbred rats. These tests either evoke unlearned (open field [OF]; plus-maze [PM]; hole-board [HB]; spontaneous activity [A]; and acoustic startle reflex [ASR]) or learned (classical fear conditioning [CFC]; and shuttlebox avoidance conditioning [SAC]), anxious/fearful responses. Using factor analysis (oblique rotation), we obtained a six-fold solution with 14 variables derived from all tests. These six factors represented SAC, CFC, PM anxiety, PM and OF activity, ASR anxiety, plus a mixed whole of anxious and activity variables (from OF and A), respectively. In searching for a smaller number of meaningful factors, we applied a three-factor solution that coherently corresponded with differentiated facets of fearfulness, rather than with the tests. Results showed that (1) measures of SAC and CFC strongly loaded onto Factor 1, labelled as "Learned Fear"; (2) a blend of almost all variables loaded onto Factor 2, called "Emotional Reactivity"; and (3) open arm behaviour in the PM loaded onto Factor 3, called "Fear of Heights." After discussing limitations of this apparently consistent behavioural map of anxiety, we advance some connections between those factors with quantitative trait loci candidates (genetic markers) as detected in the same sample.
    Brain Research Bulletin 02/2002; 57(1):17-26. · 2.94 Impact Factor
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    ABSTRACT: One of the major pathways for neurotransmitter signaling involves phosphoinositide-specific and G-protein-dependent phospholipase C-beta (PLC-beta), which stimulates the formation of inositol 1,4,5-trisphosphate and diacylglycerol. Serotonergic and muscarinic-cholinergic signals in the brain are largely mediated through the hydrolysis of phosphoinositides by PLC. The aim of the experiments reported here was to explore the potential differences in neurotransmitter receptor coupling to PLC in Roman high-avoidance (RHA)/Verh and Roman low-avoidance (RLA)/Verh rats, by examining the changes in agonist (carbachol, 5-methyltryptamine)-stimulated phosphoinositide hydrolysis in hippocampal and cortical membranes derived from the two rat lines. To investigate changes in receptor and G-protein coupling to PLC in the brains of these two psychogenetically selected rat lines, which differ in their emotional profiles/learning abilities, we examined GTPgammaS-, agonist (carbachol, 5-methyltryptamine)-, and calcium-stimulated phosphoinositide hydrolysis in cortical and hippocampal membranes of RHA/Verh and RLA/Verh rats. The results indicated that calcium-induced increase in PLC activity was larger in the cortex and hippocampus of RHA/Ver rats, as compared to their RLA/Verh counterparts. Conversely, GTPgammaS- and agonist-induced PLC activity was less pronounced in the hippocampus of RHA/Verh with respect to RLA/Verh rats. Western blot analysis showed no significant differences in the relative values of the G-proteins alphaq/11 and betagamma subunits between both groups of rats in any brain region. However, the levels of PLC-beta1, PLC-beta3, and PLC-beta4 were significantly lower in the hippocampus of RHA/Verh than in RLA/Verh rats. It is concluded that the hippocampus of RHA/Verh rats has severe deficiencies in PLC activity stimulated by guanine nucleotides and agonists, which are specifically related to a lower level of expression of the PLC-beta type isozymes, a fact that may account for the differential behavioral phenotype observed in these psychogenetically selected rat lines.
    Psychopharmacology 04/2001; 154(2):115-25. · 4.06 Impact Factor
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    ABSTRACT: Rationale: One of the major pathways for neurotransmitter signaling involves phosphoinositide-specific and G-protein-dependent phospholipaseC-β (PLC-β), which stimulates the formation of inositol 1,4,5-trisphosphate and diacylglycerol. Serotonergic and muscarinic-cholinergic signals in the brain are largely mediated through the hydrolysis of phosphoinositides by PLC. Objectives: The aim of the experiments reported here was to explore the potential differences in neurotransmitter receptor coupling to PLC in Roman high-avoidance (RHA)/Verh and Roman low-avoidance (RLA)/Verh rats, by examining the changes in agonist (carbachol, 5-methyltryptamine)-stimulated phosphoinositide hydrolysis in hippocampal and cortical membranes derived from the two rat lines. Methods: To investigate changes in receptor and G-protein coupling to PLC in the brains of these two psychogenetically selected rat lines, which differ in their emotional profiles/learning abilities, we examined GTPγS-, agonist (carbachol, 5-methyltryptamine)-, and calcium-stimulated phosphoinositide hydrolysis in cortical and hippocampal membranes of RHA/Verh and RLA/Verh rats. Results: The results indicated that calcium-induced increase in PLC activity was larger in the cortex and hippocampus of RHA/Ver rats, as compared to their RLA/Verh counterparts. Conversely, GTPγS- and agonist-induced PLC activity was less pronounced in the hippocampus of RHA/Verh with respect to RLA/Verh rats. Western blot analysis showed no significant differences in the relative values of the G-proteins αq/11 and βγ subunits between both groups of rats in any brain region. However, the levels of PLC-β1, PLC-β3, and PLC-β4 were significantly lower in the hippocampus of RHA/Verh than in RLA/Verh rats. Conclusions: It is concluded that the hippocampus of RHA/Verh rats has severe deficiencies in PLC activity stimulated by guanine nucleotides and agonists, which are specifically related to a lower level of expression of the PLC-β type isozymes, a fact that may account for the differential behavioral phenotype observed in these psychogenetically selected rat lines.
    Psychopharmacology 02/2001; 154(2):115-125. · 4.06 Impact Factor
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    ABSTRACT: In the present study, male inbred animals (from the 10th generation of an inbreeding program that has been carried out in parallel to that of the outbred Roman high- and low-avoidance rat lines), were compared for emotionality in different testing situations, exploratory behavior in the holeboard and two-way, active-avoidance acquisition. Compared to the inbred Roman high-avoidance (RHA-I/Verh) rats, inbred Roman low-avoidance (RLA-I-Verh) rats showed higher emotionality in the open field (reduced distance travelled and number of rearings, and increased self-grooming behavior), in the elevated plus-maze test (increased number of total and open-arm entries, reduced distance travelled in the open arms, and increased self-grooming behavior), and during the habituation period in the shuttle box (decreased number of crossings, increased self-grooming behavior and defecations). Results from the hyponeophagia test were not conclusive, probably due to the test-dependent hyperactivity shown by RHA-I/Verh rats. In the holeboard apparatus, RHA-I/Verh rats explored more than RLA-I/Verh rats, especially when novel objects were located beneath the holes. Finally, RHA-I/Verh animals rapidly acquired active, two-way (shuttlebox) avoidance, whereas RLA-I/Verh animals required four 50-trial sessions to achieve an assymptotic level of 30-40% avoidance. Thus, the behavioral patterns of the Roman inbred strains were very similar to those previously reported for the RHA/Verh outbred lines. Differences in locomotor activity, exploratory, and self-grooming behavior were actually greater between the inbred strains than between the outbred lines. Differences in defecation, however, although still significant, were not so pronounced as those noted previously at this laboratory with the outbred lines.
    Physiology & Behavior 09/1999; 67(1):19-26. · 3.16 Impact Factor
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    ABSTRACT: A comparison of sleep organization in Roman high-(RHA/Verh) and low-(RLA/Verh) avoidance rats, which differ in the way they respond to environmental stimuli and in several neuroendocrine and neurochemical parameters, was carried out. EEG-sleep recordings were obtained from adult males over 12:12 light-dark periods to determine how these two psychogenetically selected rat lines might also differ in their sleep-wake cycle. There was no significant difference in total sleep time between the two lines. However, the (hypoemotional) RHA/Verh rats showed an overall increase (percentage of total sleep) in paradoxical sleep (PS) duration, with a concomitant decrease in slow-wave sleep (SWS). During the dark phase, RHA/Verh rats showed a shorter PS latency and a larger number of PS episodes. Hourly sleep scoring also revealed a more discontinuous pattern (total sleep and PS vs. SWS) during the dark phase in RHA/Verh rats. In relation to recognized neurochemical and neuroendocrine differences between them, these rat lines may prove useful in investigations of the neurobiological mechanisms underlying sleep regulation.
    Journal of Biological Rhythms 07/1999; 14(3):221-6. · 3.23 Impact Factor
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    ABSTRACT: In the present study, male inbred animals (from the 10th generation of an inbreeding program that has been carried out in parallel to that of the outbred Roman high- and low-avoidance rat lines), were compared for emotionality in different testing situations, exploratory behavior in the holeboard and two-way, active-avoidance acquisition. Compared to the inbred Roman high-avoidance (RHA-I/Verh) rats, inbred Roman low-avoidance (RLA-I-Verh) rats showed higher emotionality in the open field (reduced distance travelled and number of rearings, and increased self-grooming behavior), in the elevated plus-maze test (increased number of total and open-arm entries, reduced distance travelled in the open arms, and increased self-grooming behavior), and during the habituation period in the shuttle box (decreased number of crossings, increased self-grooming behavior and defecations). Results from the hyponeophagia test were not conclusive, probably due to the test-dependent hyperactivity shown by RHA-I/Verh rats. In the holeboard apparatus, RHA-I/Verh rats explored more than RLA-I/Verh rats, especially when novel objects were located beneath the holes. Finally, RHA-I/Verh animals rapidly acquired active, two-way (shuttlebox) avoidance, whereas RLA-I/Verh animals required four 50-trial sessions to achieve an assymptotic level of 30–40% avoidance. Thus, the behavioral patterns of the Roman inbred strains were very similar to those previously reported for the RHA/Verh outbred lines. Differences in locomotor activity, exploratory, and self-grooming behavior were actually greater between the inbred strains than between the outbred lines. Differences in defecation, however, although still significant, were not so pronounced as those noted previously at this laboratory with the outbred lines.
    Physiology & Behavior - PHYSIOL BEHAV. 01/1999; 67(1):19-26.

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2k Citations
194.67 Total Impact Points

Institutions

  • 2005
    • Hôpitaux Universitaires de Genève
      Genève, Geneva, Switzerland
  • 1995–2003
    • ETH Zurich
      • Institute of Neurosciences
      Zürich, Zurich, Switzerland
  • 1994–2003
    • Università degli studi di Cagliari
      • Department of Environmental and Life Science
      Cagliari, Sardinia, Italy
  • 1991–2002
    • Autonomous University of Barcelona
      • Departamento de Medicina
      Cerdanyola del Vallès, Catalonia, Spain
  • 2001
    • Universidad del País Vasco / Euskal Herriko Unibertsitatea
      • Departamento de Farmacología
      Bilbao, Basque Country, Spain
  • 1998
    • University of Geneva
      • Department of Psychiatry
      Genève, GE, Switzerland
  • 1997
    • Eawag: Das Wasserforschungs-Institut des ETH-Bereichs
      Duebendorf, Zurich, Switzerland
    • Otto-von-Guericke-Universität Magdeburg
      • Institute for Anatomy
      Magdeburg, Saxony-Anhalt, Germany
  • 1993–1996
    • University of Delaware
      • Department of Psychology
      Newark, DE, United States
  • 1988–1989
    • University of Zurich
      • Institute of Veterinary Anatomy
      Zürich, ZH, Switzerland
  • 1986–1987
    • University of Lausanne
      Lausanne, Vaud, Switzerland
  • 1983–1986
    • Hebrew University of Jerusalem
      • Department of Psychology
      Yerushalayim, Jerusalem District, Israel