[Dimensional personality assessment of the members of the French junior national team of road cycling]. / Evaluation dimensionnelle de personnalité des membres de l'équipe de France junior de vélo sur route.

The high-standard sport practice requires an optimum functioning level of the individual in all its physiological systems as a whole. If the physical program training progressed much these last years, the techniques of mental preparations are still very heterogeneous and are not based on any validated procedures, based only on individual practices. Nevertheless, the majority of athletes and trainers stress the major importance of "mental" in the realization of performances. One of the obstacles in the mental training of the athletes is the difficulty in finding tools making it possible to evaluate and measure the psychic state of the individual and its mode of coping and adjustment, apart from any psychopathology. Few studies have been carried out on applicability of the personality questionnaires derived from the current dimensional models in these populations. Our study aimed to describe the personality of the members of the french junior team of road cycling, using the Temperament and Character Inventory (TCI) developed by Cloninger to explore the seven dimensions of his psychobiologic model of personality. In this model, four dimensions are temperament factors, and three are character factors. The three main dimensions of temperament are Novelty Seeking (NS), ie the tendency towards excitement in response to novel or rewarding stimuli, Harm Avoidance (HA) hypothesized to represent the tendency to respond intensely to signals of adverse stimuli, and Reward Dependence reflecting the tendency to respond intensely to signals of reward and to maintain behavior previously associated with reward. These personality traits are hypothetically related to underlying neurotransmitter systems (especially NS to dopaminergic function and HA to serotonergic function). The two main dimensions of character are Self-Directedness (SD) and Cooperativeness (C), measuring maturity traits respectively concerning individual and social adaptation. In this study, we used a computerized version of the TCI in a sample of 18 racing cyclists, ie all the members of the french junior national team. Their results were compared to those of 26 male, young, community subjects, derived from the french normative validation sample of the TCI. Mean comparisons were performed with the Mann-Whitney test, with Bonferroni correction for multiple comparisons. A significant difference between subjects and controls was obtained for Reward Dependence (p<0.0001), attachment RD3 (p<0.0001), and dependence RD4 (p<0.0025). No significant difference appeared between both groups for the other temperament or character dimensions. Based on temperamental Cloninger typology, the type "passionate" appeared to be the most frequent in this sample (55.6%). These results suggested that the TCI can be easily and usefully used in athletes, and that the personality profile of young competitive cyclists is not abnormal except a high level of reward dependence. Numerous applications can be derived from this use: the development of specific and personalized mental training, the screening and prevention of psychological vulnerability.

The endogenous cerebral tetrapeptide 5-HT-moduline reduces in vivo the functional activity of central 5-HT1B receptors in the rat.

5-HT-moduline (Leu-Ser-Ala-Leu, LSAL) is a novel endogenous peptide isolated from rat brain which interacts in vitro specifically with 5-HT(1B) receptors by a non-competitive mechanism. In the present study, we demonstrate that the efficacy of the selective 5-HT(1B) receptor agonist CP 93 129 in inhibiting the forskolin-stimulated adenylyl cyclase activity in the rat substantia nigra was reduced 15 min after intracerebral injection of LSAL compared to vehicle or ALLS (scrambled peptide) injected rats. Accordingly, the concentration-response curve of the agonist is shifted to the right with a 3.5-fold increase of the half-maximal inhibitory concentration compared to vehicle injected rats. Thus, the in vivo desensitization of serotonergic autoreceptors strongly strengthens the important role of 5-HT-moduline in the rapid adaptative control of the serotonergic system, implicated in numerous pathological events as anxiety and depression.