Glutamatergic axons from the lateral habenula mainly terminate on GABAergic neurons of the ventral midbrain.

The concept of cortical-subcortical loops emphasizes the importance of the basal ganglia for motor, psychomotor, and emotional cortical functions. These loops are bidirectionally controlled by the midbrain dopaminergic system, predominantly but not exclusively at the level of the striatum including the accumbens nucleus. Successful behaviors increase the activities of the mesostriatal (arising in the complex part of the substantia nigra) and mesolimbic (arising in the ventral tegmental area, VTA) neurons, thereby reinforcing the corresponding actions. In contrast, unsuccessful behaviors result in an increased activation of the lateral habenular complex (LHb), thereby decreasing the activities of mesolimbic neurons. Correspondingly, electrical stimulation of the LHb effectively blocks neuronal activity in the VTA. Whether this block is due to an inhibitory projection from the LHb to the VTA, or whether axons from excitatory LHb neurons target inhibitory neurons within the VTA, is presently not known. Here we show, using in situ hybridization and immunocytochemical double labeling at the light and electron microscopic level, that GABAergic neurons are scarce in the LHb and that glutamatergic axons from the LHb mostly target GABAergic neurons in the VTA and the mesopontine rostromedial tegmental nucleus (RMTg), also known as tail of the VTA (tVTA). These data explain the inhibitory effect of LHb activation on the VTA. In addition, however, a small number of LHb terminals in the VTA actually contacts dopaminergic neurons. The biological importance of these terminals requires further investigation.

[Population projections: goals, methods, hypotheses]. / Les projections de population : objectifs, méthodes, hypothèses.

Population projections generally use the component method which consists in adapting sample size by age and sex from mortality, fertility and migration hypotheses. This exercise is not always aimed a providing projection data, but may also serve to analyze factors changing in the population. Comparatively long-term demographic forecasts, particularly for mortality, can be made due to the major inertia of demographic phenomena. However, the quality of such predictions depends on the quality of knowledge of past evolution in the demographic factors and on the capacity to forecast their future evolution.

The form of marriage in Europe: civil ceremony, religious ceremony. Survey and trends.

The author examines trends in the distribution of civil and religious marriage ceremonies in Europe over time. Information is provided on marriages among different religious groups in Central, Southern, and Northern Europe. "In many countries the proportion of religious marriages is declining, in others it shows little change, while in others it is on the increase.... In some countries their decline precedes that in the total number of marriages, in others it follows it, while in others the two movements coincide. Hypotheses have been advanced to explain these different developments, based on the socio-political and institutional contexts. These contexts can now usefully be reviewed, not in order to make forecasts, but to indicate the course of possible future developments."

[Recent trends in divorce in France: some comparisons with the Czechoslovak republics]. / L'evolution recente de la divortialite en France: quelque comparaisons avec les republiques tchecoslovaques.

PIP: The first part of this article presents a demographic analysis of differences in divorce patterns between France and Czechoslovakia. The second part examines social factors affecting divorce in France.^ieng