Interaction between the 5-HT system and the basal ganglia: functional implication and therapeutic perspective in Parkinson's disease

The neurotransmitter serotonin (5-HT) has a multifaceted function in the modulation of information processing through the activation of multiple receptor families, including G-protein-coupled receptor subtypes (5-HT1, 5-HT2, 5-HT4-7) and ligand-gated ion channels (5-HT3). The largest population of serotonergic neurons is located in the midbrain, specifically in the raphe nuclei. Although the medial and dorsal raphe nucleus (DRN) share common projecting areas, in the basal ganglia (BG) nuclei serotonergic innervations come mainly from the DRN. The BG are a highly organized network of subcortical nuclei composed of the striatum (caudate and putamen), subthalamic nucleus (STN), internal and external globus pallidus (or entopeduncular nucleus in rodents, GPi/EP and GPe) and substantia nigra (pars compacta, SNc, and pars reticulata, SNr). The BG are part of the cortico-BG-thalamic circuits, which play a role in many functions like motor control, emotion, and cognition and are critically involved in diseases such as Parkinson's disease (PD). This review provides an overview of serotonergic modulation of the BG at the functional level and a discussion of how this interaction may be relevant to treating PD and the motor complications induced by chronic treatment with L-DOPA.

Expression and Localization of Opioid Receptors in Male Germ Cells and the Implication for Mouse Spermatogenesis

The presence of endogenous opioid peptides in different testicular cell types has been extensively characterized and provides evidence for the participation of the opioid system in the regulation of testicular function. However, the exact role of the opioid system during the spermatogenesis has remained controversial since the presence of the mu-, delta-and kappa-opioid receptors in spermatogenic cells was yet to be demonstrated. Through a combination of quantitative real-time PCR, immunofluorescence, immunohistochemistry and flow cytometry approaches, we report for the first time the presence of active mu-, deltaand kappa-opioid receptors in mouse male germ cells. They show an exposition time-dependent response to opioid agonist, hence suggesting their active involvement in spermatogenesis. Our results contribute to understanding the role of the opioid receptors in the spermatogenesis and could help to develop new strategies to employ the opioid system as a biochemical tool for the diagnosis and treatment of male infertility.

Arsenic level in the surface wastewaters of Kolkata and its implication on sewage-fed fisheries

Arsenic pollution is a major threat in eastern India and Bangladesh. In Kolkata, sewage-fed fishery is a very popular culture. Wastewater of Kolkata city is diluted with freshwater and used in sewage-fed fish ponds. In the present study the arsenic concentration in the surface wastewater from forty-four different places of southern, eastern, western and norther parts of Kolkata was estimated. In fifteen places, the arsenic level was higher than the allowed limit (0.20 mg/l). But the arsenic level in the waters, sediment of fish culture ponds and in fish flesh of sewage-fed fisheries of Kolkata was below the maximum limit. So, till date there is no threat from arsenic pollution to the sewage-fed fisheries of Kolkata.

Seasonal change in the structure of fig-wasp community and its implication for conservation

Figs (Moraceae) and their pollinating wasps (Agaonidae) constitute a famous reciprocal mutualism in which figs provide some female flowers for the development of fig wasp offspring while the fig wasps pollinate Fig flowers. However, figs also host many no

Genetic diversity and taxonomic implication of Cordyceps sinensis as revealed by RAPD markers

Random amplified polymorphic DNA (RAPD) markers are used to investigate genetic variation and evolutionary relationships of 29 samples of Cordyceps sinensis from different geographical populations on the Qinghai-Tibet plateau. Out of 137 RAPD bands scored, 100 are polymorphic. A correlation is revealed between geographical distance and genetic distance. The molecular phylogenetic tree suggests that the 29 samples are divided into three notable clusters, corresponding to the geographical populations, i.e., the north population (NP), middle population (MP), and south population (SP). The NP consists of 7 northern samples from Menyuan, Maqu, and Luqu, the MP consists of 8 samples from Yushu and Chengduo, and the SP consists of 14 samples from Byma Snow Mountain, Renzhi Snow Moutain, Chongcaoxiwa, and Dacaodi. It is demonstrated that extensive genetic diversity is found among different geographical populations of C. sinensis. The genetic diversity pattern of C. sinensis may be caused by the founder effects. The taxonomic status of NP, MP, and SP populations should be that they are different subspecies rather than different species.