Controlled creation of a singular spinor vortex by circumventing the Dirac belt trick

Persistent topological defects and textures are particularly dramatic consequences of superfluidity. Among the most fascinating examples are the singular vortices arising from the rotational symmetry group SO(3), with surprising topological properties illustrated by Dirac’s famous belt trick. Despite considerable interest, controlled preparation and detailed study of vortex lines with complex internal structure in fully three-dimensional spinor systems remains an outstanding experimental challenge. Here, we propose and implement a reproducible and controllable method for creating and detecting a singular SO(3) line vortex from the decay of a non-singular spin texture in a ferromagnetic spin-1 Bose–Einstein condensate. Our experiment explicitly demonstrates the SO(3) character and the unique spinor properties of the defect. Although the vortex is singular, its core fills with atoms in the topologically distinct polar magnetic phase. The resulting stable, coherent topological interface has analogues in systems ranging from condensed matter to cosmology and string theory

Experimental Psychopharmacology

Studies of psychopharmacology in experimental animals are a major source of information on the effects that drugs elicit on superior brain functions. Moreover, studies of psychopharmacology are a key step in the refinement of existing drugs and development of new drugs for the treatment of psychiatric diseases, such as anxiety, depression, and psychosis. The present chapter provides an overview of the techniques and animal models that can be used in studies of experimental psychopharmacology and discusses their strengths and limitations

Protective Agents in Parkinson's Disease: Caffeine and Adenosine A2A Receptor Antagonists

The pharmacologic management of Parkinson’s disease is based on drugs that act on the motor symptoms, whereas there are currently no drugs available that can alter the progressive neurodegeneration of dopaminergic neurons. Based on recent findings suggesting that the adenosinergic system is one of the most interesting in the field of neuroprotection in Parkinson’s disease, this chapter describes the functions of adenosine and its receptors in the central nervous system, with particular emphasis on their role in neurotoxicity/neuroprotection. Results of epidemiologic surveys demonstrating that intake of caffeine, an adenosine A1/A2A receptor antagonist, is inversely correlated with Parkinson’s disease are summarized. Moreover, evidence originating from preclinical studies showing that the antagonism of the adenosine A2A receptor is responsible for the neuroprotective effects of caffeine is also presented. This chapter therefore provides a comprehensive analysis of the current literature concerning the adenosinergic-based neuroprotective intervention strategy for Parkinson’s disease