NCS-1 (neuronal calcium sensor) is a recently characterized member of a highly conserved neuron-specific family of calcium-binding proteins, which also includes frequenin and recoverin. The cellular and subcellular distributions of NCS-1 in the rat nervous system were investigated using light- and electron-microscopic immunohistochemistry. NCS-1 immunoreactivity was localized to neuronal cell bodies and axons throughout the brain and spinal cord but not to glial cells. The most intense labeling was observed in myelinated axons, the axonal ramifications of the basket cell in the cerebellar cortex, and large neurons in the brainstem and pons. These same structures were also characterized by heavy labeling for neurofilament protein, as determined by double-labeling experiments. Most axon terminals were unlabeled or only lightly labeled. The most remarkable subcellular staining occurred in the perikarya where intense labeling was associated with the membranes of the trans saccules of the Golgi apparatus. The widespread distribution of NCS-1 indicates that it may be active in a variety of calcium-dependent neuronal functions, whereas the specific subcellular localization to the Golgi apparatus and neurofilament-rich structures suggests a specialized role in calcium regulated protein trafficking and cytoskeletal interactions.

Three models for the perception of odor molecules are suggested for the first time by experimental data. These studies illustrate how the nose may smell. Moreover, they suggest additional role(s) for odor receptors within and outside the olfactory system.

Neural Ca2+-binding proteins (NCaPs) constitute a subfamily of 4-EF-hand proteins, and display a histological and structural dichotomy: the A-type NCaPs are selectively expressed by the retina and pineal organ and display two canonical EF-hands, whereas the B-type NCaPs are found in the entire brain and present three regular EF-hands. In this study, antisera were raised against the A-type NCaP recoverin (26 kDa) and the B-type NCaPs VILIP and NCS-1 (22 kDa). Since the sequence identity among NCaPs is high, specific polyclonal antibodies were purified by double cross-immunoaffinity chromatography; both ELISA and immunoblot analyses determined that the resulting antibodies showed selectivity ratios inferior to 1/363 for the two other related NCaPs. Besides, the anti-VILIP antibodies displayed some affinity toward neurocalcin δ, and the antirecoverin antibodies recognized a 24 kDa protein, which is most likely visinin. Thus, immunohistochemical studies on the chicken, rat and cow retina revealed that anti-recoverin antibodies recognized the vertebrate photoreceptors and a small number of mammalian bipolar cells. Anti-VILIP antibodies exclusively labelled the inner Retina, I.e. the amacrine and ganglion cells. NCS-1 was mainly present in the photoreceptor inner segments, the inner plexiform layer and the ganglion cells. NCS-1 showed the highest species disparity. The retinal localization of NCS-1 and VILIP offered an important morphological basis for the understanding of their function. Furthermore, specific antibodies against the NCaPs may enable the identification of cell populations in more complex neural tissues, such as the brain.

In vertebrates, the nicotinic acetylcholine receptor (nAChR) present in the post-synaptic membrane of electrocytes or squeletal muscle cells is very well characterised biochemically (Changeux et al., 1984) and physiologically (Sakmann et al., 1983). In contrast, the related cholinergic receptors found in the central or peripheral nervous system are poorly understood. In the past few years, however, significant progress has been made in the identification and functional characterisation of neuronal nAChRs. Progress has resulted mainly from two different experimental approaches: the use of monoclonal antibodies has allowed the localisation, functional identification and purification of several distinct neuronal cholinoceptor species (Jacob et al., 1984; Whiting and Lindstrom 1986, 1987; Whiting et al., 1987) while molecular biological techniques have resulted in the isolation of numerous genes and cDNA clones encoding neuronal proteins that are related in sequence to the muscle endplate nAChR subunits (in rodents: Boulter et al., 1986; Goldman et al., 1987; Wada et al., 1988; Deneris et al., 1988; in birds: Nef, 1986; Nef et al., 1988).

1.1. Pig coronary smooth muscle cells contain a highly active fatty acid β-oxidation system as well as significant activities of other enzymes involved in lipid metabolism, i.e. palmitoyl-CoA synthetase, glycerophosphate acyl transferase, acetyl-CoA carboxylase and fatty acid synthetase.2.2. Purified plasma membranes of pig coronary smooth muscle cells contain stereospecific (−)-[3H]dihydroalprenolol binding sites of high affinity (Kd = 5.4nM) and characteristic of the β1 subtype. They also contain an adenylate cyclase activity which is stimulated by 5′-guanylyl-imidodiphosphate (Gpp(NH)p) and, to a lesser degree, by (–)-isoproterenol.