SAP90, a rat presynaptic protein related to the product of the Drosophila tumor suppressor gene dlg-A.

A novel synapse-associated protein, SAP90, accumulates around the axon hillock of Purkinje cells in rat cerebellum. By immuno-electron microscopy, SAP90 has been localized to the presynaptic termini of basket cells forming inhibitory, gamma-aminobutyric acid (GABA)ergic synapses onto Purkinje cell axon hillocks. The amino acid sequence for SAP90 has been deduced from the nucleotide sequence of a series of overlapping cDNA clones. SAP90 is related to the gene product encoded by the Drosophila tumor suppressor gene dlg-A. SAP90 and the dlg-A product share an overall sequence identity of 54%. Three distinct domains can be identified: (i) a potential cytoskeletal region consisting of three repeats of 90 amino acids in length, (ii) a domain with similarity to SH3, a putative regulatory motif found in the src family of non-receptor protein tyrosine kinases and several proteins associated with the cortical cytoskeleton, and (iii) a carboxyl-terminal domain homologous to yeast guanylate kinase. These features suggest a possible role for SAP90 in a guanine nucleotide-mediated signal transduction pathway at a subset of GABAergic synapses in the rat cerebellum.

A brain atlas of the northern fulmar (Fulmarus glacialis) in stereotaxic coordinates.

The brain of a procellariiform bird, the Northern Fulmar (Fulmarus glacialis), is presented in the form of a stereotaxic atlas. The Northern Fulmar is especially interesting because both field and laboratory evidence support olfaction as one of its major sensory systems. The nasal cavity and olfactory bulb of most procellariiforms are among the largest of all avian orders; the central olfactory pathways may be more extensive as well. A brain atlas of the Northern Fulmar, a relatively accessible procellariiform species on which several studies have already been done, can provide reference for research both on neural mechanisms underlying olfaction and on comparative neuroanatomical data within Aves and between avian and nonavian groups.

Decision to enter pulmonology: motives and implications.

A study was undertaken to determine at what time American-trained pulmonary disease specialists in two California counties made their subspecialty choices and the factors which influenced their decision. Responses to 281 questionnaires were received and analyzed from 171 fellows, faculty members, and practitioners (60.8 percent). Subspecialty decisions for pulmonology were usually made during residency, motivated by pulmonary rotations and exposure to stimulating faculty members. Although this subspecialty has recently developed into an established, growing field, the survey data confirmed that the amount of pulmonary interaction during medical school remains minimal.

Forebrain projections of the pigeon olfactory bulb.

The olfactory system of the pigeon (Columba livia) was examined. Our electrophysiological and experimental neuroanatomical (Fink-Heimer technique) data showed that axons from the olfactory bulb terminated in both sides of the forebrain. The cortex prepiriformis (olfactory cortex), the hyperstriatum ventrale and the lobus parolfactorius comprised the uncrossed terminal field. The crossed field included the paleostriatum primitivum and the caudal portion of the lobus parolfactorius, areas which were reached through the anterior commissure. In this report the relationships between areas that receive olfactory information and the possible roles that olfaction plays in the birds' behavior are discussed.

Techniques to prevent olfactory nerve reconstitution in the pigeon.

Transectioned olfactory nerves in birds can reestablish structural and functional connections with the olfactory bulbs in comparatively short time spans, thereby hampering long-range studies of avian olfaction and behavior. Accordingly, techniques are described that are suitable for impeding the reconstitution of the olfactory nerve after its transection in the pigeon. These involve the use of inexpensive and easily obtainable materials including cotton pellets, glass beads, and polyethylene tubing.