A cell surface molecule distributed in a dorsoventral gradient in the perinatal rat retina

Brain topography may have its earliest expression as spatial gradients of molecules controlling the deposition of neurones and neuronal processes. In the vertebrate visual system there is evidence that the stereotyped alignment of central retinal projections relies on an initial spatially organized distribution of molecules in both the retina and its central target nuclei. We used an immunological approach to look for molecules that are so organized and produced a monoclonal antibody (JONES) which shows a pronounced dorsal to ventral gradient of binding in the rat retina throughout the period when retinal ganglion cell axons are forming topographically organized projections within the central nervous system (CNS). Binding is present throughout the radial thickness of the retinal epithelium in regions where postmitotic neurones are generated but is not associated with any consistent histological characteristic of the tissue. The antibody was shown to bind on the cell surface of freshly dissociated retinal cells, and dorsal retinal quadrants were found in vitro to have nearly twice as much antigen as ventral retinal quadrants. Initial biochemical characterization of the target epitope reveals that it is a lipid present in chloroform/methanol extracts from perinatal retina and is sensitive to neuraminidase digestion.     

Specificity and reversibility of insulin binding to isolated thyroid nuclei

Inhibition studies of nuclear binding of labelled insulin by unlabelled insulin, proinsulin and polypeptide hormones (glucagon, GH, TSH) as well as kinetics of binding dissociation suggest that thyroid isolated nuclei specifically, at least pro parte, and reversibly bind to insulin.     

Regional brain [Met]-enkephalin in alcohol-preferring and non-alcohol-preferring inbred strains of mice

Summary Scrutiny of the data from these studies reveals that the C58/J alcohol-preferring mice have significantly lower baseline methionine-enkephalin levels in both the corpus striatum and hypothalamus compared to C3H/CHRGL/2 non-alcohol-preferring mice. In other brain regions in these two strains, specifically, pituitary, amygdala, midbrain, and hippocampus, analysis of methionine-enkephalin levels did not show any significant differences. This suggests that the hypothalamus may indeed be a specific locus involved in the regulation of alcohol intake, via the molecular interaction between neuroamines, opioid peptides, as they are influenced by genetics and environment.     

John Wheeler’s Desert Island: The conservatism of non-empirical physics

This paper argues that non-empirical physics, as paradigmatically embodied by string theory, is a conservative research program, in spite of appearances. John Wheeler's 1950s research program of "daring conservatism" is identified as another non-empirical research program that checks all the same boxes as string theory. This case study is used to further analyze the connection between conservatism and a non-empirical approach. It is concluded that the prime difficulty of non-empirical physics is not that it involves unbridled speculation, but that the lack of empirical input prevents it from achieving revolutionary progress.     

Narcotic antagonism of seizures induced by a dopamine-derived tetrahydroisoquinoline alkaloid

This paper describes experiments designed to evaluate whether the narcotic antagonist naloxone significantly interferes with seizures induced by tetrahydroisoquinolines (TIQs). In these experiments we found that naloxone significantly reduced seizure scores induced by intra-cranially infusing mice with 50 micrograms of the dopamine-derived tetrahydroisoquinoline (TIQ) alkaloid, 6,7-dihydroxy TIQ. These findings support an opioid involvement in the actions of TIQs and may lead to further understanding of opioid-mediated novel excitatory receptors.     

A health planner meets C. West Churchman

From 1966 to 1984, the author was professor of health planning at the School of Public Health of the University of California at Berkeley. During those years, he became a close colleague and friend of C. West Churchman, whose thinking on systems design became a Source of inspiration to him for rethinking many conventional patterns of thought in the field of health planning. In this paper, Henrik L. Blum draws a fine portrait of West Churchman, describing him as many of us who had the privilege of working with him—be it as colleagues or students—know him. (Editor)     

Narcotic antagonism of seizures induced by a dopamine-derived tetrahydroisoquinoline alkaloid

Summary This paper describes experiments designed to evaluate whether the narcotic antagonist naloxone significantly interferes with seizures induced by tetrahydroisoquinolines (TIQs). In these experiments we found that naloxone significantly reduced seizure scores induced by intra-cranially infusing mice with 50 g of the dopamine-derived tetrahydroisoquinoline (TIQ) alkaloid, 6,7-dihydroxy TIQ. These findings support an opioid involvement in the actions of TIQs and may lead to further understanding of opioid-mediated novel excitatory receptors.     

Linalool,neral and geranial in the mandibular glands ofColletes bees — an aggregation pheromone

Summary Mandibular glands of 3 species ofColletes were analyzed by combined gas chromatograph-mass spectrometry. Linalool, neral and geranial in 311 ratio were present and highly attractive to both sexes in field tests. Linalool has not previously been reported in Hymenoptera.Acknowledgment. We thank S. Vincent for assistance with field work and Ms E.F. Saker for permission to study bees nesting on her property.