Behavioral response of 12 ungulate species in captivity to the presence of humans

Twelve species of captive ungulates were studied to determine behavioral responses to the presence of a zookeeper within the exhibit and in front of the exhibit, with and without zoo visitors present. Significant differences in behavior occurred between species for nearly all behaviors observed. A significantly greater occurrence of vigilance and approach behavior was directed toward the zookeeper while within the exhibit relative to when the zookeeper stood in front of the exhibit. A significantly lower occurrence of eating or drinking occurred when the zookeeper was inside the exhibit. Significant differences occurred across size categories in the occurrence of approaching the zookeeper. The most frequently scored behavior was visual orientation. Statistically significant differences in the occurrence of visual orientation directed by females toward the zookeeper existed across size category, with more vigilance by species with larger body size. A statistically higher occurrence of vigilance toward the zookeeper was directed by female ungulates but not by males when the zoo was closed to the public. Although no statistical significance was found regarding the intraspecific vigilance of males, data on females revealed significant differences across species and across size categories. When data regarding vigilance toward the public were analyzed, statistically significant differences existed between species for females only. Likewise, when data regarding interspecific vigilance were examined, statistically significant differences were found across size categories for females, but not for males. The potential roles of vigilance in the wild are discussed in reference to its role in captivity.     

[3H]1-Methyl-4-Phenyl-2,3-Dihydropyridinium Ion Binding Sites in Mouse Brain: Pharmacological and Biological Characterization

Because 1-methyl-4-phenyl-2,3-dihydropyridinium ion (MPP+) appears to damage the dopaminergic neuron and cause neuronal death, we characterized [3H]MPP+ binding sites in mouse brain membranes. Among several compounds tested, debrisoquin [3,4-dihydro-2(1H)-isoquinolinecarboxamidine] and some analogues were able to antagonize [3H]MPP+ binding. Debrisoquin is able to block adrenergic transmission and inhibit the activity of monoamine oxidase A (MAO-A). We found a certain correlation between the ability of these agents to displace [3H]MPP+ from its binding sites and their capacity to inhibit MAO-A activity. These data and the finding of a higher number of [3H]MPP+ binding sites in human placenta compared to mouse brain suggest that these sites may correspond to MAO-A enzymes. Recently it has been demonstrated in human brain that neurons in regions rich in catecholamines are positive for MAO-A. Accordingly, we suggest MAO-A as a possible accumulation site of MPP+ within the dopaminergic neuron. We also indicate the chemical structural requirement associated with the best binding of debrisoquin analogues with [3H]MPP+ sites. It would be reasonable to test the effects of debrisoquin-like drugs able to pass the blood-brain barrier on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine toxicity.     

Hypohidrotic ectodermal dysplasia

Summary A family carrying the X-linked gene for hypohidrotic ectodermal dysplasia (hereditary ectodermal polydysplasia or Christ-Siemens-Touraine syndrome) over three generations was monitored for more than 15 years. Two prenatal diagnoses were carried out by fetoscopy on skin biopsies. Polymorphic probes were used in the segregation analysis of the Xq11–21 region carried out on 30 members of the family. Current screening possiblitities for the carriers and prenatal diagnosis are discussed.     

Change in stereospecificity of bovine lens aldose reductase modified by oxidative stress

Bovine lens aldose reductase (alditol:NADP+ oxidoreductase, EC 1.1.1.21) undergoes an oxidative modification, greatly stimulated by high ionic strength, upon incubation in the presence of oxygen radical generating systems (Del Corso, A., Camici, M., and Mura, U. (1987) Biochem. Biophys. Res. Commun. 148, 369-375). The enzyme modification is accompanied by a change in stereospecificity toward the two enantiomers of glyceraldehyde. In particular, the Km for L-glyceraldehyde of the native form increased over 150 times after the enzyme modification, with a decrease in the catalytic efficiency of over 200 times. By contrast, for the D-enantiomer the Km increased only 7 times with respect to the native form, with a concomitant decrease in the catalytic efficiency of only approximately 3 times. This dramatic change in stereospecificity may account for the reported apparent cooperative behavior exhibited also by highly purified electrophoretically homogeneous preparations of aldose reductase.     

Do synapsin I and microtubule-associated proteins bind to a common site on polymerized tubulin?

Synapsin I plays an important role in the regulation of neurotransmitter release, since it binds to synaptic vesicles and to the cytoskeleton, and it bundles F-actin and microtubules. We have previously shown by tryptic digestion of synapsin I that a 44 kDa fragment contains a binding site for polymerized tubulin. In the present experiments, we test whether synapsin I and microtubule-associated proteins (MAPs) have the same or a different binding site on tubulin molecules. Our results show that heat stable MAPs do not compete with synapsin I for binding to taxol tubulin. In addition, subtilisin digestion of tubulin, which suppresses MAPs binding, does not abolish synapsin I cosedimentation with taxol tubulin. Thus, our results strongly suggest that synapsin I (as reported for kinesin) does not bind to the 4 kDa subtilisin digested C-terminal part of the tubulin molecule.     

Selective translocation of protein kinase C-delta in PC12 cells during nerve growth factor-induced neuritogenesis.

The specific intracellular signals initiated by nerve growth factor (NGF) that lead to neurite formation in PC12 rat pheochromocytoma cells are as of yet unclear. Protein kinase C-delta (PKC delta) is translocated from the soluble to the particulate subcellular fraction during NGF-induced-neuritogenesis; however, this does not occur after treatment with the epidermal growth factor, which is mitogenic but does not induce neurite formation. PC12 cells also contain both Ca(2+)-sensitive and Ca(2+)-independent PKC enzymatic activities, and express mRNA and immunoreactive proteins corresponding to the PKC isoforms alpha, beta, delta, epsilon, and zeta. There are transient decreases in the levels of immunoreactive PKCs alpha, beta, and epsilon after 1-3 days of NGF treatment, and after 7 days there is a 2.5-fold increase in the level of PKC alpha, and a 1.8-fold increase in total cellular PKC activity. NGF-induced PC12 cell neuritogenesis is enhanced by 12-O-tetradecanoyl phorbol-13-acetate (TPA) in a TPA dose- and time-dependent manner, and this differentiation coincides with abrogation of the down-regulation of PKC delta and other PKC isoforms, when the cells are treated with TPA. Thus a selective activation of PKC delta may play a role in neuritogenic signals in PC12 cells.