The source of chilopod sensory information: External structure and distribution of antennal sensilla in Scutigera coleoptrata (chilopoda,Scutigeromorpha)

The investigation of the antennae of Scutigera coleoptrata (Linnaeus, 1758) by scanning electron microscopy (SEM) revealed the presence of five types of sensilla: sensilla trichodea, beak‐like sensilla, cone‐shaped sensilla brachyconica on the terminal article, sensory cones at the antennal nodes, and the shaft organ. Alongside the presence and absence of antennal sensillar types, three unique characters were found in the Scutigeromorpha: the presence of long antennae with nodes bearing sensory cones, the presence of a bipartite shaft including the shaft organ, and the presence of beak‐like sensilla. Neuroanatomical data showed that the animals' brains are equipped with well‐developed primary olfactory and mechanosensory centers, suggesting that the antennae must be equipped with specialized sensilla to perceive chemosensory and mechanosensory cues. With the evidence provided in this article for the Scutigeromorpha, SEM data are available at last on the antennal sensilla for all five chilopod taxa, allowing a comparative discussion of antennal morphology in Chilopoda. J. Morphol., 2011. © 2011Wiley‐Liss, Inc.     

Role of the vagus in control of the major conduit coronary artery in the dog.

Using El Badawi and Schenk's modification of Karnovski's method for the demonstration of acetylcholinesterase, the authors found cholinergic fibres both in the perivascular connective tissue and directly in the wall (in the adventitia) of the major coronary arteries; the fibres were distributed regularly around the circumference of the arteries. In the case of the smaller intramyocardial arteries, the cholinergic fibres were concentrated at two poles of the blood vessel; none were present in the wall of the veins. The shape and topography of the coronary cholinergic arterial plexus resemble the shape and topography of the coronary sympathetic adrenergic system. In apparent contradiction of this finding, stimulation of the cervical vagus did not affect the diameter of the large coronary arteries. Since acetylcholine (6--10 micrograms/kg i.v.) produced a mean 7.4% increase in the diameter of the ramus interventricularis ventralis, we concluded that there are no postgangliar cholinergic fibres of vasomotor significance for the large coronary arteries in the cervical vagus. The specific acetylcholinesterase activity found in the wall of these vessels belongs either to cholinergic terminals whose ganglion cells are not located in the vagal ganglion, or to cholinergic axones terminating outside the wall of the large coronary arteries.     

Die platyrrhinen affen als bewegungstypen. unter besonderer berücksichtigung der extremformen callicebus und ateles

Ohne Zusammenfassung     

The ability of collecting veins to sustain sympathetic constriction.

The collecting femoral vein is capable of sustaining contraction even for 15 minutes provided sympathetic stimulation frequency is low or moderate. At a frequency of 15 Hz, however, the collecting vein gradually relaxes after having reached a maximum contraction in spite of continuing stimulation. The ability of the relaxing venous smooth muscle to develop further contraction to exogenous noradrenaline has been proved. It seems probable that the relaxation is due to the decline in the amount of transmitter released from nerve terminals as a result of prolonged high rate stimulation.     

Orotate phosphoribosyltransferase and orotidylate decarboxylase from Crithidia luciliae: subcellular location of the enzymes and a study of substrate channeling

Orotate phosphoribosyltransferase (OPRTase) and orotidylate decarboxylase (ODCase) have been found to be particulate in the kinetoplastid protozoan, Crithidia luciliae. Sucrose density centrifugation indicated that these two enzymes are associated with the glycosome, a microbody which appears to be unique to the Kinetoplastida and which contains many of the glycolytic enzymes. The particulate location of OPRTase and ODCase was considered to be favorable for channeling of orotidine-5'-monophosphate (OMP), the product of the first enzyme and substrate for the second. The degree of channeling was determined by double radioactively labeled experiments designed to determine the relative efficiency of endogenous and exogenous OMP as substrates of ODCase. The efficiency of channeling was high, with an approximate 50-fold preference for endogenous OMP. By comparison, the degree of channeling for the yeast enzymes, which are soluble and unassociated, was less than 2-fold. The OPRTase-ODCase enzyme complex was solubilized using Triton X-100 in the presence of dimethyl sulfoxide, glycerol, and phosphoribosyldiphosphate. The percentage recovery of the overall enzyme activity was approximately 20%. The degree of channeling was reduced by approximately 10-fold for the solubilized complex. The Km for OMP changed from 7.5 (+/- 1.8) to 1.6 (+/- 0.3) microM in the ODCase reaction. There was no alteration in the Km for orotate in the OPRTase reaction.