Effects of glutamate, aspartate, and two-presumed antagonists on feline rubrospinal neurones

The actions of dicarboxyl amino acids (GLUT, ASP, DLH) and of presumed amino acid antagonists (GDEE, HA 966) were studied in rubrospinal neurones with microelectrophoretic techniques. ASP and GLUT depolarized reversibly the cell membrane and increased its conductance. ASP had slightly stronger actions than GLUT. DLH had strong depolarizing actions without a clearcut change in membrane conductance; this may be due to the fact that DLH effects do not involve synaptic receptors. A specific action as antagonists for GLUT could not be shown for GDEE or HA 966. HA 966 effects were often accompanied by apparent postsynaptic actions. GDEE antagonized DLH effects sometimes even stronger than GLUT effects. The effects of GLUT and ASP are in principal agreement with a function as excitatory transmitters. The demonstration of a role as transmitter substances in excitatory (e.g. corticorubral or interpositorubral) pathways, however, still awaits the specific pharmacological antagonist.

Effects of GABA, glycine, picrotoxin and bicuculline methochloride on rubrospinal neurones in cats

A microelectrophoretic study was performed of the actions of GABA and glycine, and of their antagonists on rubrospinal neurones. GABA and glycine depressed antidromic and synaptic potentials, hyperpolarized the cell membrane and increased the membrane conductance. GABA was more effective than glycine. Corticorubral IPSPs and the GABA-induced membrane hyperpolarization could be reversed by intracellular application of hyperpolarizing currents. Picrotoxin and bicuculline methochloride antagonized inhibitory GABA actions and the corticorubral IPSP or the corresponding extracellular positive field potential. The results support the hypothesis that GABA is the transmitter of the corticorubral inhibition in the cat.

A tungsten electrode insulated by a concentric arrangement of glass-pipettes for iontophoresis

A method is described by which electrolytically sharpened tungsten wires were coated with a coaxial assembly of 5-8 glass-capillaries. This glass coating provides good insulation and high rigidity of the tungsten electrodes. The glass pipettes were used for electrophoretic ejection of test substances and the tungsten electrode for extracellular recording of neuronal activity.

Role of commercial aircraft in global monitoring systems

The role of commercial aircraft in monitoring meteorological parameters and atmospheric constituents has been limited in the former case and virtually nonexistent in the latter. I have tried to point out that this situation can and should be changed now. The new family of wide-bodied jets such as the 747, DC-10, and L-1011 aircraft can be used to supply important global atmospheric and tropical meteorological data for which there is a pressing need. While scientists are not in total agreement on the magnitude of the effect of particulates and gases on the atmosphere, there is almost unanimous concurrence that we are severely limited in information, and that global baseline concentrations must be established for particulates and gases in the troposphere and lower stratosphere as soon as possible. Also, more synoptic meteorological information from the tropical troposphere is highly desirable. In the final analysis, commercial aircraft may offer the most inexpensive way to monitor our atmosphere in the near future. Much of the instrumentation technology is here and the rest is certainly within our grasp. The fact of the matter is that there are now over 220 Boeing 747's and Douglas DC-10's in service, flying an average of 10 hours a day. Long-range flights, such as those from Tokyo to Anchorage to London in the Northern Hemisphere and from Hawaii to Pago Pago to Sydney in the Southern Hemisphere, are commonplace. These aircraft are equipped with inertial navigation systems and central air data computers coupled to advanced data storage systems which can readily be interrogated by satellite. This means that there is now a large amount of snyoptic weather information which can be obtained with a minimum of effort and cost. Likewise, a start at obtaining measurements of atmospheric constituents on a global basis can be made now. All we need to do is make the effort.