Inhibitory influence of frontal cortex on locus coeruleus neurons.

The functional influence of the frontal cortex (FC) on the noradrenergic nucleus locus coeruleus (LC) was studied in the rat under ketamine anesthesia. The FC was inactivated by local infusion of lidocaine or ice-cold Ringer's solution while recording neuronal activity simultaneously in FC and LC. Lidocaine produced a transient increase in activity in FC, accompanied by a decrease in LC unit and multiunit activity. This was followed by a total inactivation of FC and a sustained increase in firing rate of LC neurons. Subsequent experiments revealed antidromic responses in the FC when stimulation was applied to the LC region. The antidromic responses in FC were found in a population of neurons (about 8%) restricted to the dorsomedial area, FR2. The results indicate that there is a strong inhibitory influence of FC on the tonic activity of LC neurons. The antidromic responses in FC to stimulation of the LC region suggest that this influence is locally mediated, perhaps through interneurons within the nucleus or neighboring the LC.

Tab. 1: Rates of advance of the frontal push-moraines of 19 lobes in front of an approx. 4.5 km long margin of the Kötlujökull

In the last years masses of ice, about 5 km long, have been protruding from the lowest part of an advancing glacier margin of the Kötlujökull in Southern Iceland. In the summer of 1983, they appeared as sediment-covered lobes, 10-60 m long, bordering the glacier rnargin like agarland. 1 to 3 push-rnoraines without ice core, rnostly sickle-shaped, occured first in the frontal parts of the lobes: behind thern came several ice-cored moraines with heights of up to several metres. The active ice in front of the precipice of the glacier is called the "glacier-foot" in this paper. The digging out of 9 lobes and the measuring of the advance of 19 lobes showed that in most cases this glacierfoot had split up at its distal end into several plate- or stem-shaped pieces of ice which were situated one upon the other, separated by moraine deposits and proceeding irregularly into the foreland at the rate of several mm/h, The sometimes different rate of advance in the same lobe and different rates of advanee in adjoining lobes (some being entirely inactive) point to a type of rnovement which is independent of the general advance of the glacier. Research in the winter of 1983/84 showed less activity in 3 examined lobes, but the activity had not ceased. The advancement of the lower parts of the glacier-foot into and across the sands of the foreland implies the following genesis of pushmoraines: Shoving off a plate of sand, folding it and pushing it over the foreland at average rates of up to 7,2 mm/h, according to the investigations in thc summer of 1983. At a certain stage of the folding process, new folds begin to develop in front of the old, and the old folds are shifted onto the backslope of thc folds in front of them until they are completely unired. In this way, "püe-moraines" arise, which become higher and higher. They include two or more folds declining towards the glacier. Systems of small moraines presumably of the same genesis occur on old moraine areas in front of the Kötlujökull. The possible cause of formation of a glacier-foot is discussed, and the moraines of the Kötlujökull are compared with certain pleistocene push-moraines.

A 1995 Solectria 4-door sedan into flat frontal barrier at 48.1 kph. Final report.

National Highway Traffic Safety Administration, Office of Vehicle Safety Compliance, Washington, D.C.

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National Highway Traffic Safety Administration, Washington, D.C.

Research MIV (modified integrated vehicle). Volume II/1 - frontal impact. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

A 1995 Solectria E-10 pickup into flat frontal barrier. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

A 1993 Solectria Force into a flat frontal barrier. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

A 1993 Sebring Zev into flat frontal barrier. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Minicars Research Safety Vehicle to 1979 Dodge Challenger crash test report - frontal aligned impact at 86.52 mph closing speed.

National Highway Traffic Safety Administration, Office of Vehicle Safety Compliance, Washington, D.C.

Research safety vehicle (RSV) crash test report: test no. 3054-1 - 41 mph flat barrier frontal impact. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Final report of a 1993 Solectria Force into flat frontal barrier.

National Highway Traffic Safety Administration, Washington, D.C.

A 1991 Ford F150 pickup frontal impact: CNG fuel tank integrity. Final report.

Mode of access: Internet.

Occupant response and vehicle acceleration in a 30 mph frontal impact test - 1981 Ford F150 Custom Explorer Styleside - Pickup - NHTSA 810602. Final report.

National Highway Traffic Safety Administration, Office of Passenger Vehicle Research, Washington, D.C.