Potentiation effects in the dentate gyrus of pentylenetetrazol-kindled rats.

The study examines changes in the function of perforant pathway dentate granule cell synapses after pentylenetetrazol (PTZ) kindling. Field potentials evoked in the dentate area by test stimuli to the perforant pathway were recorded in freely moving rats at different times after injection of PTZ. In fully kindled animals, but not in sham-kindled controls, subconvulsive test doses of PTZ induced long-lasting potentiation of the population spike.

PTZ-kindling after colchicine lesion in the dentate gyrus of the rat hippocampus.

Pentylenetetrazol (PTZ)-kindling represents a model of a primarily generalized epilepsy. We investigated the role of the dentate gyrus of the hippocampus in this model of epilepsy by destruction of this structure by colchicine, injected in the dorsal and ventral hippocampus of rats. After a period of 7 days PTZ-kindling was started.

Pharmacological effects on two inbred substrains of AB mice.

Mice of the two substrains AB/Gat and AB/Hal from the Jena AB inbred strain differ in behavior from each other by their aggressiveness occurring especially in the latter group after maturity. In order to ascertain the neurobiological background of aggressiveness, we injected mice of both substrains with either haloperidol, diazepam, or hexobarbital and measured their response on motor activity. In a second experiment, the reaction to a seizure evoking agent (pentylenetetrazol) was determined.

Long-term potentiation and postconditioning potentiation--the same mechanism?

Stimulation of the perforant pathway with different stimulus pattern was used in freely moving rats to elicit classical posttetanic long-term potentiation (LTP), paired-pulse potentiation and postconditioning potentiation which appeared after using the perforant pathway stimulation as a conditioned stimulus in a shuttle-box learning paradigm. The changes in amplitude and latency of the population spike were compared. While in all experimental groups an amplitude potentiation of the population spike occurred, the changes in its latency were different.

Avoidance and brightness discrimination conditioning in genetically different lines of rats.

Rats from an albino stock were selected for high (HAS) and low (LAS) avoidance scores measured in a shuttle-box. Learning performance of male rats was compared in three different tests: the shuttle-box, the pole jumping-box, and the Y-chamber. It was shown that rats of the HAS line more rapidly acquired conditioned avoidance in the shuttle-box experiment and the pole-jumping experiment than LAS, whereas we could not detect any significant differences in brightness discrimination.