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To study the learning performance of pentylenetetrazol- and amygdala-kindled Wistar rats we used the following learning tests: short-term memory was tested in the response-to-change model, brightness discrimination was tested in a Y-chamber, and two-way active avoidance learning was tested in a shuttle-box. Short-term memory was not impaired by both(More)
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,(More)
Stimulation of the perforant path with impulse trains of 15 cps and 670 msec duration was used as a conditioned stimulus in a two-way shuttle box avoidance on rats. Field potentials in the dentate area evoked by test stimuli were measured after the training sessions until the 7th day. Foot-shock and unconditioned escape elicited only a transient slight(More)
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(More)
Transient prenatal vitamin D deficiency is considered a neurodevelopmental animal model in schizophrenia research. Vitamin D deficiency in female rats causes morphological, cellular and molecular changes in the brain and alters behaviour and nerve growth factors expression in their offspring. Prenatal depleted animals showed a significant impairment of(More)
The aim of the present study with rats was to show that electrical stimulation of a monosynaptic pathway, whose high plastic potency is well-known, can serve as a conditioned stimulus (CS) in a learning paradigm. Using chronic rats, stimulation of the perforant pathway, which activates the entorhinal cortex input to the dentate gyrus of the hippocampus, was(More)
Successful acquisition of active avoidance by rats with low frequency (15 cps) stimulation of the perforant path as a conditioning stimulus is correlated with a slowly developing long-term enhancement of perforant path-granular cell synapses. After selective destruction of granular cells of the stimulated side by unilateral microinjection of 1.6(More)
The contribution of glycoprotein synthesis to functional synaptic changes and to the formation of memory traces was investigated by autoradiographic determination of the incorporation of [3H]fucose into the hippocampal structures of rats. In the first experiment, the fucose incorporation was measured after induction of post-tetanic long-term potentiation(More)
Using a brigthness discrimination model in rats, the labeling of discrete hippocampus formation structures was studied after intraventricular application of [3H]-fucose. This substance was injected 5 min before training as well as 5 min, 3, 7 and 23 h after training, the pulse period lasting 120 min in all cases. A significantly training-related enhanced(More)
Beta-casomorphin (5) Tyr-Pro-Phe-Pro-Gly, a partial sequence of bovine beta-casein with moderate opioid properties and mu-receptor affinity, was modified by substituting for the natural L-amino acids their D-analogs, and D-pipecolic acid, as well as by amidation of the C-terminal. Substitution of D-Pro or D-pipecolic acid for L-Pro4 considerably increased(More)