Sustained potential shifts in the toad tectum reflect prey-catching and avoidance behavior.

Sustained potential shifts (SPS) were recorded for 10 s from the surface of the optic tectum of toads presented with live prey and moving artificial prey stimuli. On the anterior tectal surface, a negative SPS was followed by a positive wave; the converse was true for the posterior tectum. Some animals were immobilized, and they exhibited a monophasic negative SPS in the anterior tectum and a positive wave in more posterior regions.

Dendritic and sustained shifts in potential to electrical stimulation of the anuran tectal surface.

1. Recordings of dendritic potentials and sustained potential shifts (SPS) were made from the brain of immobilised frogs during surface tectal electrical stimulation. 2.

Posttetanic potentiation of primary response and late negative wave in the somatosensory region of the cortex of the cat.

The experiments were carried out on cats under nembutal anesthesia. Stimulation of the ventroposterolateral nucleus of the thalamus or the white matter by a single stimulus elicited a primary response in the middle layers of the somatosensory cortex, and after it, a late negative wave, the duration of which reaches 40-70 msec. This potential does not have dipole reflection on the surface of the cortex and is apparently generated primarily by stellate cells.

[Negative change in the potential of the cat cerebral cortex after transcallosal stimulation].

The slow negativity (SN) evoked with rhythmic transcallosal stimulation in anesthetized cats is generated in the upper layers of the cortex. The amplitude and duration of SN increased after the application of tetraethylammonium solution to the surface of the cortex. The SN seems to reflect mainly the glial depolarization.

[Changes in the concentration of extracellular potassium in the cerebral cortex with different parameters of electrical stimulation].

In anesthetized cats, a recording macroelectrode, a K+-sensitive microelectrode and a stimulating electrode were placed on the surface of the suprasylvian gyrus. As the duration or intensity of stimulus increased, the amplitude of K+-potential reflecting the changes in the extracellular concentration of K+ ions (delta [K+]o) was augmented, while the half time of decay decreased. delta [K+]o also increased when the number of stimuli increased.