Slow potential changes in cat brain during classical appetitive conditioning of jaw movements using two levels of reward

Scalp recorded direct current potential shifts associated with quenching thirst in humans

“…In humans, slow negative potential shifts, such as the Bereitschaftspotential preceding voluntary movements and the contingent negative variation preceding expected imperative signals, have been demonstrated to increase in magnitude with increasing drive and reinforcement of the target behavior~e.g., Klorman & Rayn, 1980;McAdam & Seales, 1969;Rebert et al, 1967;Yee & Miller, 1987!. Corresponding observations that the amplitude of the DC-potential shift during consumatory behavior is dependent on the level of motivation have been made also in several animal studies~Irwin & Rebert, 1970;Rowland, 1968;Steinmetz & Rebert, 1972!. In addition, Rowland~1968!…”

“…A participation of glial cells has been repeatedly suggested because of the ability of these cells to spatially buffer extracellular K ϩ released during periods of increased neuronal firing~Lux, Heinemann, & Dietzel, 1986!. Also, glial cells can directly respond to different neurotransmitters and neuropeptides with an increase in intracellular Ca 2ϩ concentration~e.g., Laming, 1989;Verkhratsky, Orkand, & Kettenmann, 1998!. In animals cortical DC-potential shifts during drinking and reward, as well as spontaneously occurring cortical slow potential shifts, have been found to coincide with similar shifts in various subcortical structures, where they appear to be most consistent in the hypothalamus~Aladjalova, 1964; Irwin & Rebert, 1970;Rebert & Irwin, 1969;Rowland, 1968!. Moreover, in rabbits slow DCpotential shifts were measured simultaneously in the hypothalamus and cerebral cortex, after hypothalamic stimulation.…”

“…Thus, the negative DC-potential shift extending into the intermittent breaks of drinking strongly argues against a mere muscular origin of this potential. It likewise excludes that this potential shift is a direct sequel of motor activation and behavior~see for a similar conclusion Irwin & Rebert, 1970;Steinmetz & Rebert, 1972!. In addition, body fluid changes subsequent to drinking, as well as associated changes in osmolality and serum concentrations of sodium and potassium, were considered as potential sources influencing DC-potential recordings via a direct action on brain tissues. None of these parameters displayed changes that could account for the shifts in the DC potential associated with drinking.…”

“…Moreover, in thirsty cats given liquid food, concurrent shifts in the direct current~DC! potential can be observed in recordings from the frontal cortex and lateral hypothalamus~Irwin & Rebert, 1970;Rebert, 1978!, although joint oscillatory shifts in the DC potential in neocortical and hypothalamic regions may arise also "spontaneously"~Aladjalova, 1964; Born, Whipple, & Stamm, 1982!. DC potentials recorded from the cortical surface are considered to be mainly of neuronal origin, although additional glial contributions cannot be ruled out~Birbaumer, Elbert, Canavan, & Rockstroh, 1990;Caspers, Speckmann, & Lehmenküler, 1984;Cowan, 1974;Elbert, 1993;Roitbak, 1993!. It has become established that negative DC-potential shifts result from a widespread synchronized depolarization of apical dendrites of cortical pyramidal cells, thereby enhancing excitability of these neurons.…”

Action of Lysine-Vasopressin on Human Electroencephalographic Activity

“…Therefore, the former are useful for assessing basic sensory functions and the fur ther, and precisely the N 1 component reflects mainly the early stage of information pro cessing and selective attention. All these po tentials appear altered in clinical disorders of the nervous system and in cognitive deficits [Squires et al, 1979;Starr, 1977], They are also modified by psychotropic drugs [Saletu, 1976] and Rebert, 1970;Low et al, 1966] or operant [Macar and Vitton, 1979]. It in creases with the degree of attention [Tecce, 1972] and motivation [Irwin et al, 1966a.…”