Search results for "STIMULATION"

Nigral control of hippocampal epilepsy: a dopaminergic hypothesis

1988

Vergleichende Untersuchungen �ber die Wirkung verschiedener Digitoxigeninderivate auf die Kontraktionskraft und den Ca-Austausch isolierter Meerschwe…

1963

An isolierten, elektrisch gereizten Meerschweinchenvorhofen wurde das Verhalten der Kontraktionskraft und des cellularen Ca-Haushaltesunter dem Einflus von Digitoxigenin, Dihydrodigitoxigenin und 3α-Digitoxigenin uber einen weiten Dosierungsbereich vergleichend untersucht. Diese Substanzen zeigten betrachtliche Unterschiede in der Intensitat ihrer positiv inotropen und kontrakturerzeugenden Wirkung. Im positiv inotropen Dosierungsbereich verhielten sich die aquieffektiven Konzentrationen von Digitoxigenin, Dihydrodigitoxigenin und 3α-Digitoxigenin etwa wie 1:20:70. Bei der Messung des transmembranen Ca-Austausches mit 47Ca ergab sich unter Kontrollbedingungen eine nur partielle Markierbarke…

Involvement of phospholipid metabolism in the events of the oxidative burst of granulocytes

1984

In summary we provide now evidence for specific interactions between the phospholipid metabolism and the oxidative burst. Lysophosphatidylcholine-like molecules showed specific enhancement of the oxidative burst and the capacity to replace phospholipase A2 function. Our findings might be useful in further studying the events occurring on the way from receptor stimulation to activation of the oxidative burst.

Effects of rewarding electrical stimulation of lateral hypothalamus on classical conditioning of the nictitating membrane response.

1997

1. Adult New Zealand albino rabbits were prepared with chronic hypothalamic stimulating electrodes and hippocampal recording electrodes. 2. Rabbits were restrained and classically conditioned by a tone CS and an airpuff US either followed or preceded by a hypothalamic stimulation (HS). Control rabbits were conditioned without the HS. 3. It was found that HS following the CS facilitated both behavioral and hippocampal responses, while HS preceding the CS inhibited them. 4. Enhanced hippocampal learning-related unit firing to the CS may represent an early indication of conditioning before the behavioral activity produces any observable change.

The dopamine D3 antagonist U-99194A maleate increases social behaviors of isolation-induced aggressive male mice.

1999

Rationale: Blockade of D1/D2 dopamine receptors produce an antiaggressive action commonly associated with an impairment of other motor behaviors. The D3 receptor seems to present opposite actions to the D1 and D2, since the blockade of this receptor produces stimulation of motor activity which has been associated with an increase in dopamine neurotransmission. Objective: In this work, the action of the dopamine D3 antagonist U-99194a maleate on locomotor activity and in a social interaction test in male mice was evaluated. Methods: Animals isolated during 30 days were treated with U-99194a maleate (20–40 mg/kg) or saline and locomotor activity was measured 20 min after drug administration. …

Influence of the suspension of continued treatment with flurazepam and amobarbital on two discrimination learning schedules.

1977

The authors have studied the effect of the suspension of chronic treatment with flurazepam and amobarbital on the operant behavior of rats that for the first time were in the presence of two fixed-interval discrimination schedules. With the sound discrimination schedule, the responses emitted by the treated animals had characteristics similar to those of control animals. With the temporal discrimination schedule, though it is not possible to distinguish between learning rates, modifications in the intensity of the effect (increases in lever pressing) indicate that, considering the doses, the action of flurazepam is slight and that of amobarbital clear and statistically significant.

The variation of acetylcholine release from myenteric neurones with stimulation frequency and train length. Role of presynaptic muscarine receptors.

1983

1. The effects of scopolamine on the release of 3H-acetylcholine (ACh) from the guinea-pig myenteric plexus were studied at different stimulation frequencies (0.03–10 Hz) and train lengths (1–180 pulses). Release of 3H-ACh was measured in the absence of cholinesterase inhibitors as the outflow of tritium from myenteric plexus-longitudinal muscle preparations preloaded with 3H-choline. 2. In control experiments the volley output of 3H-ACh declined with increasing train length and increasing stimulation frequency. Stimulation by one pulse produced the highest volley output. 3. Scopolamine facilitated the evoked output of 3H-ACh via blockade of presynaptic muscarine receptors. A significant in…

Neurotransmitters involved in the habenular control of raphe-hippocampal circuit

1989

Über das Wesen der optomotorischen Reaktionen

1953

Flying and swimming animals need to be able to avoid passive displacement by air and water currents. Optomotor reactions essentially serve this purpose. The animals must be able to distinguish precisely between sensory stimulation caused by passive displacement and by active locomotion. Stimulation due to active movements does not release optomotor reactions. Apparent exceptions to this rule, occurring only under artificial circumstances, are caused by a derangement of either normal sensory stimulation or normal movement and, consequently, of their normal correlation. Examples of both cases are discussed.

Time course of excitatory and inhibitory states of bulbar respiratory modulated neurons.

1980

In respiratory modulated neurons of rabbits, vagally mediated inhibition is not bound to resting membrane potential oscillations. Latency of spinally evoked antidromical spike invasion, however, is shorter and threshold voltage is lower during the shift of membrane potential towards depolarization accompanying burst discharge.