Effects Of Self-stimulation Research Articles

Understanding cerebellum in vertebrate neuroethology: From sensing in sharks and electric fish to motor sequences in movement and birdsong.

The elaborate structure of the cerebellum has been long known, although its contribution to a remarkable diversity of behavior is only recently appreciated. Taking an evolutionary perspective, we consider the wider function of the cerebellum based on insight from the function of so-called cerebellum-like structures. Cerebellum-like structures cancel the effects of self-stimulation, a function that has been well characterized in both elasmobranch and weakly electric fish. This function depends on the implementation of an adaptive filter, which provides an input-output transformation modified by specific learning rules. We argue that the broad contribution of the cerebellum to behavior can be understood by thinking of the cerebellum as an array of adaptive filters that can be coopted to a wide range of tasks. Consistent with this, studies of mammalian cerebellum reveal operations characteristic of an adaptive filter, which we review here. We then describe a model for how a cerebellar adaptive filter architecture could interact with central pattern generators and sensory feedback to coordinate sequentially patterned behavior. Finally, we use the acquisition and production of complex vocal motor sequencing in birdsong as an example to explore how this model of cerebellar adaptive filter-central pattern generator interactions may contribute to other important domains of vertebrate neuroethology. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

A comparative study of the new xylarate germanium (IV) complexe with lithium (xygerm-1), lithium chloride and valproic acid to the amphetamine-enhanced self-stimulation reactions in rats

Aim. To estimate the effect of novel lythium bis(µ-xylarato)dihydrogermanate (IV) (Xygerm-1) on reinforcing properties of the lateral hypothalamus self-stimulation in rats compared to the reference drugs (lithium chloride and valproic acid) in rats with amphetamine-induced self-stimulation. Methods. To form a model of the brain self-stimulation, nichrome monopolar electrodes were implanted bilaterally in the lateral hypothalamic nucleus, followed by morphological control, and 7-10 days after the operation, the rats were trained to press a pedal for electrical stimulation of the brain. The effects of self-stimulation were assessed by analyzing the maximum rate of pedal pressing and the self-stimulation threshold. Study of the test compounds effects had been started when average self-stimulation threshold values varied by less than 10% for three consecutive sessions of the brain self-stimulation. Xygerm-1 (300-1800 mg/kg), valproic acid (30-300 mg/kg) and lithium chloride (25-200 mg/kg) were introduced as intraperitoneal injections to animals of the corresponding study groups (6 rats each). At the next stage of the experiment, effects of Xygerm-1, lithium chloride and valproic acid on amphetamine-induced (dose 0.5 mg/kg) brain self-stimulation reaction increase were studied at the same animal groups. Results. At the first stage of the experiment Xygerm-1 (1200 and 1800 mg/kg), lithium chloride (100 and 200 mg/kg) and valproic acid (300 mg/kg) had significantly increased self-stimulation threshold. High doses of Xygerm-1 and lithium chloride (1800 and 200 mg/kg correspondingly) had relevantly decreased the average self-stimulation rate. There was also a tendency for the average self-stimulation rate to decrease in animals administered valproic acid, though, not statistically significant. The use of Xygerm-1 and lithium chloride induced the dose-dependant self-stimulation threshold increase, decreased by the use of amphetamine sulfate. Rather high doses of Xygerm-1 and lithium chloride (1800 and 100 mg/kg correspondingly) had also blocked amphetamine-induced increase in pedal pressing rate. Studied doses of valproic acid did not altered the amphetamine-induced brain self-stimulation reaction increase. Conclusion. The novel compound bis(µ-xylarato)dihydrogermanate (IV) has a strong influence on behavior, in particular on the brain reward systems, which is similar to the action of lithium chloride and differs from the effect of valproic acid.

Influence of Self-Stimulation of the Parasympathetic Nervous System on Lymphocyte Function and DNA Repair Function in Family Caregivers

The purpose of this study was to determine the effect of self-stimulation of the parasympathetic nervous system on immune function and DNA repair function in family caregivers. Seven female family caregivers engaged in individually tailored stimulation of the parasympathetic nervous system in everyday life for 2 weeks. Although we observed effects on lymphocyte function and secretory immunoglobulin A concentration in saliva compared with the control period, there was no effect on DNA repair function.

Systemically administered oxytocin decreases methamphetamine activation of the subthalamic nucleus and accumbens core and stimulates oxytocinergic neurons in the hypothalamus

Recent preclinical evidence indicates that the neuropeptide oxytocin may have potential in the treatment of drug dependence and drug withdrawal. Oxytocin reduces methamphetamine self-administration, conditioned place preference and hyperactivity in rodents. However, it is unclear how oxytocin acts in the brain to produce such effects. The present study examined how patterns of neural activation produced by methamphetamine were modified by co-administered oxytocin. Male Sprague-Dawley rats were pretreated with either 2 mg/kg oxytocin (IP) or saline and then injected with either 2 mg/kg methamphetamine (IP) or saline. After injection, locomotor activity was measured for 80 minutes prior to perfusion. As in previous studies, co-administered oxytocin significantly reduced methamphetamine-induced behaviors. Strikingly, oxytocin significantly reduced methamphetamine-induced Fos expression in two regions of the basal ganglia: the subthalamic nucleus and the nucleus accumbens core. The subthalamic nucleus is of particular interest given emerging evidence for this structure in compulsive, addiction-relevant behaviors. When administered alone, oxytocin increased Fos expression in several regions, most notably in the oxytocin-synthesizing neurons of the supraoptic nucleus and paraventricular nucleus of the hypothalamus. This provides new evidence for central actions of peripheral oxytocin and suggests a self-stimulation effect of exogenous oxytocin on its own hypothalamic circuitry. Overall, these results give further insight into the way in which oxytocin might moderate compulsive behaviors and demonstrate the capacity of peripherally administered oxytocin to induce widespread central effects.

Physiological pH and Acidic Phospholipids Contribute to Substrate Specificity in Lipidation of Atg8

Yeast Atg8 and its mammalian homolog LC3 are ubiquitin-like proteins involved in autophagy, a primary pathway for degradation of cytosolic constituents in vacuoles/lysosomes. Whereas the lipid phosphatidylethanolamine (PE) was identified as the sole in vivo target of their conjugation reactions, in vitro studies showed that the same system can mediate the conjugation of these proteins with phosphatidylserine as efficiently as with PE. Here, we show that, in contrast to PE conjugation, the in vitro phosphatidylserine conjugation of Atg8 is markedly suppressed at physiological pH. Furthermore, the addition of acidic phospholipids to liposomes also results in the preferential formation of the Atg8-PE conjugate. We have successfully captured authentic thioester intermediates, allowing us to elucidate which step in the conjugation reaction is affected by these changes in pH and membrane lipid composition. We propose that these factors contribute to the selective formation of Atg8-PE in the cell.

Intracranial self-stimulation improves memory consolidation in rats with little training

Post-training intracranial electrical self-stimulation can improve learning and memory consolidation in rats. However, the molecular mechanisms involved are not known yet. Since previous paradigms of this kind of facilitation are relatively unsuitable to try a molecular approach, here we develop a single and short model of learning and memory facilitation by post-training self-stimulation that could make easier the research of its neural and molecular basis. Thus, three consecutive experiments were carried out to ascertain whether post-training self-stimulation is able to facilitate memory when learning consists of only a brief (5 trials) two-way active avoidance conditioning session. The results of Experiment 1 showed that it is actually possible, and that 48 h after the acquisition session is a very good time to observe the memory improvement. As a way to probe the retroactive effect of self-stimulation, in Experiment 2 we observed that the same self-stimulation treatment given to the subjects not post-training but 48 h before a single two-way active avoidance session does not improve the acquisition of conditioning. In Experiment 3, we showed that the SS facilitative effect observed 48 h after the acquisition session in Experiment 1 was still maintained one week later. We concluded that post-training intracranial self-stimulation can consistently improve memory consolidation even when little acquisition training is given to the animals in a single training session.

Extrahypothalamic corticoliberin receptors regulate the reinforcing effects of self-stimulation

Extrahypothalamic corticoliberin receptors regulate the reinforcing effects of self-stimulation

Teaching children with autism appropriate play in unsupervised environments using a self-management treatment package.

The present study used a self-management treatment package to teach 3 children with autism, who exhibited inappropriate play behaviors, to play appropriately in the absence of a treatment provider. After self-management training, generalization and maintenance of the behavior change were assessed. Because of the detrimental effects of self-stimulation (arm flapping, spinning toys, twirling, etc.) on learning, the relationship between self-stimulatory behaviors and appropriate play was measured. Results indicated that the children learned to exhibit appropriate play skills in unsupervised settings, appropriate play skills generalized to new settings, and 2 of the children maintained their gains at 1-month follow-up. In addition, self-stimulatory behaviors decreased as appropriate play increased. Treatment implications of these findings are discussed.

Differential effect of self-stimulation on dopamine release and metabolism in the rat medial frontal cortex, nucleus accumbens and striatum studied by in vivo microdialysis

Changes in the extracellular levels of dopamine (DA) and its metabolites in the dopaminergic terminal regions, the medial frontal cortex (MFC), nucleus accumbens (NAC), and striatum (STR), were measured by microdialysis during self-stimulation of the medial forebrain bundle (MFB) in rats pretreated with the DA uptake inhibitor, nomifensine (1 mg/kg, i.p.).Self-stimulation of the MFB in nomifensine-pretreated rats caused an increase in the extracellular DA level in the MFC and NAC but not in the STR. Self-stimulation also increased the extracellular concentrations of the main DA metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) to a similar extent in the MFC and NAC and to a lesser extent in the STR. Thus, there was a regional difference in the neurochemical changes following self-stimulation with either the MFC or the NAC showing larger extracellular levels of DA, DOPAC, and HVA than the STR. Furthermore, these changes were observed on both hemispheres ipsilateral and contralateral to the stimulation. The results indicate that self-stimulation of the MFB preferentially activates the mesocorticolimbic DA systems, thereby bilateral increases in the release of DA and its metabolism being produced in their terminal regions, the MFC and NAC.

Effects of chronic electrode implantation on dopaminergic neurons in vivo

The present study evaluated the effects of chronic electrode implantation on stimulus-dependent increases of the dopamine (DA) metabolite dihydroxyphenylacetic acid (DOPAC) in relationship to a well characterized in vivo model which used electrical stimulation from acute electrode placements in the nigro-striatal pathway. Five days after bipolar electrodes were implanted into the nigro-striatal pathway, non-contingent electrical stimulation (100 μA, 25 Hz, 1.5 msec duration, 20 min session) did not change DA or DOPAC concentrations in the caudate nucleus, nucleus accumbens, or olfactory tubercles, whereas the same stimulation from acute electrode placements causes significant ipsilateral increases in caudate DOPAC. Although DOPAC concentrations did not change when these chronically implanted electrodes were stimulated, similar chronic electrode placement supported intracranial self-stimulation (ICSS). In order to examine the effects of self-stimulation on DOPAC concentrations, five ICSS test groups were established for comparison: implanted only, trained only, minimum response rate, 50% maximum response rate and maximum response rrate. Following a 50 min test session, a comparison of either DA, or DOPAC concentrations across the different ICSS conditions revealed no change for the caudate nucleus, nucleus accumbens or olfactory tubercles. Likewise, there was no change between the stimulated and unstimulated sides within each ICSS group. When a comparison was made between implanted only and maximal ICSS response rate groups for changes in DA or DOPAC concentrations in the frontal cortex, no differences were found. Apparently, chronic electrode implantation abolished the ability to electrically stimulate nigro-striatal dopaminergic neurons under non-contingent conditions, and the relationship between dopaminergic neurons and ICSS appears to be indirect in nature.

Learning and self-stimulation in mute and echolalic autistic children.

The effects of self-stimulation on task acquisition were studied in three mute low-functioning autistic and three echolalic higher-functioning autistic children in multiple-baseline designs. The study found that (a) the echolalic children were able to learn the task without external suppression of their self-stimulation and (b) the mute children were unable to learn the task until their self-stimulation was externally suppressed. It was suggested that the echolalic children may have acquired the ability to discriminate when to self-stimulate, so that their self-stimulation does not interfere with correct responding.

Action of naloxone on emotionally positive and antinociceptive effects of hypothalamic stimulation in rats

Naloxone (5 mg/kg subcutaneously) failed to effect significantly the reaction of electric self-stimulation in rats with electrodes implanted into lateral hypothalamic area. In 3 rats the analgesic effect manifested in an increase of the threshold of painful vocalization under electrostimulation of the tail was revealed. The antinociceptive effect was abolished with naloxone. Morphine (3 mg/kg) potentiated self-stimulation while naloxone antagonized this action. The role of opiate receptors in effects of self-stimulation and centrally produced analgesia is discussed.

The effects of self-stimulation on the catecholamine concentration of discrete areas of the rat brain

The effects of self-stimulation on the catecholamine concentration of discrete areas of the rat brain

Autonomic effects of hypothalamic self-stimulation in the cat

Respiration, heart rate and arterial blood pressure were recorded continuously during self-stimulation with systematically varied stimulus parameters. Conspicuous autonomic effects were induced by self-stimulation. Acceleration in the respiration and heart rate, and rise in the arterial blood pressure were generally obtained as direct effects of the stimulus train, which were followed by remarkable rebound-like aftereffects. A close relationship was found between the lever-pressing behaviour and the peripheral autonomic effects of self-stimulation. The frequency of self-stimulation increased in parellel with the amplitude of the autonomic responses to a certain level, and the animal stopped self-stimulation whenever the amplitude of the autonomic effects exceeded this level. The results are consistent with the idea that the peripheral autonomic changes can modulate self-stimulation.

Autonomic effects of hypothalamic self-stimulation in the cat.

Respiration, heart rate and arterial blood pressure were recorded continuously during self-stimulation with systematically varied stimulus parameters. Conspicuous autonomic effects were induced by self-stimulation. Acceleration in the respiration and heart rate, and rise in the arterial blood pressure were generally obtained as direct effects of the stimulus train, which were followed by remarkable rebound-like aftereffects. A close relationship was found between the lever-pressing behaviour and the peripheral autonomic effects of self-stimulation. The frequency of self-stimulation increased in parellel with the amplitude of the autonomic responses to a certain level, and the animal stopped self-stimulation whenever the amplitude of the autonomic effects exceeded this level. The results are consistent with the idea that the periopheral autonomic changes can modulate self-stimulation.

Self-stimulation and catecholamines. 3. Effect of imposed or self-stimulation in the area ventralis tegmenti on catecholamine utilization in the rat brain.

Changes in NE or DA utilization were estimated in various structures of the rat brain after imposed or self-stimulation of the area ventralis tegmenti. In the first two experiments, rats were implanted bilaterally with electrodes and were stimulated with current characteristics similar to those used during self-stimulation in previous training sessions. The imposed stimulation was applied for 1 h, either 1 h after α-methyl-p-tyrosine (α-MpT) injection (150 mg/kg i.p.) or immediately after bis(1-methyl-4-homopiperazinyl-thiocarbonyl disulfide) (FLA-63) (40 mg/kg i.p.). NE utilization was accelerated significantly in both experiments in the brain stem, hypothalamus, hippocampus and cortex. DA utilization in the striatum was not accelerated by imposed stimulation in α-MpT-treated rats. In the third experiment, the effect of self-stimulation on [ 3 H]CA utilization was directly examined by measuring the rate of disappearance of the 3 H-amines after labeling of CA stores. [ 3 H]DA was introduced through a chronic cannula implanted in the cisterna magna, and rats were allowed to self-stimulate bilaterally 5 min later for 1 h. Self-stimulation accelerated the utilization of [ 3 H]DA in the tuberculum olfactorium but also in the hypothalamus and the hippocampus. [ 3 H]DA levels were not significantly changed in either the brain stem or in the cortex. [ 3 H]NE utilization as well as NE turnover were markedly enhanced in the brain stem, hypothalamus, hippocampus and cortex. Imposed or self-stimulation of the area ventralis tegmenti activated the utilization and turnover of NE in structures innervated by both the ventral and dorsal ascending noradrenergic pathways. Dorsal noradrenergic neurons are probably activated by an interneuronal mechanism. The dopamine limbic system also appeared to be directly activated by self-stimulation. The respective role of noradrenergic and dopaminergic neurons in self-stimulation of the area ventralis tegmenti is discussed.

Self-stimulation alters human sensory brain responses.

Human electrocortical potentials evoked by self-administered auditory and visual stimuli manifest much smaller amplitude and faster poststimulus timing than do average brain responses evoked by identical machine-delivered stimuli. Auditory evoked potentials show this "self-stimulation effect" to a greater degree than do visual responses. For visual evoked potentials, the effect appears greater at the vertex association area than over the occipital cortex. Individual differences in the magnitude of the "self-stimutlation effect" relate to level of intelligence.

Resonant Interaction between Two Neutral Atoms

A standard formalism of quantum electrodynamics is used to investigate the interaction between two neutral atoms. The study is based on an approximate solution of the two-particle Green's function. The frequency distribution of the photon scattering is obtained. We also consider the self-stimulation effect when both atoms are in excited states.

Neurobehavioral development and the genotype-environment interaction.

Several research areas, notably those of psychology, physiology, and ethology, are reviewed in order to construct an interdisciplinary picture of problems and concepts pertaining to neurobehavioral development. Genetic factors, pre- and post-natal experiences and environmental influences which may affect ontogeny and modify the behavioral phenotype are reviewed. Development is considered as a series or continuum of genotype-environment interactions, and the effects of self-stimulation, experiential deprivation, enrichment, and handling are discussed. Ontogenetic phenomena, such as heterochronous patterning, induction and canalization, socialization, exploration and motivation, and the relationship between ontogeny and phylogeny of behavior are detailed to exposes the dynamic and intrinsic complexities of neurobehavioral development and of the genotype-environment interaction.

Hippocampal electrical correlates of self-stimulation in the rat

1. 1. Behavioral and EEG changes in response to electrical stimulation of several subcortical structures in rat's brain were studied. Motivational effects of self-stimulation were also examined together with EEG recordings. 2. 2. Three types of hippocampal electrical response (synchronization, depression and regular fast waves) were elicited in relation with orienting behavior, arrest reaction and violent vocalization respectively. 3. 3. Electrical stimulation which could motivate self-stimulation, in most cases induced regular fast waves, and in others depression in the hippocampus. Electrical stimulation which produced hippocampal synchronization did not induced self-stimulation. 4. 4. Self-stimulation accompanied by hippocampal fast waves was obtained at lateral hypothalamic, lateral pre-optic and ventral septal electrode positions, and was characterized by a high rate of pedal pressings, a relatively high threshold for self-stimulation, a short duration of each pedal press and by violent vocalization. Self-stimulation accompanied by hippocampal depression was obtained at dorsal septal electrode positions, and was characterized by a low response rate, a relatively low threshold, a long duration of pedal press and by a tendency toward seizure discharges. 5. 5. It is suggested that there might be a correlation between the motivationally positive effect and hippocampal desynchronization, but that no motivationally positive effects were demonstrable in relation to points evoking synchronous theta activity in the hippocampus.