Integrative physiological and behavioral science : the official journal of the Pavlovian Society最新文献

Nicotine enhances learning including contextual fear conditioning. The present study extends previous work on nicotine and conditioned fear to examine the nature of nicotine's enhancement of contextual fear conditioning and sex differences in contextual fear conditioning in C57BL/6 mice using a within-subjects design. Mice were trained by pairing of an auditory stimulus of 80 dB, 6 cps train of broad-band clicks conditioned stimulus (CS) with a 2 sec., 0.35 mA shock unconditioned stimulus (US). Twenty-four hours later mice were tested for freezing in the original context, and one hour later mice were retested in the same context. A 0.5 mg/kg dose of nicotine was given either for three conditions: (1) before training, testing, and retesting; (2) before training and retesting; and (3) before retesting only. The use of a within-subjects design allowed for testing if nicotine would produce state-dependent deficits in contextual fear conditioning. Nicotine did enhance contextual fear conditioning in the groups that received nicotine for both training and testing. Nicotine, however, did not alter freezing when given on training but not testing or testing but not training. No sex differences, however, existed for conditioning or for nicotine's effects on conditioning. These results suggest that nicotine enhanced acquisition and retrieval processes but did not produce state-dependent deficits when administered just for training or just for testing.

Pavlovian conditioning procedures, in which events such as tastes, lights, and sounds become predictors of food, water, and shocks, have been used for studying the role of the information filter in the selection of conditioned responses. Different models posit the filter at different locations in the S-R stream, but most models suggest either a pre-encoding filter, in which much information is discarded at an early stage of processing, or a post-encoding filter, in which the information is stored but not subsequently expressed in behavior. A selective review of the literature on cue-competition effects reveals a plethora of phenomena that support a post-encoding, but not a pre-encoding filter in Pavlovian processes.

Considerable evidence indicates that conditioned gaping in rats reflects nausea in this species that does not vomit. A series of experiments evaluated the potential of psychoactive cannabinoid agonists, delta-9-THC and HU-210, and non-psychoactive cannabinoids, Cannabidiol (CBD) and its dimethylheptyl homolog (CBD-dmh), to interfere with the establishment and the expression of conditioned gaping in rats. All agents attenuated both the establishment and the expression of conditioned gaping. Furthermore, the CB1 antagonist, SR-141716, reversed the suppressive effect of HU-210 on conditioned gaping. Finally, SR-141716 potentiated lithium-induced conditioned gaping, suggesting that the endogenous cannabinoid system plays a role in the control of nausea.

In the present experiments, we investigated the effects of several commonly employed antiepileptic drugs on the performance of adult rats in a Morris water maze task. We found that phenytoin treatment produced the most deleterious performance impairments across all days of training, and that these performance deficits are not likely due to any general sensorimotor impairments. Carbamazepine had milder, but detectable negative effects, as carbamazepine-treated animals exhibited initial acquisition deficits, but rapidly achieved escape levels comparable to controls. In marked contrast, valproate and ethosuximide had no detectable effects on learning in the water maze. These results parallel previous findings in rats treated with these compounds and tested in an instrumental learning task, and are in general agreement with the human clinical literature. To the extent that one might wish to minimize learning deficits associated with maintenance on antiepileptic drugs, phenytoin is definitely not the treatment of choice, while valproate or ethosuximide are apparently much less disruptive.

The differential outcomes effect--the enhancement of learning and memory performance by correlating distinct reinforcers with to-be-remembered events (sample stimuli)--has been stated to be one of the most robust phenomena in learning psychology. However, in this paper we demonstrate that the correlation between unique samples and unique reinforcers can either interfere with or enhance learning a spatial matching-rule, dependent on whether these two processes are trained concurrently or sequentially. If the Pavlovian conditioning (unique sample-reward pairings) occurs before the matching rule is learned (sequentially), the conditioned expectations of unique rewards will enhance the acquisition of the spatial matching-rule in rats (the differential outcomes effect will be observed). However, if rats are required to learn the Pavlovian associations and the matching-rule concurrently, they are impaired in acquiring the spatial matching-rule. Thus, employing the differential outcomes procedure can either enhance or detract from learning and remembering the task rule-dependent on the nature of the task and order of training. These data suggest that under some circumstances learning Pavlovian associations can compete with the formation of instrumental behavior.

Leverpress escape/avoidance is an excellent model for assessing coping in rats. Acquisition of the leverpress response is determined by the interstimulus (signal-shock) interval, as well as the type and duration of the aversive event. One factor that has received less research attention is the safety or feedback signal. The safety signal presumably negatively reinforces leverpress responding through fear reduction. Here, we present a parametric manipulation of safety signal length and avoidance performance. All rats were trained with a 60-s tone conditioned stimulus and an intermittent 1-s, 1.0-mA footshock. Training was further accomplished with a 1-, 2-, 4-, or 6-min safety signal. Acquisition of the avoidance response was comparable at all safety signal durations. Rats trained with the shortest safety signal (1 min) exhibited more leverpresses during the safe period, a measure of anxiety. Thus, acquisition of the leverpress avoidance response was efficient regardless of safety signal duration, even though shorter periods were associated with greater anxiety.

Exposure of the developing brain to alcohol produces profound Purkinje cell loss in the cerebellum, and deficits in tests of motor coordination. However, the precise relationship between these two sets of findings has been difficult to determine. Eyeblink classical conditioning is known to engage a discrete brainstem-cerebellar circuit, making it an ideal test of cerebellar functional integrity after developmental alcohol exposure. In eyeblink conditioning, one of the deep cerebellar nuclei, the interpositus nucleus, as well as specific Purkinje cell populations, are sites of convergence for CS and US information. A series of studies have shown that eyeblink conditioning is impaired in both weanling and adult rats given binge-like exposure to alcohol as neonates, and that these deficits can be traced, at least in part, to impaired activation of cerebellar interpositus nucleus neurons and to an overall reduction in the deep cerebellar nuclear cell population. Because particular cerebellar cell populations are utilized in well-defined ways during eyeblink conditioning, conclusions regarding specific changes in the mediation of behavior by these cell populations are greatly strengthened. Further studies will be directed towards the impact of early exposure to alcohol on the functionality of specific Purkinje cell populations, as well as towards brainstem areas that process the tone CS and the somatosensory US.

This paper offers an interpretation of the relation between Pavlov's life and work and the missions of the Pavlovian Society, both past ("observation and observation") and present ("interdisciplinary research on the integrated organism"). I begin with an account of Pavlov's life and his influence on contemporary thought. I then indicate the relation of some of Pavlov's attitudes (e.g., his motto, his epistemological stance) to the Society's past mission. In the concluding and most controversial section, I argue for six guiding principles derived from Pavlov, to be applied to the Society's mission. These are: (a) a confident methodological behaviorism; (b) a significant role assigned to both physiological and psychological factors in the prediction and control of the integrated organism; (c) approximately equal taxonomic precision of physiological and psychological explanatory concepts; (d) distrust of teleological explanatory concepts; (e) rejection of psychology's instrumentalist "cognitive paradigm shift"; and (f) rejection of the representational theory of knowledge.

Essentially all behavior is regulated by the brain in response to information received from within the body or from the environment. The tangible structures of the brain serve as devices for processing thoughts and emotions as well as information. Stored among the interacting neural structures are memories of past experiences and responses to them. These intangibles participate in determining the decisions made and the actions performed by the brain's structures. There are valuable studies of the clinical and neurological effects of environmental stimuli, but we need to learn more about the processes that lead to these effects. More definitive correlations could be made between environmental stimuli and the neurological pathways they create by studying individual's real life experiences rather than laboratory simulations alone.

This study explored the possible beneficial effects of singing on well-being during a singing lesson. Eight amateur (2m, 6f, age 28-53 yrs) and eight professional (4m, 4f, age 26-49 yrs) singers who had been attending singing lessons for at least six months were included. Continuous ECG was recorded and computerized spectral analysis was performed. Serum concentrations of TNF-alpha, prolactin, cortisol, and oxytocin were measured before and 30 min after the lesson. Five visual analogue scales (VAS, sad-joyful, anxious-calm, worried-elated, listless-energetic, and tense-relaxed) were scored before and after the lesson. In addition, a semi-structured interview was performed. Heart rate variability analyses showed significant changes over time in the two groups for total power, and low and high frequency power. Power increased during singing in professionals, whereas there were no changes in amateurs. This indicates an ability to retain more "heart-brain connection." i.e., more cardio-physiological fitness for singing in professional singers, compared to amateur singers. Serum concentration of TNF-alpha increased in professionals after the singing lesson, whereas the concentration in amateurs decreased. Serum concentrations of prolactin and cortisol increased after the lesson in the group of men and vice versa for women. Oxytocin concentrations increased significantly in both groups after the singing lesson. Amateurs reported increasing joy and elatedness (VAS), whereas professionals did not. However, both groups felt more energetic and relaxed after the singing lesson. The interviews showed that the professionals were clearly achievement-oriented, with focus on singing technique, vocal apparatus and body during the lesson. The amateurs used the singing lessons as a means of self-actualization and self-expression as a way to release emotional tensions. In summary, in this study, singing during a singing lesson seemed to promote more well-being and less arousal for amateurs compared to professional singers, who seemed to experience less well-being and more arousal.