Acquired equivalence and distinctiveness of cues: II. Neural manipulations and their implications

Neural manipulations were used to examine the mechanisms that underlie the acquired equivalence and distinctiveness of cues in rats. Control rats and those with excitotoxic lesions of either the hippocampus (HPC) or entorhinal cortex (EC) acquired the following conditional discrimination: In Contexts A and B, Stimulus X-->food and Stimulus Y-->no food, and in Contexts C and D, Y-->food and X-->no food. Rats then received many food pellets in A but not in C. After this treatment, control rats showed more magazine activity in B than in D--an acquired equivalence-distinctiveness effect. This effect was also evident in HPC rats but not in EC rats. These results indicate that changes in stimulus distinctiveness are dissociable from the process of conditional learning.

The influence of selective lesions to components of the hippocampal system on the orienting [correction of orientating] response, habituation and latent inhibition

The contribution that components of the hippocampal system in the rat make to the modulation of attention or stimulus processing was assessed using several simple behavioural assays: the orienting response (OR) to a novel stimulus, the subsequent habituation and dishabituation of this OR, and the latent inhibition effect that typically results from repeated exposure to a stimulus. Excitotoxic lesions of components of the hippocampal system produce dissociable effects on the OR, habituation and latent inhibition: lesions of the entorhinal cortex have no effect on the OR or changes in the OR during exposure to a stimulus, but disrupt latent inhibition; lesions of the subiculum disrupt the OR but not latent inhibition; and lesions of the hippocampus disrupt the OR and latent inhibition. These effects have important implications for our understanding of habituation and latent inhibition, and the neural mechanisms involved in attentional modulation.

Sensation and Distress of Pain Scales: reliability, validity, and sensitivity

Psychometric properties of the Sensation and Distress of Pain Visual Analogue Scales (VAS) are compared to dual numerical rating scales (NRS) with data from a randomized controlled trial of postoperative patients. On postoperative days 1 and 2, 15-minute test-retest reliability was .73 to .82 for the VAS and slightly lower for the NRS, r = .72 to .78, while convergent validity of the scales ranged from r = .90 to .92; construct validity of sensation and distress ranged from r = .72 to .85; and discriminant validity was lower, r = .65 to .78. Both instruments were significantly associated with pain reduction following treatment, p < .05 to .01. The VAS scores were significantly lower, p < .01 to .001, and more evenly distributed than NRS scores. It is recommended that the VAS be used in research to produce continuous scores that are more suited to parametric analysis.

Influence of a beacon on spatial learning based on the shape of the test environment

In 5 experiments rats were required to escape from a triangular shaped pool by swimming to a submerged platform. The principal group of interest in each experiment received training with a beacon attached to the platform. The purpose of the experiments was to assess if the beacon overshadowed (Experiments 1-4) or blocked (Experiment 5) learning about the position of the platform with reference to the shape of the pool. The platform was located in the center of the pool for the first 2 experiments and in a corner for the remaining experiments. Although there was an overshadowing effect in Experiment 1, the remaining experiments failed to reveal any disruptive influence of the beacon on learning based on the shape of the pool. Moreover, in Experiments 3-5 there was an indication that the beacon facilitated such learning. The results suggest that spatial learning based on the shape of a test environment may not take place in the same way as that based on more discrete landmarks.

Involvement of the entorhinal cortex in a process of attentional modulation: evidence from a novel variant of an IDS/EDS procedure

Novel behavioral assays were used to assess the role of the entorhinal cortex in modulating attention to components of stimulus compounds. In Stage 1, rats received discrimination training with compounds constructed from 3 dimensions (auditory, visual, and tactile); in each compound the combination of components from 2 dimensions (e.g., auditory and visual) were relevant to the solution of the discrimination, and the remaining dimension (e.g., tactile) was irrelevant. In Stage 2, rats received a different discrimination in which the relevant dimensions were either congruent (auditory and visual) or incongruent (auditory and tactile) with those that were relevant in Stage 1. Sham-operated rats acquired the congruent discrimination more rapidly than the incongruent discrimination--a finding indicative of a process of attentional modulation--whereas rats with excitotoxic lesions of the entorhinal cortex acquired both discriminations equally readily.

Excitotoxic lesions of the hippocampus leave sensory preconditioning intact: implications for models of hippocampal function

Learning about contextual cues is markedly disrupted in rats with hippocampal lesions. One analysis of this disruption is that it reflects a general failure to form associations between the elements of complex events. A straightforward prediction of this analysis is that sensory preconditioning will be disrupted by hippocampal lesions. This prediction was assessed by presenting rats with flavored solutions composed of 2 elements (A and X) before X was paired with an injection of the emetic, lithium chloride. A subsequent test revealed that rats were less willing to consume Solution A than they were to consume a control solution, B. This was true of rats with sham lesions and those with excitotoxic lesions of hippocampus. These findings fail to support the proposition that the hippocampus-dependent deficit in contextual conditioning is due to a general disruption to the process of associating the elements of complex events.

Influence of a beacon on spatial learning based on the shape of the test environment

In 5 experiments rats were required to escape from a triangular shaped pool by swimming to a submerged platform. The principal group of interest in each experiment received training with a beacon attached to the platform. The purpose of the experiments was to assess if the beacon overshadowed (Experiments 1-4) or blocked (Experiment 5) learning about the position of the platform with reference to the shape of the pool. The platform was located in the center of the pool for the first 2 experiments and in a corner for the remaining experiments. Although there was an overshadowing effect in Experiment 1, the remaining experiments failed to reveal any disruptive influence of the beacon on learning based on the shape of the pool. Moreover, in Experiments 3-5 there was an indication that the beacon facilitated such learning. The results suggest that spatial learning based on the shape of a test environment may not take place in the same way as that based on more discrete landmarks.

Involvement of the entorhinal cortex in a process of attentional modulation: evidence from a novel variant of an IDS/EDS procedure

Novel behavioral assays were used to assess the role of the entorhinal cortex in modulating attention to components of stimulus compounds. In Stage 1, rats received discrimination training with compounds constructed from 3 dimensions (auditory, visual, and tactile); in each compound the combination of components from 2 dimensions (e.g., auditory and visual) were relevant to the solution of the discrimination, and the remaining dimension (e.g., tactile) was irrelevant. In Stage 2, rats received a different discrimination in which the relevant dimensions were either congruent (auditory and visual) or incongruent (auditory and tactile) with those that were relevant in Stage 1. Sham-operated rats acquired the congruent discrimination more rapidly than the incongruent discrimination--a finding indicative of a process of attentional modulation--whereas rats with excitotoxic lesions of the entorhinal cortex acquired both discriminations equally readily.

Identifying cortical inputs to the rat hippocampus that subserve allocentric spatial processes: a simple problem with a complex answer

A consideration of the cortical projections to the hippocampus provides a number of candidate regions that might provide distal sensory information needed for allocentric processing. Prominent among the input regions are the entorhinal cortex, the perirhinal cortex, the postrhinal cortex, and the retrosplenial cortex. A review of these sites reveals the surprising fact that in spite of their anatomical connections, removal of the perirhinal and postrhinal cortices has little or no effect on spatial tasks and hence does not functionally disconnect the hippocampus. Extensive retrosplenial lesions have only mild effects, and even lesions of the entorhinal cortex only partially mimic the effects of hippocampal lesions upon tests of spatial memory. In contrast, studies using c-fos imaging support the involvement of the entorhinal, postrhinal, and retrosplenial cortices, but not the perirhinal cortex. It is argued that there exist multiple aspects of spatial memory, and this is reflected in the multiple routes by which cortical information can reach the hippocampus. One consequence is that lesions in a single site often have surprisingly mild effects on standard spatial tests.

Relaxation and music to reduce postsurgical pain

AIMS

We investigated the effects of relaxation, music, and the combination of relaxation and music on postoperative pain, across and between two days and two activities (ambulation and rest) and across ambulation each day. This secondary analysis of a randomized controlled trial was conducted from 1995 to 1997.

BACKGROUND

After surgery, patients do not always receive sufficient relief from opioids and may have undesired side-effects. More complete relief (10-30%) was found recently with adjuvant interventions of relaxation, music, and their combination. Comparison of effects between days and treatments have not been examined longitudinally.

METHODS

With a repeated measures design, abdominal surgery patients (n = 468) in five US hospitals were assigned randomly to one of four groups; relaxation, music, their combination, and control. With institutional approval and written informed consent, subjects were interviewed and taught interventions preoperatively. Postoperative testing was at ambulation and rest on days 1 and 2 using visual analogue (VAS) sensation and distress of pain scales.

RESULTS

Multivariate analysis indicated that although pain decreased by day 2, interventions were not different between days and activities. They were effective for pain across ambulation on each day, across ambulation and across rest over both days (all P < 0.001), and had similar effects by day and by activity.

CONCLUSION

Nurses can safely recommend any of these interventions for pain on both postoperative days and at both ambulation and rest.

Pain outcomes after intestinal surgery

Pain sensation and distress in 38 intestinal surgical patients were moderate to severe on postoperative day 1, ranging from 34 to 49 mm and 33 to 45 mm, respectively, on 100-mm scales. During ambulation, both increased from baseline to post-ambulation, P < 0.01. Half of the patients reported severe pain not relieved by analgesics, and although 44% learned a relaxation technique in the past, only 8% used one for pain after this surgery. Pain disturbed the sleep of 34% of the patients, and pain was related to respiratory, intestinal, febrile, and other complications in 18 (47%) subjects. Attentive analgesic use and nonpharmacologic therapies are recommended.

The lived experience of listening to music while recovering from surgery

Music has been shown to have positive physiological and psychological effects on patients in previous studies. In this study, the authors looked at the lived experience of listening to music and evaluated findings from a phenomenological perspective. Specifically, the authors described the following three themes that emerged from interview data with 8 participants who listened to music during postoperative recovery: (a) comfort from a discomforting condition, (b) familiarity in a strange environment, and (c) distraction from fear, pain, and anxiety. In addition, implications for the use of music by nurses are discussed.

Cultural differences in music chosen for pain relief

Nurses use music therapeutically but often assume that all patients will equally appreciate the same type of music. Cultural differences in music preferences are compared across five pain studies. Music preferences for pain relief are described as the most frequently chosen type of music for each culture. Findings indicate that in four studies, musical choices were related to cultural background (p = .002 to .049). Although the majority in each group chose among the other types of music, Caucasians most frequently chose orchestra music, African Americans chose jazz, and Taiwanese chose harp music. For culturally congruent care, nurses should become aware of cultural differences in music preference and provide culturally specific selections among other music expected to have a therapeutic effect.

Pain after gynecologic surgery

This article provides a descriptive profile of pain in 80 women during the first 2 days after gynecologic surgery in 4 hospitals. Surgical procedures included abdominal hysterectomy, oophorectomy, and laparotomy. Average pain was moderate on both days, but paired t tests indicated that pain increased significantly during ambulation on day 1 (P = .009, sensation; P < .001, distress) and on day 2 (P = .007, sensation; P = .030, distress). They both (P = .001) decreased significantly during rest on day 1, but not on day 2. Analysis of quartiles indicated that one fourth of the sample suffered severe sensation pain at all points on day 1 (60 to 74 mm on a 100-mm visual analogue scale), and moderate to severe sensation on day 2 (40 to 60 mm). The lowest quartile had mild pain on both days (11 to 28 mm on day 1, and 7 to 14 mm on day 2). Some patients (30%) reported that pain interrupted their sleep on the first 2 nights, and difficulty sleeping on the first postoperative night for any reason (65%) was related to greater pain during the next 2 days (r = .25 to .43). Although 41% of the women had previously used relaxation techniques for stress or pain, only 9% used it for pain after surgery. Results suggest that postoperative patients have moderate to severe pain that is incompletely relieved with patient-controlled analgesia. Nurses should encourage patients to press the patient-controlled analgesia button more often, report unrelieved pain, and use nonpharmacologic interventions.

The effects of combined lesions of the subicular complex and the entorhinal cortex on two forms of spatial navigation in the water maze

The role of the subicular complex and entorhinal cortex (SUB-EC) in spatial learning was examined in 2 water maze experiments. In Experiment 1, rats had to locate a hidden platform that was always a fixed distance and direction from an intramaze landmark. Each day, the landmark and platform were moved to a new location. Both control and SUB-EC-lesioned rats learned to locate the platform equally readily during training. However, the control group was impaired in locating the platform when the visual extramaze cues were concealed, whereas the lesioned group was unaffected by this manipulation. In Experiment 2, the lesioned rats were impaired in finding a hidden platform that was in a fixed place in the water maze and showed no evidence of having learned its location in a probe test. These results suggest that damage to the SUB-EC impairs the integration of geometric information but spares a more general navigational-directional strategy.

Associative components of recognition memory

Recent results indicate that visual recognition memory (as assessed by habituation and dishabituation of the orienting response) is influenced by associative knowledge, and that this influence is mediated by the hippocampus. A standard, associative model of learning has been recently reported to provide a parsimonious explanation for these results.

The effects of combined lesions of the subicular complex and the entorhinal cortex on two forms of spatial navigation in the water maze

The role of the subicular complex and entorhinal cortex (SUB-EC) in spatial learning was examined in 2 water maze experiments. In Experiment 1, rats had to locate a hidden platform that was always a fixed distance and direction from an intramaze landmark. Each day, the landmark and platform were moved to a new location. Both control and SUB-EC-lesioned rats learned to locate the platform equally readily during training. However, the control group was impaired in locating the platform when the visual extramaze cues were concealed, whereas the lesioned group was unaffected by this manipulation. In Experiment 2, the lesioned rats were impaired in finding a hidden platform that was in a fixed place in the water maze and showed no evidence of having learned its location in a probe test. These results suggest that damage to the SUB-EC impairs the integration of geometric information but spares a more general navigational-directional strategy.

Associative modulation of the orienting response: distinct effects revealed by hippocampal lesions

The ability of auditory stimuli to modulate rats' tendency to orient to visual targets was assessed. In Experiment 1, trials where an auditory stimulus (A) signaled one visual array (X) were intermixed with unsignaled presentations of a second array (Y). Comparison of the orienting responses (ORs) to X and Y revealed that A produced a transient (unconditioned) and an emerging (conditioned) disruptive influence on the OR to X. In Experiments 2 and 3, trials where A signaled X were intermixed with others where another auditory stimulus (B) signaled Y. Stimulus A's ability to modulate the OR to X was then assessed by presenting A prior to test arrays containing both X and Y. Control rats were more likely to orient to Y than X (Experiments 2 and 3) and rats with excitotoxic lesions of the hippocampus were more likely to orient to X than Y (Experiment 3). These results show that auditory stimuli exert distinct modulatory influences on the OR to visual stimuli with which they are associated.

Cyclical changes in endogenous levels of oestrogen modulate the induction of LTD and LTP in the hippocampal CA1 region

The present study investigated the effects of naturally fluctuating endogenous levels of oestrogen on the induction and maintenance of long-term potentiation (LTP) and long-term depression (LTD) in the CA1 region of the hippocampus. Using an anaesthetized in vivo preparation, the results showed that the induction of LTP was augmented during the pro-oestrous stage of the oestrous cycle. In contrast to LTP, however, the induction of paired-pulse LTD was severely attenuated during pro-oestrous, but was clearly manifested by rats during met/dioestrous and oestrous stages of the cycle. These findings are discussed with reference to: (i) the modulatory effects of oestrogen on N-methyl-D-aspartate (NMDA) receptor function and gamma-aminobutyric acid (GABA) neurotransmission in the hippocampus; and (ii) the functional implications that such cyclical changes in synaptic plasticity have for learning and memory processes supported by the hippocampus.

Acute pain

The review of acute pain describes the problem of unresolved pain and its effects on the neural, autonomic, and immune systems. Conceptualizations and mechanisms of pain are reviewed as well as theories of pain management. Descriptive studies of patient and nurse factors that inhibit effective pain management are discussed, followed by studies of pharmacological and nonpharmacological interventions. Critical analysis reveals that most studies were atheoretical, and therefore, this proliferation of information lacked conceptual coherence and organization. Furthermore, the nature and extent of barriers to pain management were described, but few intervention studies have been devised, as yet, to modify the knowledge, beliefs, and attitudes of nurses and patients that are barriers to pain management. Although some of the complementary therapies have sufficient research support to be used in clinical pain management, the physiological mechanisms and outcomes need to be studied. It is critical at this time to design studies of interventions to improve assessment, decision making, attentive care, and patient teaching.

Relief of postoperative pain with jaw relaxation, music and their combination

The aim of this randomized controlled trial was to determine the effect of jaw relaxation, music and the combination of relaxation and music on postoperative pain after major abdominal surgery during ambulation and rest on postoperative days 1 and 2. Opioid medication provided for pain, following abdominal surgery, does not always give sufficient relief and can cause undesired side effects. Thus, additional interventions such as music and relaxation may provide more complete relief. Previous studies have found mixed results due to small sample sizes and other methodological problems. In a rigorous experimental design, 500 subjects aged 18-70 in five Midwestern hospitals were randomly assigned by minimization to a relaxation, music, relaxation plus music, or control group. Interventions were taught preoperatively and tested postoperatively. The same amount of time was spent with subjects in the control group. Pain was measured with the visual analogue sensation and distress of pain scales. Demographic and surgical variables, and milligrams of parenteral or oral opioids in effect at the time of testing were not significantly different between the groups, nor did they correlate with pain scores. Controlling for pretest sensation and distress, orthogonal a priori contrasts and multivariate analysis of covariance indicated that the three treatment groups had significantly less pain than the controls, (P = 0.028-0.000) which was confirmed by the univariate analysis of covariance (P = 0.018-0.000). Post hoc multivariate analysis revealed that the combination group had significantly less sensation and distress of pain than the control group on all post-tests (P = 0.035-0.000), and the relaxation and music groups had significantly less on all tests (P = 0.022-0.000) except after ambulation. At post ambulation those using relaxation did not have significantly less pain than the controls on both days and those using music did not on day 1, although there were some univariate effects. A corresponding significant decrease in mastery of the interventions from pre to post ambulation suggests the need for reminders to focus on the intervention during this increased activity. Physicians and nurses preparing patients for surgery and caring for them afterward, should encourage patients to use relaxation and music as adjuvants to medication for postoperative pain.

Hippocampal lesions disrupt navigation based on cognitive maps but not heading vectors

Animals can find a hidden goal in several ways. They might use a cognitive map that encodes information about the geometric relationship between the goal and two or more landmarks. Alternatively, they might use a heading vector that specifies the direction and distance of the goal from a single landmark. Rats with damage to the hippocampus have difficulty in finding a hidden goal. Here we determine which of the above strategies is affected by such damage. Rats were required to swim in a water maze to a submerged platform, which was always at the same distance and direction from a landmark. The platform and landmark remained in the same place for the four trials of each session, but they were moved to a new position at the start of a session. Rats with damage to the hippocampus found the platform more efficiently than did normal rats in the first trial of a session but, in contrast to normal rats, their performance did not improve during a session. Our results indicate that hippocampally damaged rats are able to navigate by means of heading vectors but not cognitive maps.

Contingent versus incidental context processing during conditioning: dissociation after excitotoxic hippocampal plus dentate gyrus lesions

This experiment explored whether excitotoxic hippocampus plus dentate gyrus (HPC/DG) lesions in rats would dissociate the differential processing of contextual cues during the performance of learned associations when (1) their processing during training is incidental to successful learning or (2) the solution of a discrimination problem is contingent on their processing. A series of training stages were conducted, beginning with appetitive conditioning to two stimuli (X and Y), each of which was trained in one of two different contexts (operant chambers A and B) (i.e., AX+, BY+). Conditioning was indexed as appetitive responding. The animals were then trained on a biconditional contextual discrimination with these same stimuli (AX+, AY-; BY+, BX-). The next stage involved conditioning trials to two new stimuli (W and Z), one in each context, while the animals were actively discriminating contexts A and B by continuing to perform the original biconditional discrimination (AX+, AY-, AW+; BY+, BX-, BZ+). Finally, they were trained on a second biconditional discrimination involving these new stimuli (AX+, AY-, AW+, AZ-; BY+, BX-, BZ+, BW-). The incidental use of context cues was examined by looking at the rate of conditioned responding to cues X, Y, W, and Z in their original training contexts or a different context; HPC/DG lesioned rats differed from controls in being unaffected by a change of context. The contingent use of context cues was examined by looking at performance of each of the two biconditional tasks; HPC/DG lesioned rats reached levels of conditional performance indistinguishable from those of controls. These findings point to two distinct ways in which contextual information is processed in the brain, revealing a dissociation between incidental and contingent processing of contextual cues after HPC/DG lesions.

Differential effects of ibotenic acid lesions of the hippocampus and blockade of N-methyl-D-aspartate receptor-dependent long-term potentiation on contextual processing in rats

The contextual specificity of appetitive conditioned responding was examined in rats undergoing chronic intracerebroventricular infusion of 15 or 30 mM D-2-amino-5-phosphonopentanoic acid (D-AP5) or with excitotoxic hippocampal lesions. The magnitude of conditioned responding by control rats and rats infused with D-AP5 to a conditioned stimulus (CS) trained in Context A was attenuated when the same stimulus was presented in Context B. By contrast, hippocampal-lesioned rats displayed comparable levels of responding to the CS when presented in either Context A or B. Subsequent in vivo electrophysiological investigations showed that the D-AP5 concentrations were effective in blocking long-term potentiation (LTP) in the dentate gyrus. Results indicate that rats are capable of processing contextual information in the absence of N-methyl-D-aspartate (NMDA) receptor-dependent LTP and demonstrate an important dissociation between the effects of hippocampal lesions and the blockade of NMDA receptors in the hippocampus.

Hippocampal lesions disrupt an associative mismatch process

Novel assays were used to assess inter alia whether the hippocampus is involved in detecting novelty per se or in an associative mismatch process. During training, rats received two audiovisual sequences (tone-left constant light and click-left flashing light). In both sham-operated control rats and those with excitotoxic hippocampal lesions, novel visual targets provoked an orienting response that habituated during training. Moreover, like sham-operated rats, rats with hippocampal lesions acquired associations between the elements of two audiovisual sequences. However, subsequent test trials in which the auditory stimuli preceding the visual targets were switched (click-left constant light and tone-left flashing light) provoked renewed orienting to the visual targets in sham-operated rats but not in hippocampal rats. These results support the view that hippocampal damage results in a failure to detect (or act on) mismatches that are generated when an auditory stimulus associatively evokes the memory of one visual stimulus and a different (familiar) visual stimulus is present in the environment.

The effects of Western music on postoperative pain in Taiwan

Music is a method nurses can use to help relieve pain, however little is known about its effectiveness across cultures. In this study, Western music was tested for its effectiveness in reducing postoperative pain in 38 Taiwanese patients, and its acceptability was explored. A pretest and post-test experimental design was used with visual analogue scales to measure sensation and distress of pain. Before surgery, subjects were randomly assigned to receive tape recorded music or the usual care. Those who were assigned to the music group chose among 5 types of sedative music. On postoperative Day 1 and Day 2, the effectiveness of the tape-recorded music was investigated during 15 minutes of rest in bed. Patients were interviewed on Day 3 to determine their liking for the music, its calming effects, and the helpfulness of the music. Repeated measures analysis of variance showed a significant interaction between time and group in the distress of pain on Day 1, but not on Day 2, and in pain sensation on Day 2, but not Day 1. Subjects from Taiwan were similar to subjects in a previous study in the United States in their liking for the music, and in reports of the helpfulness of the music for pain sensation and distress, but fewer Taiwanese found the music calming, and they had different choices: more chose harp music and fewer chose jazz than subjects in the U.S. study, and some would prefer Buddhist hymns or popular songs heard in Taiwan. Findings support the use of culturally acceptable music in addition to analgesic medication for the sensation and distress of postoperative pain.

Differential effects of ibotenic acid lesions of the hippocampus and blockade of N-methyl-D-aspartate receptor-dependent long-term potentiation on contextual processing in rats

The contextual specificity of appetitive conditioned responding was examined in rats undergoing chronic intracerebroventricular infusion of 15 or 30 mM D-2-amino-5-phosphonopentanoic acid (D-AP5) or with excitotoxic hippocampal lesions. The magnitude of conditioned responding by control rats and rats infused with D-AP5 to a conditioned stimulus (CS) trained in Context A was attenuated when the same stimulus was presented in Context B. By contrast, hippocampal-lesioned rats displayed comparable levels of responding to the CS when presented in either Context A or B. Subsequent in vivo electrophysiological investigations showed that the D-AP5 concentrations were effective in blocking long-term potentiation (LTP) in the dentate gyrus. Results indicate that rats are capable of processing contextual information in the absence of N-methyl-D-aspartate (NMDA) receptor-dependent LTP and demonstrate an important dissociation between the effects of hippocampal lesions and the blockade of NMDA receptors in the hippocampus.

Diagnostic value of cerebrospinal fluid examination in children with peripheral facial palsy and suspected Lyme borreliosis

Our objective was to determine the diagnostic value of CSF examinations in the diagnosis of neuroborreliosis in children with peripheral facial palsy (PFP). Paired serum and CSF samples from 21 children with PFP were investigated for antibody responses to Borrelia burgdorferi antigens using three different ELISA systems and one Western blot assay. Twenty of the children (95%) had detectable immunoglobin (Ig) M or IgG in the acute-phase serum, but discrepancies between serologic assays were noted in 33% for IgM and 22 to 50% for IgG. Intrathecal specific-antibody production was detected in five of the 20 seropositive children (25%). These five patients showed seroconversion in convalescent sera in at least one assay. Similar seroconversion suggesting recent infection with B. burgdorferi was observed in eight of the 10 children (80%) without intrathecal specific-antibody production, from whom convalescent serum samples could be obtained. All patients with intrathecal antibodies or seroconversion had shown lymphocytic pleocytosis in the acute phase of PFP. In the acute phase of PFP the detection of intrathecal production of antibodies to B. burgdorferi allows prompt diagnosis of neuroborreliosis. For patients with lymphocytic pleocytosis but no detectable intrathecal antibodies, analysis of convalescent serum may help to establish this diagnosis.

Dissociable effects of selective lesions to hippocampal subsystems on exploratory behavior, contextual learning, and spatial learning

Rats received excitotoxic lesions of different subsystems within the hippocampal system--either the hippocampus proper (cornu ammonis and dentate gyrus; hippocampal lesions) or the entorhinal cortex-subicular region (entorhinal lesions). Subsequently, their activity in an operant chamber was monitored both before and after footshock had been delivered (Experiment 1). Rats with hippocampal lesions showed enhanced activity before the delivery of footshock and reduced freezing after the delivery of shock. Rats with entorhinal lesions showed control levels of activity before the delivery of footshock and control levels of freezing after the delivery of footshock. Both types of lesion impaired spatial learning in a water maze (Experiment 2). These results suggest that the deficits arising from damage to the hippocampal system in contextual and spatial learning have different origins.

Interaction between piloting and beacon homing by rats in a swimming pool

In three experiments, rats in a swimming pool were trained to find a submerged platform with a beacon attached to it. For some rats this beacon unambiguously identified the location of the platform; for others the beacon was made ambiguous by placement of an identical beacon in a different part of the pool. Test trials, in the absence of the platform and the beacons, revealed more persistent searching near the original location of the platform if the beacon attached to the platform had been ambiguous. These results show that learning about the location of the platform, with regard to cues that lie beyond the pool, is influenced by the extent to which an animal can find the platform by relying on other cues. The final experiment shows that this interaction between cues is influenced by an animal's prior experience.

Subject retention in a controlled clinical trial

Threats to subject retention in a controlled clinical trial require strategies that encourage continued participation of subjects, with consideration of the effect of the strategies on the dependent variable. Methods to encourage retention must be based on sensitivity to the patient's changing condition and perspective. Primary considerations in the design and implementation of an intervention study are the acceptability of the intervention to particular patients and the compatibility of the intervention with other care activities. In addition, qualities of the research personnel and changes in patient conditions are important factors in retention of subjects. Vignettes illustrate the threats to retention and solutions used in a clinical trial. Threats to retention include the research nurse's approach and patient factors such as worries, control issues, visitors, symptoms of confusion and pain, and lack of cooperation. Retention strategies include supporting and educating research nurses, providing empathy and respect, including patients in decisions, negotiating with visitors, alleviating symptoms, and supporting a plan of care consistent with both the research protocol and the patient's recovery. While providing a similar approach to all groups, experimental researchers in a variable clinical environment must also provide some individualization and communication to retain valuable subjects who are ill.

Interaction between piloting and beacon homing by rats in a swimming pool

In three experiments, rats in a swimming pool were trained to find a submerged platform with a beacon attached to it. For some rats this beacon unambiguously identified the location of the platform; for others the beacon was made ambiguous by placement of an identical beacon in a different part of the pool. Test trials, in the absence of the platform and the beacons, revealed more persistent searching near the original location of the platform if the beacon attached to the platform had been ambiguous. These results show that learning about the location of the platform, with regard to cues that lie beyond the pool, is influenced by the extent to which an animal can find the platform by relying on other cues. The final experiment shows that this interaction between cues is influenced by an animal's prior experience.

Dissociable effects of selective lesions to hippocampal subsystems on exploratory behavior, contextual learning, and spatial learning

Rats received excitotoxic lesions of different subsystems within the hippocampal system--either the hippocampus proper (cornu ammonis and dentate gyrus; hippocampal lesions) or the entorhinal cortex-subicular region (entorhinal lesions). Subsequently, their activity in an operant chamber was monitored both before and after footshock had been delivered (Experiment 1). Rats with hippocampal lesions showed enhanced activity before the delivery of footshock and reduced freezing after the delivery of shock. Rats with entorhinal lesions showed control levels of activity before the delivery of footshock and control levels of freezing after the delivery of footshock. Both types of lesion impaired spatial learning in a water maze (Experiment 2). These results suggest that the deficits arising from damage to the hippocampal system in contextual and spatial learning have different origins.

[Epidemiological study of sleep disorders in patients in Swiss general practice]

The aim of the study was to assess the prevalence, severity, associated factors and diagnosis of sleep disorders in general practice. Over 700 patients were investigated with a multiple choice questionnaire in 24 general practices in Switzerland. To assess sleep disorders, criterion A for insomnia according DSM-III-R was applied. The prevalence of sleep disorders was 44%, 64% of these were classified as mild, 31% as moderate and 5% as severe. 50% of the female patients complained about insomnia compared to 36% in males. Retrospectively, 74% of the patients stated having suffered from sleep disorders for more than one year (mild 76%, moderate 69%, severe 75%). 70% of patients with mild, 42% with moderate and 30% of patients with severe insomnia didn't inform their physicians about their sleep difficulties on the occasion of an earlier consultations. Patients with moderate or severe insomnia felt moderately or markedly disabled in their quality of life (71%) and work (58%). To estimate general anxiety and depressive state, self-rating scales were used (STAI, D-S). In comparison to reference values for healthy volunteers, insomniac patients had significantly higher scores on both scales, which were associated with the severity of sleep disorders, corroborating the association of sleep disorders with anxiety disorders and depressions. The physicians diagnosed in 18% of insomniacs a psychiatric disease, in 52% a psychoreactive disorder and in 26% a somatic etiology. The study shows that sleep disorders are a frequent syndrome in general practice and often not reported to the physician; therefore, the patients should routinely be questioned about sleep problems, and associated psychiatric diseases should be considered.

Effects of relaxation and music on postoperative pain: a review

Postoperative patients differ in their response to pain and opioids. It is therefore important that nurses offer other options as adjuvants to medication. Relaxation and music may reduce pain by interrupting the postoperative cycle of pain, muscle tension and sympathetic activity. This review summarizes and critiques studies on the effectiveness of relaxation and music use during postoperative pain. Relaxation and music were effective in reducing affective and observed pain in the majority of studies, but they were less often effective in reducing sensory pain or opioid intake. However, the between-study differences in surgical procedures, experimental techniques, activities during testing, measurement of pain, and amount of practice make comparisons difficult. Furthermore, within studies, the problems of inadequate sample size, lack of random assignment, no assurance of pretest equivalence, delayed post-test administration and no control for opiates at the time of testing reduces the validity of the studies' conclusions. Randomized controlled studies of the types of relaxation and music that are most helpful to postoperative patients should be explored in various contexts.

A comparison of the effects of jaw relaxation and music on postoperative pain

This experimental study compared the effects of jaw relaxation and music, individually and combined, on sensory and affective pain following surgery. Abdominal surgical patients (N = 84) were randomly assigned to four groups: relaxation, music, a combination of relaxation and music, and control. Interventions were taught preoperatively and used by subjects during the first ambulation after surgery. Indicators of the sensory component of pain were sensation and 24-hour narcotic intake. Indicators of the affective component of pain were distress and anxiety of pain. With preambulatory sensation, distress, narcotic intake, and preoperative anxiety as covariates, the four groups were compared using orthogonal a priori contrasts and analysis of covariance. The interventions were neither effective nor significantly different from one another during ambulation. However, after keeping the taped interventions for 2 postoperative days, 89% of experimental subjects reported them helpful for sensation and distress of pain.

The avian hippocampus and short-term memory for spatial and non-spatial information

Three experiments investigated the role of the pigeon hippocampal formation (the hippocampus and area-parahippocampalis) in short-term memory for non-spatial and spatial information. The acquisition of delayed matching-to-sample and the short-term retention of non-spatial visual information, using a small set of sample stimuli, were unaffected by aspiration lesions of the hippocampus or the neostriatum (Experiment 1). Similarly, acquisition and short-term retention of non-spatial information using a successive, trial-unique, delayed non-matching-to-sample procedure were unaffected by hippocampal damage; the same birds had, however, displayed a profound autoshaping impairment (Experiment 2). Acquisition of a spatial delayed matching-to-sample task was unimpaired by hippocampal damage. However, lesioned animals were impaired following the introduction of retention intervals on this procedure (Experiment 3). The correspondence between the behavioural effects of hippocampal lesions in birds and mammals on short-term memory is discussed, and the implications of these results for avian hippocampal function are considered.

Hippocampal lesions in pigeons (Columba livia) disrupt reinforced preexposure but not overshadowing or blocking

Three experiments examined the effects of hippocampal lesions in pigeons on overshadowing, blocking, and a latent inhibition treatment (non-differential reinforced preexposure) using a simultaneous visual discrimination paradigm. The results showed that hippocampal damage did not influence overshadowing (Experiment 1) or blocking (Experiment 2) but did attenuate the retardation in conditioning associated with non-differential reinforced preexposure to to-be-discriminated stimuli (Experiment 3). Hippocampal birds also displayed impaired autoshaping (Experiments 1, 2, and 3). The correspondence between the behavioural effects of avian and mammalian hippocampal lesions is discussed, and the implications of the present pattern of results for avian hippocampal function are considered.