Heading direction with respect to a reference point modulates place-cell activity.

The tuning of neurons in area CA1 of the hippocampus emerges through a combination of non-spatial input from different sensory modalities and spatial information about the animal's position and heading direction relative to the spatial enclosure being navigated. The positional modulation of CA1 neuronal responses has been widely studied (e.g. place tuning), but less is known about the modulation of these neurons by heading direction. Here, utilizing electrophysiological recordings from CA1 pyramidal cells in freely moving mice, we report that a majority of neural responses are modulated by the heading-direction of the animal relative to a point within or outside their enclosure that we call a reference point. The finding of heading-direction modulation relative to reference points identifies a novel representation encoded in the neuronal responses of the dorsal hippocampus.

Using Clinical Signs and Symptoms for Medical Management of Radiation Casualties - 2015 NATO Exercise.

The utility of early-phase (≤5 days) radiation-induced clinical signs and symptoms (e.g., vomiting, diarrhea, erythema and changes in blood cell counts) was examined for the prediction of later occurring acute radiation syndrome (ARS) severity and the development of medical management strategies. Medical treatment protocols for radiation accident victims (METREPOL) was used to grade ARS severities, which were assigned response categories (RCs). Data on individuals (n = 191) with mild (RC1, n = 45), moderate (RC2, n = 19), severe (RC3, n = 20) and fatal (RC4, n = 18) ARS, as well as nonexposed individuals (RC0, n = 89) were generated using either METREPOL (n = 167) or the system for evaluation and archiving of radiation accidents based on case histories (SEARCH) database (n = 24), the latter comprised of real-case descriptions. These data were converted into tables reflecting clinical signs and symptoms, and submitted to eight teams representing five participating countries. The teams were comprised of medical doctors, biologists and pharmacists with subject matter expertise. The tables comprised cumulated clinical data from day 1-3 and day 1-5 postirradiation. While it would have reflected a more realistic scenario to provide the data to the teams over the course of a 3- or 5-day period, the logistics of doing so proved too challenging. In addition, the team members participating in this exercise chose to receive the cumulated reports of day 1-3 and 1-5. The teams were tasked with predicting ARS incidence, ARS severity and the requirement for hospitalization for multiple cases, as well as providing the certainty of their diagnosis. Five of the teams also performed dose estimates. The teams did not employ harmonized methodologies, and the expertise among the members varied, as did the tools used and the means of analyzing the clinical data. The earliest report time was 3 h after the tables were sent to the team members. The majority of cases developing ARS (89.6% ± 3.3 SD) and requiring hospitalization (88.8% ± 4.6 SD) were correctly identified by all teams. Determination of ARS severity was particularly challenging for RC2-3, which was systematically overestimated. However, RC4 was correctly predicted at 94-100% by all teams. RC0 and RC1 ARS severities were more difficult to discriminate. When reported RCs (0-1 and 3-4) were merged, on average 89.6% (±3.3 SD) of all cases could be correctly classified. Comparisons on frequency distributions revealed no statistically significant differences among the following: 1. reported ARS from different teams (P > 0.2); 2. cases generated based on METREPOL or SEARCH (P > 0.5); or 3. results reported at day 3 and 5 postirradiation (P > 0.1). Dose estimates of all teams increased significantly along with ARS severity (P < 0.0001) as well as with dose estimates generated from dicentric chromosomal-aberration measurements available for SEARCH cases (P < 0.0001). In summary, early-phase radiation-induced clinical signs and symptoms proved to be useful for rapid and accurate assessment, with minor limitations, toward predicting life-threatening ARS severity and developing treatment management strategies.

Task-related dissociation of EEG ß enhancement and suppression.

Previous investigations of EEG ß processes can be divided into two categories: one in which ß enhancement is obtained and one in which ß suppression is obtained. The current study investigated the ß band range (14-30Hz) by subdividing the signal into 2Hz sub-bands. We presented participants with photographs of faces expressing happy, angry, sad or neutral expressions under two primary tasks in which participants judged the emotion the individual was expressing, or how the way the other person feels makes the participant feel. Results revealed a pattern of both ß suppression and enhancement that appeared to depend on whether the task required first-person emotional experience (self-task) or perspective-taking (other-task). Specifically, the self-task was associated with enhancement while the other-task was associated with suppression. While some previous research has reported ß enhancement to emotion-inducing stimuli, other research has reported ß suppression in tasks also associated with mu suppression. To our knowledge, the current data are the first to reveal both ß enhancement and suppression within a single experiment and suggests a neurocognitive dissociation of enhancement and suppression within the ß band range.

Attentional distraction, µ-suppression and empathic perspective-taking.

Social mirroring has been proposed to be an automatic process whereby an observer understands the intentions of others by using his/her motor system to simulate others' actions. Automaticity implies that if the observer's eyes are fixed on another person, the observer's mirror system will engage whether attention is focused on the other person or not. This proposal has not been fully tested, however. The current study therefore addressed whether µ-suppression, an electroencephalographic measure of putative mirror neuron activity, induced by observing the actions of others would be affected by attentional distraction. Participants performed two different distraction tasks while watching a video of a hand repeatedly touching the forefinger and thumb together. µ-suppression was compared across three different blocks: (1) video with no distraction, (2) video with mental imagery distraction and (3) video with word generation distraction. While the no distraction condition yielded the typical level of µ-suppression, the word generation distraction task eliminated any evidence of µ-suppression suggesting that simply fixating the eyes on an action without focusing attention is insufficient to induce µ-suppression. A secondary goal of the current experiment was to replicate correlational findings between µ-suppression and empathic perspective-taking. A counterintuitive, negative relationship between µ-suppression and perspective-taking was replicated, and a theoretical model for explaining this relationship is offered.

Differences in self- and other-induced Mu suppression are correlated with empathic abilities.

Recent research suggests a role of the human mirror neuron system in empathic processing. Electroencephalographic (EEG) mu suppression in the 8-13Hz band-range has been proposed to reflect mirror-like activation of sensorimotor cortices. We therefore investigated the relationship between suppression in the 8-13Hz range and empathic abilities as measured by the Interpersonal Reactivity Index (IRI). Based on previous work showing significant differences between execution- and observation-related mu suppression and on theories of empathy pointing to the importance of discriminating self from other, we predicted that the size of this difference within individuals would correlate with participants' perspective-taking abilities. Larger differences in execution- and observation-induced mu suppression were associated with greater scores on the perspective-taking subscale of the IRI. The current data are therefore consistent with the claim that neural activity reflected in mu suppression is related to empathic abilities.

Atomised lidocaine for airway topical anaesthesia in the morbidly obese: 1% compared with 2%.

Airway anaesthesia using atomised lidocaine for awake oral fibreoptic intubation in morbidly obese patients was evaluated using two doses of local anaesthetic. In this randomised, blinded prospective study, 40 ml of atomised 1% (n = 11) or 2% (n = 10) lidocaine was administered with high oxygen flow as carrier. Outcomes included time for intubation, patient tolerance to airway manipulation, haemodynamic parameters, the bronchoscopist's overall satisfaction, and serial serum lidocaine concentrations. Patients receiving lidocaine 1% had a longer mean (SD) time from the start of topicalisation to tracheal tube cuff inflation than those receiving lidocaine 2% (8.6 (0.9) min vs 6.9 (0.5) min, respectively; p < 0.05). Patients in the 1% cohort demonstrated increased responses to airway manipulation (p < 0.0001), reflecting lower bronchoscopist's satisfaction scores (p < 0.03). Haemodynamic responses to topicalisation and airway manipulation were similar in both groups. Peak plasma concentration was lower in the 1% group (mean (SD) 1.4 (0.3) and 3.8 (0.5) microg.ml(-1), respectively; p < 0.001). Airway anaesthesia using atomised lidocaine for awake oral fibreoptic intubation in the morbidly obese is efficacious, rapid and safe. Compared with lidocaine 1%, the 2% dose provides superior intubating conditions.

Brain regions and their dynamics in prospective memory retrieval: a MEG study.

We measured brain activity using magnetoencephalography in five participants during ongoing tasks that included prospective memory, retrospective memory, and oddball trials. Sources were identified in the hippocampal formation and posterior parietal and frontal lobes. Posterior parietal cortex activation had an earlier onset in the prospective memory condition than retrospective memory or oddball conditions, a higher level of theta activity in the retrospective condition, and higher levels of upper alpha in the prospective and oddball conditions. Activation of the hippocampal formation had a longer duration in the retrospective memory and prospective memory conditions than the oddball condition, but prominent alpha and theta band activity was present in all three conditions. We interpret the early (87 ms) onset of activity in parietal cortex as evidence for an initial noticing of appropriate conditions for a PM response. Hippocampal activity may reflect a subsequent memory search for the intended action.

Neural correlates of differential retrieval orientation: Sustained and item-related components.

Retrieval orientation refers to a cognitive state that biases processing of retrieval cues in service of a specific goal. The present study used a mixed fMRI design to investigate whether adoption of different retrieval orientations - as indexed by differences in the activity elicited by retrieval cues corresponding to unstudied items - is associated with differences in the state-related activity sustained across a block of test trials sharing a common retrieval goal. Subjects studied mixed lists comprising visually presented words and pictures. They then undertook a series of short test blocks in which all test items were visually presented words. The blocks varied according to whether the test items were used to cue retrieval of studied words or studied pictures. In several regions, neural activity elicited by correctly classified new items differed according to whether words or pictures were the targeted material. The loci of these effects suggest that one factor driving differential cue processing is modulation of the degree of overlap between cue and targeted memory representations. In addition to these item-related effects, neural activity sustained throughout the test blocks also differed according to the nature of the targeted material. These findings indicate that the adoption of different retrieval orientations is associated with distinct neural states. The loci of these sustained effects were distinct from those where new item activity varied, suggesting that the effects may play a role in biasing retrieval cue processing in favor of the current retrieval goal.

Electrophysiological dissociation of the neural correlates of recollection and familiarity.

Event-related potentials (ERPs) were employed to investigate electrophysiological correlates of recognition memory in a task that allowed segregation of test items according to whether they were recollected (operationalized by introspective report) or, if recollection failed, their level of familiarity (operationalized by recognition confidence). The amplitude of a negative-going ERP deflection that onsets around 300 ms post-stimulus varied inversely with familiarity strength. This effect was maximal over the left frontal scalp. It did not differ between the ERPs elicited by highly familiar versus recollected items, indicating that the recollection is not merely a consequence of strong familiarity. By contrast, a later positive deflection (onset ca. 500 ms post-stimulus) was enhanced in ERPs elicited by recollected relative to highly familiar items. This effect was maximal over the left posterior scalp and was insensitive to familiarity, as indicated by its absence in the contrast between items judged highly familiar versus highly unfamiliar. The findings constitute a double dissociation between the neural correlates of recollection and familiarity. Together with the results of a parallel functional magnetic resonance imaging study (A.P. Yonelinas et al., J. Neurosci. (2005), 25, 3002-3008), they indicate that recollection and familiarity rely on qualitatively distinct neural systems and strongly support dual-process models of recognition memory.

MEG reveals different contributions of somatomotor cortex and cerebellum to simple reaction time after temporally structured cues.

Magnetoencephalography (MEG) was used to measure brain activity while participants performed a simple reaction to targets after either a random interval (uncued targets) or a series of isochronous warning stimuli with 200-ms intervals that acted as a countdown. Targets could arrive "on time" or "early" relative to the preceding warning stimuli. Cerebellar activity before any stimulus onset predicted uncued simple reaction time. Onset of activity in somatomotor cortex relative to the target predicted reaction time after two warning stimuli when the target arrived on time or early. After three warning stimuli, when the target arrived on time and was certain to occur, prestimulus cerebellar activity and somatomotor onset were significant predictors of reaction time. When the target arrived early after three warning stimuli, prestimulus cerebellar and cingulate activity were predictive. The cerebellar results may reflect a number of possible factors, including a role in timing, response readiness, prediction and attention.

Age-related effects on superior temporal gyrus activity during an auditory oddball task.

We used magnetoencephalography in combination with magnetic resonance imaging to investigate the effects of aging on the temporal dynamics of activity localized to several brain regions during an auditory oddball task. The most interesting effects were noted in the superior temporal gyrus as follows: (1) responses were generally stronger to rare than to frequent tones throughout the entire 600-ms time interval, and (2) increases in the amplitude of the 40-ms peak and the latency of the maximum late response were evident in the elderly. Although superior temporal gyrus activity has traditionally been associated with early sensory processing, these results suggest that superior temporal gyrus activity is also important for later decision-related processing.

Content-specificity of the neural correlates of recollection.

It is widely assumed that episodic retrieval (recollection) involves reinstatement of cortical activity engaged during the processing of an episode when it was initially experienced. It follows from this assumption that the cortical correlates of recollection should differ with the content of what is recollected, and that retrieval of different content should be associated with activity in functionally distinct cortical regions. The present experiment investigated these predictions. Subjects (N=17) studied a mixed list of words and pictures and were then presented with a test list comprised of words only. Test items were studied words, the names of studied pictures, and unstudied (new) words. Functional magnetic resonance images were acquired while the subjects made Remember/Know/New judgments to these test words. Independent of study material, studied items endorsed as Remembered elicited greater activity than correctly classified unstudied items in several regions, including left frontal, left lateral parietal, and posterior cingulate cortex. In addition, Remembered items elicited greater activity in the right hippocampus and parahippocampal gyrus than items accorded Know judgments, replicating previous findings. Analysis of content-specific effects demonstrated a regional double-dissociation within left fusiform cortex; recollected words elicited greater activity than recollected pictures in lateral fusiform, whereas the reverse effect was evident in an anterior fusiform region. The lateral and anterior fusiform areas correspond closely to areas held to be functionally specialized for the processing of visual words and pictures, respectively. Thus, the current findings support the cortical reinstatement hypothesis of episodic retrieval.

The evolution of optometric education in America.

BACKGROUND: The first American optometry law was passed in Minnesota 100 years ago. That law--and the others that followed--determined the minimal educational requirements to practice optometry. Legislating the practice of optometry was the first step in changing optometric education, from a short course in refraction to an accredited university program. As the practice of optometry has changed and evolved over the past 100 years, so has the optometry school education. PURPOSE: This article chronicles the changes that have occurred in optometric education during this evolutionary period.

Effect of telephone followups on post vasectomy office visits.

Vasectomies are considered minor outpatient procedures. Yet, many patients return to their urologist's office for rechecks because of complications or the need for reassurance of normal healing sequela. This study suggests that use of a tool for telephone followup can increase patient satisfaction and benefit urologic practice by curtailing the incidence of needless followup visits.

Biosynthesis of triacylglycerols containing ricinoleate in castor microsomes using 1-acyl-2-oleoyl-sn-glycero-3-phosphocholine as the substrate of oleoyl-12-hydroxylase.

We have examined the biosynthetic pathway of triacylglycerols containing ricinoleate to determine the steps in the pathway that lead to the high levels of ricinoleate incorporation in castor oil. The biosynthetic pathway was studied by analysis of products resulting from castor microsomal incubation of 1-palmitoyl-2-[14C]oleoyl-sn-glycero-3-phosphocholine, the substrate of oleoyl-12-hydroxylase, using high-performance liquid chromatography, gas chromatography, mass spectrometry, and/or thin-layer chromatography. In addition to formation of the immediate and major metabolite, 1-palmitoyl-2-[14C]ricinoleoyl-sn-glycero-3-phosphocholine, 14C-labeled 2-linoleoyl-phosphatidylcholine (PC), and 14C-labeled phosphatidylethanolamine were also identified as the metabolites. In addition, the four triacylglycerols that constitute castor oil, triricinolein, 1,2-diricinoleoyl-3-oleoyl-sn-glycerol, 1,2-diricinoleoyl-3-linoleoyl-sn-glycerol, 1,2-diricinoleoyl-3-linolenoyl-sn-glycerol, were also identified as labeled metabolites in the incubation along with labeled fatty acids: ricinoleate, oleate, and linoleate. The conversion of PC to free fatty acids by phospholipase A2 strongly favored ricinoleate among the fatty acids on the sn-2 position of PC. A major metabolite, 1-palmitoyl-2-oleoyl-sn-glycerol, was identified as the phospholipase C hydrolyte of the substrate; however, its conversion to triacylglycerols was blocked. In the separate incubations of 2-[14C]ricinoleoyl-PC and [14C]ricinoleate plus CoA, the metabolites were free ricinoleate and the same triacylglycerols that result from incubation with 2-oleoyl-PC. Our results demonstrate the proposed pathway: 2-oleoyl-PC-->2-ricinoleoyl-PC-->ricinoleate-->triacylglycerols. The first two steps as well as the step of diacylglycerol acyltransferase show preference for producing ricinoleate and incorporating it in triacylglycerols over oleate and linoleate. Thus, the productions of these triacylglycerols in this relatively short incubation (30 min), as well as the availability of 2-oleoyl-PC in vivo, reflect the in vivo drive to produce triricinolein in castor bean.

Volunteer facilitators assist community practices with enhancing cancer control.

OBJECTIVE: To explore the feasibility of recruiting, training, and placing in the field volunteers to assist community practices in enhancing the provision of preventive care. DESIGN: A case series design followed up a cohort of volunteers prospectively as they were recruited, trained, and assigned to practices. SETTING: The New Hampshire Division of the American Cancer Society recruited and trained the volunteer facilitators. INTERVENTION: Assistance from the volunteers in implementing a preventive services office system served as the intervention for practices. Volunteers were trained and supported by professional staff and an implementation manual. MAIN OUTCOME MEASURES: Recruitment, training, and volunteer experiences in working with practices, as well as the costs of supporting the program, were assessed. RESULTS: Twenty-six volunteers were trained. Of the 15 assigned to practices, 11 had begun to assist their assigned practices to establish a preventive services office system. Extensive planning, patience, and support were required. CONCLUSION: Volunteers recruited and supported by an intermediary organization can provide assistance to practices in implementing a preventive services office system.

Durability of improved physician early detection of cancer after conclusion of intervention support.

Physicians can potentially play an important role in the early detection of cancer. Interventions designed to encourage these activities have been shown to improve physician performance for up to 1 year. To assess their real value, improved physician performance must be judged over the longer term. The Cancer Prevention in Community Practice Project assisted a random subset of practices in implementing cancer early detection office systems. One year later, these practices were found to have provided more indicated breast and colorectal cancer early detection services than practices that did not receive assistance. This report addresses whether 12-month improvements in breast and colorectal cancer early detection were durable at 24 months despite no appreciable ongoing project support. A cross-sectional survey of 20-30 established patients/practice was conducted 24 months after the introduction of the intervention. These results were compared with base-line, 6-, and 12-month cross-sectional surveys to determine whether increases in indicated services and recommendations persisted. A longitudinal model for binomial data was used to quantitatively assess durability of effects. Ninety-nine practices participated, and 81 provided data at all 4 evaluation intervals. In office systems practices, improvements in stool occult blood testing and self breast examination recommendations to patients were maintained between 12 and 24 months while improvements in mammography recommendations and clinical breast examinations declined somewhat but remained superior to performance in control practices. Some improvements in physician early detection of cancer performance were maintained between 12 and 24 months. Future studies of physician behavior change should include follow-up beyond 12 months.

Changing office routines to enhance preventive care. The preventive GAPS approach.

While family physicians aspire to provide their patients with the best possible preventive care, the services actually provided sometimes fall short of this ideal. Enhancing the provision of preventive care may require changes in office operations. Through working with more than 200 community practices in the Cancer Prevention in Community Practice Project, we have developed the Preventive GAPS Approach, which can help physicians and their practice staff to enhance their preventive care. The approach is based on teamwork among clinicians, staff, and patients; routines that encourage opportunistic provision of indicated preventive care; and flexibility, which allows physicians and their staffs to tailor their improvement strategy and the pace of change to their own unique situation. The approach includes the following four-step method (or GAPS): goal setting regarding preventive care; assessment of existing routines that support preventive care and of the current level of attainment of preventive goals; planning to modify existing routines that support preventive care; and starting and maintaining the improved preventive care office system.