By M. Grobock. West Virginia Wesleyan College.
Older neuroanatomical and neurophysio- logical data suggested that this was the case; e order alendronate 35mg line. However buy alendronate 70mg amex, newer neuroanatomical data demonstrate that this is an ever present theme in the structure and function of neural systems order alendronate 35 mg with amex. For instance buy discount alendronate 35mg on line, outputs from the basal ganglia, once thought to be a motor learning structure, project to layer I of all primary sensory cortical areas,27 likely inﬂuencing the processing of all cortical cells with dendrites extending into layer I. Data such as these indicate that sensory and motor areas are continuously interacting via multiple, parallel looping structures. Likewise, all sen- sory thalamic relay nuclei including the ventroposterior lateral thalamus (VPI) (pro- cessing somatosensory information), the medial geniculate thalamus (MGN) (pro- cessing auditory information) and the lateral geniculate thalamus (LGN) (processing visual data) receive axon collaterals of layer V efferents from primary motor cortex (M1) and the premotor cortex. Thus, descending motor commands appear able to modulate or even drive thalamic sensory processing. The constant interaction of sensory and motor data streams is manifest in mam- malian behavior in myriad instances. For example, the strength of an odor modulates snifﬁng intensity, even on the ﬁrst sniff of the odor. For instance, while recording single units from the digit-wrist area of caudal M1 and the magnocellular red nucleus as rats perform this task, we have found that many neurons in both areas that code the overt arm-movement phases are strongly modulated by olfactory information taken in during the ﬁnal sniff of the food target just prior to lifting the paw12 (Figure 7. In fact, the caudal M1 in rats is distinguished by having layer IV somatosensory inputs,5 whereas most motor regions in mammals lack layer IV sensory inputs. Correspondingly, we have found that many rat M1 units are partic- ularly active during phases of the reaching task in which somatosensory information is being evaluated, such as lifting the paw off the ground, brushing the paw against M1 cell, FINAL SNIFF mRN cell, FINAL SNIFF sig001c sig019a 80 20 60 15 40 10 20 5 0 0 -1 -0. The percentages below each graph show the proportion of single units recorded in each area that displayed such signiﬁcant modulation on the ﬁnal sniff. M1 cell, LIFT M1 cell, ONSHELF M1 cell, CONTACT sig011a sig012c sig005a 40 60 30 40 30 40 20 20 10 20 10 0 0 0 -1 -0. However, in one study we conducted, the inadequacy of that model was strikingly illustrated. As animals became more proﬁcient at the task, roughly one third of all recorded S1 units developed much longer latencies consistent with motor processing, and roughly one third of all recorded M1 cells developed early, somatosensory latencies. PRINCIPLE II: INFORMATION FROM MULTIPLE SPATIAL SCALES IS PROCESSED SIMULTANEOUSLY Three or four decades ago, many researchers advocated the view that mammalian sensory systems represent their sensory surfaces topographically and with high resolution, and that the high resolution, body centered information gained at the sensory surface was gradually transformed at higher levels of the nervous system by cells with progressively larger receptive ﬁelds into object-centered representa- tions. However, it is now widely recognized that information is processed at multiple spatial scales simultaneously. For instance, at the somatosensory surface, Type I cutaneous recep- tors process mechanical somatosensory data with high spatial resolution, while Type II receptors have larger, less well deﬁned receptive ﬁelds. For instance, it has recently been discovered that in many thalamic nuclei, a matrix of calbindin-immunoreactive cells projects diffusely throughout the cortex, irrespective of sensory topography or even sensory domain. For example, the relay nucleus for body somatosensory afferents, VPL, contains both parvalbumin-positive, precisely projecting, somatotopically organized afferents to layer IV of cortical area SI, with correspondingly small receptive ﬁelds, as well as much more widely pro- jecting, calbindin-staining cells whose axons target the superﬁcial cortical layers in multiple sensory modalities. It is now hypothesized that these diffusely projecting cells play a critical role in coordinating activity across brain regions, particularly in view of evidence that many layer IV corticothalamic feedback neurons target these transcortically projecting matrix cells. For example, much like the thalamic relay nuclei, the striatum of the basal ganglia contains topographically more ordered regions that process information with high spatial resolution (striosomes), as well more diffusely orga- nized regions26 (matrix cells). And the relative lack of topographical ordering in the cerebellum, where instead distant regions of the body surface are adjacently located in the cerebellar cortex,19 is thought to promote sensorimotor learning across the whole body. Behavioral tasks therefore either need to be extremely well controlled if they are to be based primarily on the hypothesis of high resolution, topographic processing (e. PRINCIPLE III: LABORATORY ANIMALS ARE CONSTANTLY EVALUATING INFORMATION ACROSS MULTIPLE TIME SCALES IN ORDER TO MORE ACCURATELY PREDICT WHAT WILL HAPPEN IN THEIR WORLD It is now widely agreed that mammals – like nearly all species with nervous systems – are constantly re-evaluating the past at different time scales and com- bining the resulting knowledge with their current perceptions in order to predict the future at different time scales. The sample appears to gain skill in a linear fashion over the course of the ﬁrst six training days, when it then begins to asymptote at its highest performance level. Many older task models were based on the simplifying assumption that tasks were learned and maintained as a simple function of the number of training trials up through reaching an asymptotic performance level, and degraded as a simple function of lack of practice or interference by new memories.
Over the course of the 50-min-period burst conditioning caused an increase in the functional connectivity between the barrel columns receiving paired input cheap alendronate 35 mg online. In contrast generic alendronate 35mg otc, inter-burst conditioning caused no sig- niﬁcant modiﬁcation in the functional connectivity between the cortical barrel col- umns receiving paired input cheap 70mg alendronate with mastercard. Since the total number of stimuli delivered to the two pairs of whiskers as well as the temporal patterning of the stimuli was equal discount alendronate 35mg mastercard, the different degree of modiﬁcation must be attributed to rapid modulations in the modiﬁability of cortex. The ﬁgure illustrates the results from an experiment that was typical of the complete set of experiments,19 the same case shown in Figure 3. Part A shows the cross-correlation index between neurons in barrel columns E2 and E3 (black points) and between neurons in barrel columns C2 and C3 (gray points). During the preconditioning period (0–10 min), the strength of cross correlation between the E2-E3 and C2-C3 barrel columns was equal. At t = 10 min, the conditioning period began, during which neurons in barrel columns E2 and E3 underwent burst conditioning, while neurons in barrel-columns C2 and C3 underwent inter-burst conditioning (see Figure 3. For both stimulated pairs, the amount of correlated activity increased immediately as would be expected due to the paired whisker stimulation. At t = 30 min, the correlation index for the E2-E3 pair rose dramatically while the correlation index for the C2-C3 pair remained at a constant level. By the conclusion of the 50 min conditioning paradigm (t = 60 min), the stimulus induced correlation was approximately twice as great for the burst conditioned neurons (barrel columns E2-E3) as for the inter-burst conditioned neurons (barrel columns C2-C3). The cross-correlation index for the inter-burst-conditioned neurons immediately returned to the preconditioning level. But the cross correlation index for the burst conditioned neurons remained elevated. The modiﬁcation in effective connectivity for the burst conditioned neurons was still present at t = 85 min, 25 min after the conclusion of the conditioning protocol. Changes in intracortical connectivity for this experiment are summarized in Figure 3. Cross correlation histograms were constructed separately from ﬁve 10- min intervals labeled a–e in Figure 3. Before conditioning (interval a) and shortly after the onset of conditioning (interval b), the cross correlation histograms for the burst-conditioned neurons, the inter-burst conditioned neurons were equivalent. By the ﬁnal 10 min of the conditioning period (interval c), the cross-correlation histo- grams for the burst-conditioned neurons had grown larger, while that for the inter- burst-conditioned neurons was practically unchanged. Cross-correlation index between burst-conditioned and inter-burst-conditioned cortical columns. Sensory responses before and after conditioning in the burst-conditioned and inter-burst-conditioned cortical columns. TIMING-BASED PLASTICITY OF SENSORY RESPONSES Sensory responses also were modiﬁed by the conditioning protocol. Paired whisker stimuli were applied before conditioning and then at 70–75 min and 85–90 min. These results show that the cortex in anesthetized animals can be modiﬁed by sensory input patterns only during discrete intermittent intervals. Stimuli delivered during bursts – short intervals of elevated spontaneous activity – were effective in modifying cortical connectivity, whereas stimuli delivered in the intervals between bursts, though matching in number and temporal pattern, were ineffective. In all experiments, the conditioning paradigm produced a comparable degree of plasticity in the burst-triggered channels. POSSIBLE MECHANISMS FOR RAPID FLUCTUATIONS IN PLASTICITY Our preferred explanation is that neuromodulatory substances, in particular Acetyl- choline (ACh), are released in sensory cortex during the peak of the cortical © 2005 by Taylor & Francis Group. If the bursting of basal forebrain neurons causes a transient elevation in cortical ACh concentration, this could complement the increased synaptic reliability present during cortical bursts. Another candidate as a modulatory input, whose activity is linked to barrel cortex bursts, is the intralaminar thalamic nuclei. LOCUS OF MODIFICATION In awake, attentive animals, training on sensory discrimination tasks or periods of altered sensory experience cause changes in somatosensory cortical-receptive ﬁelds and cortical maps. Modiﬁcation of effective intracortical connectivity has been proposed as one of the candidate mechanisms to account for the plasticity of the sensory cortex.
This is one of the fundamental reasons why KM does not have a widely accepted framework that can enable healthcare institutions in creating KM systems and a culture conducive to KM practices trusted 35mg alendronate. KM is underpinned by information technology paradigms such as Workflow cheap alendronate 35mg on-line, Intelligent Agents and Data Mining cheap alendronate 35 mg otc. According to Manchester (1999) buy discount alendronate 70mg line, a common point about software technologies such as (1) information retrieval, (2) document management and (3) workflow processing is that they blend well with the Internet and related technologies (i. As KM deals with the tacit and contextual aspects of information, it allows an organi- zation to know what is important for it in particular circumstances, in the process maximizing the value of that information and creating competitive advantages and wealth. Applicability of the KM Paradigm in Healthcare A KM solution would allow healthcare institutions to give clinical data context, so as to allow knowledge derivation for more effective clinical diagnoses. In the future, healthcare systems would see increased interest in knowledge recycling of the collaborative Copyright © 2005, Idea Group Inc. Copying or distributing in print or electronic forms without written permission of Idea Group Inc. Issues in Clinical Knowledge Management 7 learning process acquired from previous healthcare industry practices. This chapter puts forward the notion that this sector has been exclusively focused on IT to meet the challenges described above and reiterates that this challenge cannot be met by an IT led solution. KM initiatives should be incorporated within the technological revolution that is speeding across healthcare industry. There has to be balance between organizational and technological aspects of the healthcare process, that is, one cannot exist without the other (Dwivedi et al. This chapter emphasizes the importance of clinicians taking a holistic view of their organization. Clinicians therefore need to have an understanding of IT in a healthcare context and a shared vision of the organization. Clinicians and healthcare administrators thus need to acquire both organizational and technological insights if they are to have a holistic view of their organization. The KM paradigm can enable the healthcare sector to successfully overcome the information and knowledge explosion, made possible by adopting a KM framework that is specially customized for healthcare institutions in light of their ICT implementation level. Adoption of KM is essential for healthcare institutions as it would enable them to identify, preserve and disseminate “best context” healthcare practices to different healthcare stakeholders. Prefatory Analysis of Alternative Healthcare Concepts The failure of some healthcare management concepts propelled a new stream of thought that advocated the incorporation of the KM paradigm in healthcare (Health Canada, 1999; Mercer, 2001). KM could allow healthcare organizations to truly take advantage of the driving forces behind the creation of the CHIN concept. However, very few organizations have adopted a comprehensive healthcare KM system. The main reason attributed is the failure of healthcare stakeholders in properly creating a conducive organizational Table 1. Prefatory analysis of alternative healthcare concepts Concept Support for People Support for Process Support for Technology Limitations CG Present Insufficient Present Policy initiative EBM Insufficient Insufficient Present Tacit Processes? CHIN Insufficient Absent Present Limited Trials IHCDS Insufficient Insufficient Present Technology focus IPP Insufficient Present Present Tacit Knowledge? Copying or distributing in print or electronic forms without written permission of Idea Group Inc. Based on a literature review above, a preliminary conceptual analysis of alternative healthcare management concepts is presented in Table 1. Healthcare institutions have realized that existing concepts such as EBM and CG do not enable healthcare stakeholders to achieve this challenge as they do not holistically support effective integration of IT within specific organizational cultures and processes. Contem- porary concepts such as EBM, CHIN, ICHDS and IPP focus on IT at the expense of having too little emphasis on people. This is further aggravated by the presence of dysfunctional organizational processes in the majority of healthcare institutions. Conclusion For any healthcare organization to succeed, it needs to excel in a number of key processes (i. Modern IT applications in healthcare are not sufficient in meeting the information needs of current healthcare institutions as they lack the ability to deliver precise, accurate and contextual information to the desired caregiver at the desired time. This chapter has presented an analysis of alternative healthcare management concepts with respect to their ability in providing a solution to the issue of information manage- ment.
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