Comparison of motor recovery after neonatal and adult hemidecortication

Hemidecortication produces a wide range of cognitive and motor symptoms in both children and lab animals that are generally far greater than smaller bilateral focal lesions of cerebral cortex. Although there have been many studies of motor functions after hemidecortication, the analyses largely have been of general motor functions rather than of more skilled motor functions such as forelimb reaching. The objective of the present experiment was to analyze the sensorimotor forelimb function of rats after infant or adult hemidecortication by utilizing multiple motor analyses. Rats were given hemidecortications either on postnatal day 10 (P10) or day 90 (P90). Both groups were then tested on a number of behavioural tasks (two tests of skilled reaching, forelimb placing during spontaneous vertical exploration, and a sunflower seed opening task) beginning at P 120. In a portion of the P10 female animals, topographic movement representations were derived in the hemisphere contralateral to lesion using Intracortical Microstimulation (ICMS). The brains of the male animals were prepared for Golgi-Cox staining and subsequent analysis of dendritic arborisation and spine density. There were three main findings. 1) Both groups of hemidecorticate animals were impaired when tested on the motor tasks, but the impairments were qualitatively different in the neonatal and adult operates. For example, the P 10 hemidecorticate animals displayed simultaneous bilateral forelimb movement, or "mirror movements." 2) Hemidecortication at P90 but not P10, led to increased dendritic arborisation of Layer III pyramidal cells in the intact parietal cortex but whereas P90 animals showed a decrease in cortical thickness in the intact hemisphere, the P10 animals do not, even though there are no callosal connections. 3) P10 hemidecortication altered the details of the ICMS-delineated motor maps in a small group of female hemidecorticates that were studied. In conclusion, there was postinjury compensation for motor impairments in both P10 and P90 rats but the mechanisms were different. Furthermore, comparisons of postinjury behavioral and anatomical compensation in rats with focal cortical injuries at those ages in our previous studies showed marked differences. These results suggest that there is a fundamental difference in the way that the brain compensates from hemidecortication and focal injury in development.

Stroke: working toward a prioritized world agenda

BACKGROUND AND PURPOSE

The aim of the Synergium was to devise and prioritize new ways of accelerating progress in reducing the risks, effects, and consequences of stroke.

METHODS

Preliminary work was performed by seven working groups of stroke leaders followed by a synergium (a forum for working synergistically together) with approximately 100 additional participants. The resulting draft document had further input from contributors outside the synergium.

RESULTS

Recommendations of the Synergium are: Basic Science, Drug Development and Technology: There is a need to develop: (1) New systems of working together to break down the prevalent 'silo' mentality; (2) New models of vertically integrated basic, clinical, and epidemiological disciplines; and (3) Efficient methods of identifying other relevant areas of science. Stroke Prevention: (1) Establish a global chronic disease prevention initiative with stroke as a major focus. (2) Recognize not only abrupt clinical stroke, but subtle subclinical stroke, the commonest type of cerebrovascular disease, leading to impairments of executive function. (3) Develop, implement and evaluate a population approach for stroke prevention. (4) Develop public health communication strategies using traditional and novel (eg, social media/marketing) techniques. Acute Stroke Management: Continue the establishment of stroke centers, stroke units, regional systems of emergency stroke care and telestroke networks. Brain Recovery and Rehabilitation: (1) Translate best neuroscience, including animal and human studies, into poststroke recovery research and clinical care. (2) Standardize poststroke rehabilitation based on best evidence. (3) Develop consensus on, then implementation of, standardized clinical and surrogate assessments. (4) Carry out rigorous clinical research to advance stroke recovery. Into the 21st Century: Web, Technology and Communications: (1) Work toward global unrestricted access to stroke-related information. (2) Build centralized electronic archives and registries. Foster Cooperation Among Stakeholders (large stroke organizations, nongovernmental organizations, governments, patient organizations and industry) to enhance stroke care. Educate and energize professionals, patients, the public and policy makers by using a 'Brain Health' concept that enables promotion of preventive measures.

CONCLUSIONS

To accelerate progress in stroke, we must reach beyond the current status scientifically, conceptually, and pragmatically. Advances can be made not only by doing, but ceasing to do. Significant savings in time, money, and effort could result from discontinuing practices driven by unsubstantiated opinion, unproven approaches, and financial gain. Systematic integration of knowledge into programs coupled with careful evaluation can speed the pace of progress.

Stroke: working toward a prioritized world agenda

BACKGROUND AND PURPOSE

The aim of the Synergium was to devise and prioritize new ways of accelerating progress in reducing the risks, effects, and consequences of stroke.

METHODS

Preliminary work was performed by 7 working groups of stroke leaders followed by a synergium (a forum for working synergistically together) with approximately 100 additional participants. The resulting draft document had further input from contributors outside the synergium.

RESULTS

Recommendations of the Synergium are: Basic Science, Drug Development and Technology: There is a need to develop: (1) New systems of working together to break down the prevalent "silo" mentality; (2) New models of vertically integrated basic, clinical, and epidemiological disciplines; and (3) Efficient methods of identifying other relevant areas of science. Stroke Prevention: (1) Establish a global chronic disease prevention initiative with stroke as a major focus. (2) Recognize not only abrupt clinical stroke, but subtle subclinical stroke, the commonest type of cerebrovascular disease, leading to impairments of executive function. (3) Develop, implement and evaluate a population approach for stroke prevention. (4) Develop public health communication strategies using traditional and novel (eg, social media/marketing) techniques. Acute Stroke Management: Continue the establishment of stroke centers, stroke units, regional systems of emergency stroke care and telestroke networks. Brain Recovery and Rehabilitation: (1) Translate best neuroscience, including animal and human studies, into poststroke recovery research and clinical care. (2) Standardize poststroke rehabilitation based on best evidence. (3) Develop consensus on, then implementation of, standardized clinical and surrogate assessments. (4) Carry out rigorous clinical research to advance stroke recovery. Into the 21st Century: Web, Technology and Communications: (1) Work toward global unrestricted access to stroke-related information. (2) Build centralized electronic archives and registries. Foster Cooperation Among Stakeholders (large stroke organizations, nongovernmental organizations, governments, patient organizations and industry) to enhance stroke care. Educate and energize professionals, patients, the public and policy makers by using a "Brain Health" concept that enables promotion of preventive measures.

CONCLUSIONS

To accelerate progress in stroke, we must reach beyond the current status scientifically, conceptually, and pragmatically. Advances can be made not only by doing, but ceasing to do. Significant savings in time, money, and effort could result from discontinuing practices driven by unsubstantiated opinion, unproven approaches, and financial gain. Systematic integration of knowledge into programs coupled with careful evaluation can speed the pace of progress.

Stroke: working toward a prioritized world agenda

BACKGROUND AND PURPOSE

The aim of the Synergium was to devise and prioritize new ways of accelerating progress in reducing the risks, effects, and consequences of stroke.

METHODS

Preliminary work was performed by 7 working groups of stroke leaders followed by a synergium (a forum for working synergistically together) with approximately 100 additional participants. The resulting draft document had further input from contributors outside the synergium.

RESULTS

Recommendations of the Synergium are: Basic Science, Drug Development and Technology: There is a need to develop: (1) New systems of working together to break down the prevalent 'silo' mentality; (2) New models of vertically integrated basic, clinical, and epidemiological disciplines; and (3) Efficient methods of identifying other relevant areas of science. Stroke Prevention: (1) Establish a global chronic disease prevention initiative with stroke as a major focus. (2) Recognize not only abrupt clinical stroke, but subtle subclinical stroke, the commonest type of cerebrovascular disease, leading to impairments of executive function. (3) Develop, implement and evaluate a population approach for stroke prevention. (4) Develop public health communication strategies using traditional and novel (e.g., social media/marketing) techniques. Acute Stroke Management: Continue the establishment of stroke centers, stroke units, regional systems of emergency stroke care and telestroke networks. Brain Recovery and Rehabilitation: (1) Translate best neuroscience, including animal and human studies, into poststroke recovery research and clinical care. (2) Standardize poststroke rehabilitation based on best evidence. (3) Develop consensus on, then implementation of, standardized clinical and surrogate assessments. (4) Carry out rigorous clinical research to advance stroke recovery. Into the 21st Century: Web, Technology and Communications: (1) Work toward global unrestricted access to stroke-related information. (2) Build centralized electronic archives and registries. Foster Cooperation Among Stakeholders (large stroke organizations, nongovernmental organizations, governments, patient organizations and industry) to enhance stroke care. Educate and energize professionals, patients, the public and policy makers by using a 'Brain Health' concept that enables promotion of preventive measures.

CONCLUSIONS

To accelerate progress in stroke, we must reach beyond the current status scientifically, conceptually, and pragmatically. Advances can be made not only by doing, but ceasing to do. Significant savings in time, money, and effort could result from discontinuing practices driven by unsubstantiated opinion, unproven approaches, and financial gain. Systematic integration of knowledge into programs coupled with careful evaluation can speed the pace of progress.

Recordings of extracellular glutamate and gamma-aminobutyric acid in the striatum of non-anesthetized rats. K(+)-stimulation, its Ca(2+)-dependence and lack of effects of drugs acting on dopamine receptors

The extracellular concentrations of glutamate (GLU) or gamma-aminobutyric acid (GABA) in the striatum were determined in non-anesthetized, non-restrained rats using the microdialysis method, and the effects of some dopaminergic drugs were studied. Since a great part of these amino acids in the extracellular space is probably of origin not related to neurotransmission, the percentage of amino acids of neuronal origin was increased by stimulation with K+ added to the perfusion medium, and the Ca(2+)-dependence of K+ stimulated release was checked. This stimulation was performed twice in most of the experiments, under standard condition and after specific manipulations. K+ (100 mmol/l) produced pronounced increases in the overflow of GLU and even more of GABA. Omission of Ca2+ and addition of 20 mmol/l of Mg2+ in the medium significantly decreased the K(+)-stimulated overflow of GLU, but not of GABA. However, when in the whole perfusion procedure K+ was elevated and, initially, the medium was kept Ca(2+)-free, but contained 20 mmol/l of Mg2+, and subsequently was replaced by a medium containing Ca2+, but no Mg2+, then the shift to the second medium led to considerable increases in overflow both of GLU and GABA indicating a partial Ca(2+)-dependence of K(+)-stimulated overflow and suggesting at least a partial neuronal origin of the extracellular amino acids. In subsequent experiments, dopaminergic drugs were administered systemically before the second stimulation with K+. Apomorphine (2 mg/kg s.c.) had no effect on the K(+)-stimulated GABA overflow.(ABSTRACT TRUNCATED AT 250 WORDS)

The postweaning housing environment determines expression of learning deficit associated with neonatal monosodium glutamate (M.S.G.)

Perinatal M.S.G. treatment causes a syndrome characterized by damage to the hypothalamic arcuate nucleus, other circumventricular areas, parts of the visual system and the dentate gyrus of the hippocampus. The resulting hormonal dysfunction may be responsible for developmental anomalies of organ systems, obesity, and alterations in sensory/motor performance. We have shown that some behavioral indicators of M.S.G. toxicity in rats can be masked by rearing them in enriched housing conditions. Here, we evaluated the impact of six housing conditions on M.S.G.-induced alterations of organ systems and behavior. Perinatal M.S.G. treatment reduced adrenal, heart and testes weights, as well as total white blood cell (WBC) counts, and increased tail flick latencies. These measures were unaffected by the housing condition. M.S.G.-induced reductions in body weight, grip strength, water maze and dominance task performance varied as a function of housing. Deficits in water maze performance were most evident following social and isolated single-cage housing. We propose that deficits in water maze performance following perinatal M.S.G. may be attributable to hippocampal damage that can be alleviated by rearing the rats in stimulating environments.

[Psychological tests of epileptic patients]

A total of 140 epileptic patients were examined using psychological tests in a combined psychiatric and psychological study to assess cognitive malfunctions. Compared with a control group, significantly lower levels of performance were shown in intelligence, concentration and psychomotoric speed, but not in memory. Surprisingly, there was no uniform relationship between the degree of performance deficit and the severity of fits, perhaps with the exception of intelligence. Missing significant memory malfunctions restrict the value of a so-called organic psychosyndrome, the relevance of which is doubtful from the neurospychological point of view, anyway.