Microglial reactions to retrograde degeneration of tracer-identified thalamic neurons after frontal sensorimotor cortex lesions in adult rats

1996 ◽  
Vol 112 (2) ◽  
Author(s):  
J.C. S�rensen ◽  
I. Dalmau ◽  
J. Zimmer ◽  
B. Finsen
Keyword(s):  
Sensorimotor Cortex ◽  
Adult Rats ◽  
Thalamic Neurons ◽  
Retrograde Degeneration

scholarly journals Pattern of chondroitin sulfate proteoglycan expression after ablation of the sensorimotor cortex of the neonatal and adult rat brain

2008 ◽  
Vol 60 (4) ◽  
pp. 581-591
Author(s):  
Sanja Dacic ◽  
Sanja Pekovic ◽  
Maja Stojiljkovic ◽  
Irena Lavrnja ◽  
Danijela Stojkov ◽  
...  
Keyword(s):  
Chondroitin Sulfate ◽  
Rat Brain ◽  
Sensorimotor Cortex ◽  
Immunohistochemical Analysis ◽  
Recovery Process ◽  
Adult Brain ◽  
Sulfate Proteoglycan ◽  
Adult Rats ◽  
Adult Rat ◽  
Adult Rat Brain

The central nervous system has a limited capacity for self-repair after damage. However, the neonatal brain has agreater capacity for recovery than the adult brain. These differences in the regenerative capability depend on local environmental factors and the maturational stage of growing axons. Among molecules which have both growth-promoting and growth-inhibiting activities is the heterogeneous class of chondroitin sulfate proteoglycans (CSPGs). In this paper, we investigated the chondroitin-4 and chondroitin-6 sulfate proteoglycan expression profile after left sensorimotor cortex ablation of the neonatal and adult rat brain. Immunohistochemical analysis revealed that compared to the normal uninjured cortex, lesion provoked up regulation of CSPGs showing a different pattern of expression in the neonatal vs. the adult brain. Punctuate and membrane-bound labeling was predominate after neonatal lesion, where as heavy deposition of staining in the extracellular matrix was observed after adult lesion. Heavy deposition of CSPG immunoreactivity around the lesionsite in adult rats, in contrast to a less CSPG-rich environment in neonatal rats, indicated that enhancement of the recovery process after neonatal injury is due to amore permissive environment.

scholarly journals Development of Thalamocortical Response Transformations in the Rat Whisker-Barrel System

2008 ◽  
Vol 99 (1) ◽  
pp. 356-366 ◽  
Author(s):  
Michael Shoykhet ◽  
Daniel J. Simons
Keyword(s):  
Cortical Neurons ◽  
Time Course ◽  
Receptive Fields ◽  
Second Phase ◽  
Adult Rats ◽  
Response Latencies ◽  
Thalamic Neurons ◽  
Response Properties ◽  
Temporal Domain

Extracellular single-unit recordings were used to characterize responses of thalamic barreloid and cortical barrel neurons to controlled whisker deflections in 2, 3-, and 4-wk-old and adult rats in vivo under fentanyl analgesia. Results indicate that response properties of thalamic and cortical neurons diverge during development. Responses to deflection onsets and offsets among thalamic neurons mature in parallel, whereas among cortical neurons responses to deflection offsets become disproportionately smaller with age. Thalamic neuron receptive fields become more multiwhisker, whereas those of cortical neurons become more single-whisker. Thalamic neurons develop a higher degree of angular selectivity, whereas that of cortical neurons remains constant. In the temporal domain, response latencies decrease both in thalamic and cortical neurons, but the maturation time-course differs between the two populations. Response latencies of thalamic cells decrease primarily between 2 and 3 wk of life, whereas response latencies of cortical neurons decrease in two distinct steps—the first between 2 and 3 wk of life and the second between the fourth postnatal week and adulthood. Although the first step likely reflects similar subcortical changes, the second phase likely corresponds to developmental myelination of thalamocortical fibers. Divergent development of thalamic and cortical response properties indicates that thalamocortical circuits in the whisker-to-barrel pathway undergo protracted maturation after 2 wk of life and provides a potential substrate for experience-dependent plasticity during this time.

scholarly journals Basic Fibroblast Growth Factor Prevents Thalamic Degeneration after Cortical Infarction

1991 ◽  
Vol 11 (3) ◽  
pp. 472-478 ◽  
Author(s):  
Kazuo Yamada ◽  
Akira Kinoshita ◽  
Eiji Kohmura ◽  
Tateo Sakaguchi ◽  
Junji Taguchi ◽  
...  
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Basic Fibroblast Growth Factor ◽  
Normal Saline ◽  
Contralateral Side ◽  
Fibroblast Growth ◽  
Rat Serum ◽  
Thalamic Neurons ◽  
Retrograde Degeneration ◽  
Ventral Thalamus

In the focal infarction model of the rat middle cerebral artery (MCA), the thalamus of the occluded side becomes gradually atrophic, mainly because of retrograde degeneration. We determined whether basic fibroblast growth factor (bFGF) administered intracisternally could prevent this thalamic atrophy. We occluded the left MCA through a small cranial opening, and animals were then divided into two groups. One group received intra-cisternal injections of recombinant bFGF (1 μg dissolved in 0.1 ml of saline with 2% rat serum) starting 1 day after occlusion and repeated once a week to a total dose of 4 μg by four injections. The other group received vehicle solution by the same schedule. The animals were perfused and fixed at 28 days after occlusion, and histological examination was made at the level of the caudoputamen and thalamus. In the bFGF-treated rats, the area of the posterior ventral thalamus of the occluded side was 93% of that of the contralateral side, i.e., significantly larger than in the normal saline-treated rats (75%, p < 0.01). The infarction size was not statistically different in the two groups. Microscopic observation indicated that normal-saline-treated animals showed shrinkage and disappearance of thalamic neurons, whereas bFGF-treated groups showed preservation of thalamic neurons. Computerized analysis of the cell size substantiated this observation. To assess the effect of bFGF on astrocytes, bFGF or vehicle solution was injected into normal rats, and their histology was evaluated at 1, 2, and 4 weeks after injection. The bFGF-injected group showed a significant increase in glial fibrillary acidic protein-positive astrocytes in the brain tissue facing the ventriculocisternal system. The results suggest that bFGF prevents retrograde degeneration of thalamic neurons by working directly as a neurotrophic factor of these neurons or by activating astrocytes located in the thalamocortical pathway.

scholarly journals Delayed Treatment with Monoclonal Antibody IN-1 1 Week after Stroke Results in Recovery of Function and Corticorubral Plasticity in Adult Rats

2005 ◽  
Vol 25 (10) ◽  
pp. 1366-1375 ◽  
Author(s):  
Andrew B Seymour ◽  
Ellen M Andrews ◽  
Shih-Yen Tsai ◽  
Tiffanie M Markus ◽  
Melanie R Bollnow ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Functional Recovery ◽  
Sensorimotor Cortex ◽  
Recovery Of Function ◽  
Focal Cerebral Ischemia ◽  
Red Nucleus ◽  
Neurite Growth ◽  
Inhibitory Protein ◽  
Adult Rats ◽  
Reaching Task

Neuronal death due to ischemic stroke results in permanent deficits in sensory, language, and motor functions. The growth-restrictive environment of the adult central nervous system (CNS) is an obstacle to functional recovery after stroke and other CNS injuries. In this regard, Nogo-A is a potent neurite growth-inhibitory protein known to restrict neuronal plasticity in adults. Previously, we have found that treatment with monoclonal antibody (mAb) IN-1 to neutralize Nogo-A immediately after stroke enhanced motor cortico-efferent plasticity and recovery of skilled forelimb function in rats. However, immediate treatment for stroke is often not clinically feasible. Thus, the present study was undertaken to determine whether cortico-efferent plasticity and functional recovery would occur if treatment with mAb IN-1 was delayed 1 week after stroke. Adult rats were trained on a forelimb-reaching task, and the middle cerebral artery was occluded to induce focal cerebral ischemia to the forelimb sensorimotor cortex. After 1 week, animals received mAb IN-1 treatment, control antibody, or no treatment, and were tested for 9 more weeks. To assess cortico-efferent plasticity, the sensorimotor cortex opposite the stroke lesion was injected with an anterograde neuroanatomical tracer. Behavioral analysis demonstrated a recovery of skilled forelimb function, and anatomical studies revealed neuroplasticity at the level of the red nucleus in animals treated with mAb IN-1, thus demonstrating the efficacy of this treatment even if administered 1 week after stroke.

scholarly journals Enhanced Behavioral Recovery from Sensorimotor Cortex Lesions After Pyramidotomy in Adult Rats

2000 ◽  
Vol 7 (4) ◽  
pp. 261-277 ◽  
Author(s):  
V. V. Fanardjian ◽  
O. V. Gevorkyan ◽  
R. K. Mallina ◽  
A. B. Melik-Moussian ◽  
I. B. Meliksetyan
Keyword(s):  
Sensorimotor Cortex ◽  
Inferior Olive ◽  
Behavioral Recovery ◽  
Peripheral Part ◽  
Adult Rats ◽  
Recovery Processes ◽  
Spinal Projection ◽  
Descending Influences ◽  
Rubrospinal System ◽  
System Switching

Unilateral transection of the bulbar pyramid, performed before the ablation of the ipsilateral sensorimotor cortex, has been shown to facilitate the recovery of operantly conditioned reflexes and compensatory processes in rats. Such enhanced behaviorai recovery was absent when only the sensorimotor cortex was ablated. This phenomenon is explained by the switching of motor activity under the control of the cortico-rubrospinal system. Switching of the descending influences is accomplished through the following loop: cortico-rubrai projectionred nucleus-inferior olive-cerebellum-thalamuscerebral cortex. This suggests that a preliminary lesion of the peripheral part of the system, represented by a descending spinal projection, facilitates the recovery processes to develop during the subsequent destruction of its central part.

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