Products of the PLP gene, proteolipid protein and its isoform DM-20, are the most abundant proteins in CNS myelin, and are markers of the oligodendrocyte, the myelin-forming cell in the CNS. The DM-20 transcript has previously been reported to be expressed in newborn oligodendrocyte progenitor cells and during embryonic development. We have therefore used a DM-20 cRNA probe to follow, by in situ hybridization, the oligodendrocyte lineage during embryonic development. DM-20-expressing cells were first detected at E9.5 in the ventricular germinal layer of the laterobasal plate of the diencephalon. At E14.5, DM-20+ cells had largely disappeared from the diencephalic ventricular germinal layer and had colonized the ventral mantle layer at the posterior part of the basal diencephalon. Between E17.5 and P1, the number of DM-20+ cells increased and progressively invaded the major white matter tracts. In the hindbrain, DM-20+ cells appeared at E12.5 in the caudal part of the rhombencephalon, and at E14.5 all along the ventral spinal cord. Between E14.5 and P1, DM-20+ cells progressively colonized, first ventrally then dorsally, all the spinal cord and more extensively the white matter tracts. At E14.5, a large gap separated, rostrally, the medullary columns from the mantle layer cells in the prosencephalon, suggesting that oligodendrocytes in the mid- and forebrain originate from a different pool of precursors than in the rhombencephalon and the spinal cord. Together, these observations suggest that expression of the DM-20 transcript is an early marker of commitment to the oligodendrocyte lineage, and that oligodendrocyte precursors originate in a ventrally restricted region.

We investigated in vivo the expression of the tissue inhibitor of metalloproteinases-1 (TIMP-1) in the rat CNS after kainate (KA)-induced excitotoxic seizures. In situ hybridization revealed that TIMP-1 mRNA is induced rapidly and massively in most regions of the adult forebrain after KA treatment. Neuronal activity seems to be necessary but not sufficient to trigger TIMP-1 induction, because it is not observed in seizing 10-d-old pups, unlike what is observed in 21-and 35-d-old animals after seizures. The rapid induction of TIMP-1 is not prevented by the inhibitor of protein synthesis cycloheximide, suggesting that, after seizures, TIMP-1 is induced in neurons as an immediate early gene (IEG). The initial neuronal upregulation is followed by enhanced expression in astrocytes, as assessed by double-labeling experiments. In the hippocampus rapid increases in mRNA are followed by relatively delayed (8 hr after KA) increases in TIMP-1 immunoreactivity in the perisomatic and dendro-axonic areas, suggesting secretion of the protein. At 3 d after KA treatment, strong immunoreactivity is found in astrocytes and in the cell bodies and dendro-axonic projections of resistant neurons such as the dentate granule cells. Taken together, the results suggest that TIMP-1 may be instrumental for neurons and astrocytes in coupling early cellular events triggered by seizures with the regulation of long-lasting changes involved in tissue reorganization and/or neuroprotection.

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In the early stage after stroke, within the first 2 weeks, physical therapy (PT) has 2 main goals: prevent immobilityrelated events and stimulate motor control recovery. However, the amount of PT to provide and the time after stroke for provision remain unclear.The organization of care in multidisciplinary stroke units has reduced the risk of death and dependency after stroke, with early mobilization and rehabilitation having an important role.1-3 Very early mobilization (VEM) was defined by the AVERT group (A Very Early Rehabilitation Trial): within the first 24 hours, focusing on out-of-bed activity (sitting, standing, walking), provided at least 3× more than usual care, by physical therapists or nurses. VEM has been found safe and feasible, 4 with a significant positive effect on recovery of walking 50 m unassisted, good functional prognosis on Barthel index at 3 months, 5 and for the frequency of severe complications. 6 Hemorrhagic stroke patients showed a better level of function (walking >15.24 m). 7 The recent European recommendations 8 and those from the American Stroke Association 9 promote VEM, although how early and how much a patient should be mobilized remains controversial. Some negative impact of early (<24 hours) versus delayed (<48 hours) physical rehabilitation has been reported, with increased risk of death. 10Background and Purpose-Intensive physical therapy (PT) facilitates motor recovery when provided during a subacute stage after stroke. The efficiency of very early intensive PT has been less investigated. We aimed to investigate whether intensive PT conducted within the first 2 weeks could aid recovery of motor control. Methods-This multicentre randomized controlled trial compared soft PT (20-min/d apart from respiratory needs) and intensive PT (idem+45 minutes of intensive exercises/day) initiated within the first 72 hours after a first hemispheric stroke. The primary outcome was change in motor control between day (D) 90 and D0 assessed by the Fugl-Meyer score. Main secondary outcomes were number of days to walking 10 m unassisted, balance, autonomy, quality of life, and unexpected medical events. All analyses were by intent to treat. Results-We could analyze data for 103 of the 104 included patients (51 control and 52 experimental group; 64 males; median age overall 67 [interquartile range 59-77], 67 right hemispheric lesions, 80 ischemic lesions, National Institutes of Health Stroke Scale score ≥8 for 82%). Fugl-Meyer score increased over time (P<0.0001), with no significant effect of treatment (P=0.29) or interaction between treatment and time (P=0.40). The median change in score between D90 and D0 was 27.5 (12-40) and 22.0 (12-56) for control and experimental groups (P=0.69). Similar results were found for the secondary criteria. Conclusions-Very early after stroke, intensive exercises may not be efficient in improving motor control. This conclusion may apply to mainly severe stroke. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01520636.

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URL: http://www.clinicaltrials.gov. Unique identifier: NCT01994720.

Background and Purpose— The TST trial (Treat Stroke to Target) evaluated the benefit of targeting a LDL (low-density lipoprotein) cholesterol of <70 mg/dL to reduce the risk of cardiovascular events in 2860 patients with ischemic stroke with atherosclerotic stenosis of cerebral vasculature or aortic arch plaque >4 mm, in a French and Korean population. The follow-up lasted a median of 5.3 years in French patients (similar to the median follow-up time in the SPARCL trial [Stroke Prevention by Aggressive Reduction in Cholesterol Level]) and 2.0 years in Korean patients. Exposure duration to statin is a well-known driver for cardiovascular risk reduction. We report here the TST results in the French cohort. Methods— One thousand seventy-three French patients were assigned to <70 mg/dL (1.8 mmol/L) and 1075 to 100±10 mg/dL (90–110 mg/dL, 2.3–2.8 mmol/L). To achieve these goals, investigators used the statin and dosage of their choice and added ezetimibe on top if needed. The primary outcome was the composite of ischemic stroke, myocardial infarction, new symptoms requiring urgent coronary or carotid revascularization and vascular death. Results— After a median follow-up of 5.3 years, the achieved LDL cholesterol was 66 (1.69 mmol/L) and 96 mg/dL (2.46 mmol/L) on average, respectively. The primary end point occurred in 9.6% and 12.9% of patients, respectively (HR, 0.74 [95% CI, 0.57–0.94]; P =0.019). Cerebral infarction or urgent carotid revascularization following transient ischemic attack was reduced by 27% ( P =0.046). Cerebral infarction or intracranial hemorrhage was reduced by 28% ( P =0.023). The primary outcome or intracranial hemorrhage was reduced by 25% ( P =0.021). Intracranial hemorrhages occurred in 13 and 11 patients, respectively (HR, 1.17 [95% CI, 0.53–2.62]; P =0.70). Conclusions— After an ischemic stroke of documented atherosclerotic origin, targeting a LDL cholesterol of <70 mg/dL during 5.3 years avoided 1 subsequent major vascular event in 4 (number needed to treat of 30) and no increase in intracranial hemorrhage. Registration— URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01252875.

We analyzed by in situ hybridization the spatiotemporal expression of dm-20, myelin basic protein (MBP) and 2'-3' cyclic nucleotide phosphodiesterase (CNP) during embryonic and postnatal development of the normal mouse and two plp/dm-20 mutants: the jimpy mouse and a transgenic mouse overexpressing the plp gene. In the central nervous system (CNS) of the normal mouse, dm-20 mRNA was detected at embryonic day (E)9.5 in the laterobasal plate of the diencephalon. The pattern of expression of CNP transcript was superimposable on that of dm-20, but appeared slightly later, at E12.5. MBP mRNA was detected even later (E14.5), and, in addition, only in the caudal (rhombencephalon and spinal cord) territories of expression of dm-20 and CNP. These observations support our previous proposals: (1) dm-20-expressing cells in the germinative neuroepithelium are precursors of oligodendrocytes, and (2) oligodendrocytes emerge from distinct pools of precursors along the neural tube (Timsit et al., 1995). In the jimpy mutant, despite the mutation in the plp gene, cells of the oligodendrocyte lineage developed normally. It is only at the time of myelin deposition that oligodendrocytes die. During embryonic development of the transgenic mutant overexpressing plp, there were no alterations in the spatiotemporal pattern or the level of expression of dm-20 in the CNS, in contrast to the higher levels of dm-20 observed in the peripheral nervous system (PNS).