Increased Expression of Microtubule-Associated Protein 1B in the Hippocampus, Subiculum, and Perforant Path of Rats Treated with a High Dose of Pentylenetetrazole

Popa‐Wagner, Aurel; Fischer, Barbara; Schmoll, Harald; Platt, D.; Kessler, C.

doi:10.1006/exnr.1997.6652

Cited by 17 publications

(10 citation statements)

References 45 publications

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“…Of note, nestin expression also was increased in the CA2 region of the hippocampus, suggesting input from the subiculum [14]. An early increase in proliferating radial glia-like astrocytes in the dentate gyrus after kainate-induced seizures that is consistent with a recruitment of precursors for seizure-induced neurogenesis also has been previously reported [15], [16].…”

Section: Discussionsupporting

confidence: 78%

Repeated PTZ Treatment at 25-Day Intervals Leads to a Highly Efficient Accumulation of Doublecortin in the Dorsal Hippocampus of Rats

et al. 2012

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BackgroundNeurogenesis persists throughout life in the adult mammalian brain. Because neurogenesis can only be assessed in postmortem tissue, its functional significance remains undetermined, and identifying an in vivo correlate of neurogenesis has become an important goal. By studying pentylenetetrazole-induced brain stimulation in a rat model of kindling we accidentally discovered that 25±1 days periodic stimulation of Sprague-Dawley rats led to a highly efficient increase in seizure susceptibility.Methodology/Principal FindingsBy EEG, RT-PCR, western blotting and immunohistochemistry, we show that repeated convulsive seizures with a periodicity of 25±1 days led to an enrichment of newly generated neurons, that were BrdU-positive in the dentate gyrus at day 25±1 post-seizure. At the same time, there was a massive increase in the number of neurons expressing the migratory marker, doublecortin, at the boundary between the granule cell layer and the polymorphic layer in the dorsal hippocampus. Some of these migrating neurons were also positive for NeuN, a marker for adult neurons.Conclusion/SignificanceOur results suggest that the increased susceptibility to seizure at day 25±1 post-treatment is coincident with a critical time required for newborn neurons to differentiate and integrate into the existing hippocampal network, and outlines the importance of the dorsal hippocampus for seizure-related neurogenesis. This model can be used as an in vivo correlate of neurogenesis to study basic questions related to neurogenesis and to the neurogenic mechanisms that contribute to the development of epilepsy.

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Section: Discussionsupporting

confidence: 78%

Repeated PTZ Treatment at 25-Day Intervals Leads to a Highly Efficient Accumulation of Doublecortin in the Dorsal Hippocampus of Rats

et al. 2012

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“…Similar varicosities have recently been detected on axonal extensions in cultured dorsal root ganglion neurons [45], suggesting that MAP1B accumulation in varicosities is an indicator of growth phenomena and can be a measure of cortical plasticity. A similar string-of-beads morphology has been reported by us in the cortex of rats after seizure activity, which is regarded as a model of synaptic plasticity [46]. This inference is further supported by data showing that MAP1B plays a role in neuronal differentiation [47] and axonal formation [48,49] whereby MAP1B acts as a surface receptor for myelin-associated glycoprotein (MAG) [45,50].…”

Section: Discussionsupporting

confidence: 59%

Temporal Dynamics of Degenerative and Regenerative Events Associated with Cerebral Ischemia in Aged Rats

Badan

Platt²,

Kessler

et al. 2003

Gerontology

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Background and Purpose: The age-related decline in plasticity of the brain may be one factor underlying the poor functional recovery after stroke. In the present work we tested the hypothesis that the attenuation of neural plasticity could be the result of an age-related reduction in the upregulation of factors promoting brain plasticity (microtubule-associated protein 1B [MAP1B], β-amyloid precursor protein [βAPP]), and an age-related increase in glial reactivity and the accumulation of Aβ, a proteolytic cleavage product of βAPP with neurotoxic properties. Methods: Focal cerebral ischemia was produced by reversible occlusion of the right middle cerebral artery in 3- and 20-month-old male Sprague-Dawley rats. The functional outcome was assessed in neurobehavioral tests 3, 7, 14 and 28 days after surgery. At the indicated time points, brains were removed and immunostained for glial cells. Aβ, as well as the markers of brain plasticity, βAPP and MAP1B. Results: Histologically, in young rats there was a gradual activation of both microglia and astrocytes that peaked by days 14–28 with the formation of a glial scar. In contrast, aged rats showed an accelerated astrocytic and microglial reaction that peaked in the first week after stroke. The expression patterns of a growth-associated phenotype of βAPP as well as with MAP1B accumulation in varicosities along axons in cortical areas affected by stroke peaked between days 14 and 28 in young animals. In aged rats their expression was both delayed (28 days) and reduced. In addition the carboxy terminal fragment of βAPP steadily accumulated over time and reached a maximum by day 14 in aged rats as compared to 28 days in young rats. Conclusions: These results suggest that a temporally anomalous gliotic reaction to cerebral ischemia in aged rats in conjunction with a late and limited upregulation of neuronal plasticity proteins as well as a diminished neurogenesis potential lead to the prevalence of scar tissue that impedes functional recovery from stroke.

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“…, 2001), suggesting that MAP1B accumulation in varicosities is an indicator of growth phenomena and can be a measure of cortical plasticity. Interestingly, we have observed a similar string‐of‐beads morphology in the cortex of rats after seizure activity, which is regarded as a model of synaptic plasticity (Popa‐Wagner et al. , 1997).…”

Section: Discussionmentioning

confidence: 65%

Accelerated accumulation of N‐ and C‐terminal βAPP fragments and delayed recovery of microtubule‐associated protein 1B expression following stroke in aged rats

Badan

Dinca

Buchhold

et al. 2004

Eur J of Neuroscience

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The age-related decline in plasticity of the brain may be one factor underlying poor functional recovery after stroke. In the present work we tested the hypothesis that the attenuation of neural plasticity in old age could be the result of an altered temporal relationship between factors promoting brain plasticity [microtubule-associated protein 1B (MAP1B)] and neurotoxic factors such as C-terminal betaAPP. Focal cerebral ischemia was produced by reversible occlusion of the right middle cerebral artery in 3- and 20-month-old male Sprague-Dawley rats. The functional outcome was assessed in neurobehavioral tests at 3, 7, 14 and 28 days after surgery. At the indicated timepoints, brains were removed and immunostained for C- and N-terminal betaAPP and MAP1B. At 2 weeks poststroke, we found an age-related increase in the amount of the C-terminal fragment of betaAPP in the peri-infarcted area and the infarct core as well as an early, vigorous incorporation of N-terminal betaAPP into the developing astroglial scar. The recovery of the plasticity-associated protein MAP1B following stroke was delayed in both age groups and became prominent between days 14 and 28. As aged rats showed diminished functional recovery compared with young rats, these results suggest that the accumulation of C-terminal betaAPP, together with the early incorporation of N-terminal betaAPP into the glial scar, may over-ride the beneficial role of plasticity factors such as MAP1B.

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Increased Expression of Microtubule-Associated Protein 1B in the Hippocampus, Subiculum, and Perforant Path of Rats Treated with a High Dose of Pentylenetetrazole

Cited by 17 publications

References 45 publications

Repeated PTZ Treatment at 25-Day Intervals Leads to a Highly Efficient Accumulation of Doublecortin in the Dorsal Hippocampus of Rats

Repeated PTZ Treatment at 25-Day Intervals Leads to a Highly Efficient Accumulation of Doublecortin in the Dorsal Hippocampus of Rats

Temporal Dynamics of Degenerative and Regenerative Events Associated with Cerebral Ischemia in Aged Rats

Accelerated accumulation of N‐ and C‐terminal βAPP fragments and delayed recovery of microtubule‐associated protein 1B expression following stroke in aged rats

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