Plasticity of astrocytes derived from aged mouse cerebral hemispheres: Changes with cell passage and immortalization

Grove, Jerome; Gómez, Jorge; Kentroti, Susan; Vernadakis, Antonia

doi:10.1016/0361-9230(95)02130-2

Cited by 15 publications

(6 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This observation is in agreement with previous studies, showing trkA protein and mRNA expression by reactive astrocytes (but not microglia or oligodendrocytes) in different human gliosis-associated pathologies and experimentally induced models in rats [39,41,42,46,47,50,66]. Because astrocytes can respond to neurotrophins in a receptor-mediated pathway [67,68] and are capable of producing the trkA ligand NGF [69,70], it is likely that this neurotrophin may function as an autocrine or paracrine factor in trkA-expressing reactive astroglial cells. Because it has been reported that in the presence of NGF reactive astrocytes can act as conductive substrates for axon growth [71], trkA expression in reactive astrocytes has been theorized to serve a role in structural plasticity [72].…”

Section: Distribution Of Ntrs In Hssupporting

confidence: 92%

Neurotrophin receptor immunoreactivity in the hippocampus of patients with mesial temporal lobe epilepsy

Özbas‐Gerçeker

Gorter

Redeker

et al. 2004

Neuropathology Appl Neurobio

View full text Add to dashboard Cite

Recent evidence supports a critical role of neurotrophins in the regulation of both neuronal survival and synaptic transmission during epileptogenesis. We have examined the immunohistochemical expression of high- (tyrosine kinase receptors, trk) and low-affinity (p75) neurotrophin receptors (NTRs) in the hippocampal specimens from 18 patients with chronic temporal lobe epilepsy [TLE; 14 patients with hippocampal sclerosis (HS) and four with focal lesions (tumours) not involving the hippocampus proper]. Nonepileptic autopsy brains (n = 6) and surgical specimens from tumour patients without epilepsy (n = 3) were used as controls. Immunoreactivity (IR) for the trk receptors (trkA, trkB, trkC) was detected in normal human brain within the pyramidal neurones of hippocampal cornus ammoni (CA) regions and in the dentate gyrus. There were no detectable differences in the neuronal trk IR patterns in the hippocampus between control and TLE cases with HS, except for a decrease in neuronal density in regions where cell death had occurred (CA1, CA3 and CA4). In contrast, a consistent increase in trkA IR was observed in reactive astrocytes in CA1 and dentate gyrus. The low-affinity p75 neurotrophin receptor (p75(NTR)) was expressed in low levels in postnatal normal hippocampus. In contrast, neuronal p75(NTR) IR was detected in 10/14 cases of HS in spared neurones within the CA and hilar regions of the hippocampus. Double labelling revealed that p75(NTR)-positive neurones also contain trk receptor IR. In six cases with prominent glial activation strong p75(NTR) IR was observed in microglial cells within the sclerotic hippocampus. The present results indicate that changes in NTR expression are still detectable in the hippocampus of patients with chronic TLE and involve both glial and neuronal cells. Reactive astrocytes were immunoreactive for trkA, whereas activated microglia cells were reactive for p75(NTR), suggesting different functions for specific NTRs in the development of reactive gliosis. Moreover, the increased expression of p75(NTR) in hippocampal neurones of TLE patients may critically influence the neuronal survival during the epileptogenic process.

show abstract

Section: Distribution Of Ntrs In Hssupporting

confidence: 92%

Neurotrophin receptor immunoreactivity in the hippocampus of patients with mesial temporal lobe epilepsy

Özbas‐Gerçeker

Gorter

Redeker

et al. 2004

Neuropathology Appl Neurobio

View full text Add to dashboard Cite

show abstract

“…Our finding that granule cell endosomes contained the p75 NTR indicates that the receptor, which may or may not be bound with ligand, is endocytosed by these cells; because the endosomes we observed were located in the perinuclear region, they may be late endosomes that contain labeled p75 NTR destined for lysosomal degradation (Kornfeld and Mellman, 1989). The p75 NTR and trk receptors have previously been detected in oligodendrocytes and astrocytes derived from cortical tissue maintained in vitro by using immunocytochemical and immunoprecipitation techniques (Rudge et al, 1992;CasacciaBonnefil et al, 1996;Grove et al, 1998). Moreover, a large number of existing reports have indicated that a variety of glial cell types exhibit receptor-mediated responses to the neurotrophins under both normal and pathological conditions (Bernard et al, 1988;Kumar et al, 1993;Yokoyama et al, 1993;Junier et al, 1994;Rudge et al, 1995).…”

Section: Functional Significancementioning

confidence: 77%

p75NTR immunoreactivity in the rat dentate gyrus is mostly within presynaptic profiles but is also found in some astrocytic and postsynaptic profiles

Dougherty

Milner

1999

J. Comp. Neurol.

View full text Add to dashboard Cite

To localize neurotrophin binding sites within the rat dentate gyrus, the distribution of low‐affinity p75 neurotrophin receptor (p75NTR) immunoreactivity (IR) was examined by using antiserum raised against the cytoplasmic domain of the receptor. Semiquantitative electron microscopic examination of p75NTR‐labeled sections showed that most p75NTR‐labeled profiles were axons and axon terminals (72% from a total of 3,975); p75NTR‐IR was observed throughout the extent of these structures and was not limited to the plasmalemmal surface. Axons and axon terminals containing p75NTR‐IR were distributed in approximately equal proportions across the hilus, infragranular zone, and the inner, middle, and outer molecular layers; significantly fewer p75NTR‐labeled profiles were observed in the granule cell layer. Axon terminals containing p75NTR‐IR, which made synapses (296 of 552), formed equal proportions of symmetric and asymmetric synapses, primarily with the shafts and spines of dendrites. The remainder of the p75NTR‐labeled terminals apposed unlabeled somata and dendrites without forming synapses in the single sections analyzed. In addition, p75NTR‐IR was contained within some astrocytes (17.5% of 3,975) and dendritic shafts (3%) and spines (5%). Within dendritic spines, p75NTR‐IR was most often associated with the plasmalemmal surface near postsynaptic densities; in dendritic shafts, p75NTR labeling was associated with microfilaments distant from the plasmalemma. Most p75NTR‐labeled dendritic profiles were located in the molecular layer, and some originated from granule cells. Moreover, in some granule cell somata (<1% of 3,975), p75NTR‐IR was associated with endosomes. The primary localization of p75NTR‐IR to presynaptic structures in the dentate gyrus, presumably arising from medial septal/diagonal band neurons, agrees with previous reports. However, p75NTR‐IR within some astrocytes, somata, and dendritic structures suggests that this receptor may also be involved in controlling local neurotrophin levels and possibly modulating the viability of local hippocampal cell populations. J. Comp. Neurol. 407:77–91, 1999. © 1999 Wiley‐Liss, Inc.

show abstract

“…Activated astrocytes appear within hours in the nervous system in response to diverse physical and chemical conditions (Althaus and Richter-Landsberg, 2000), increase TrkA expression (Wang et al, 1998), and can respond to neurotrophins in a receptor-mediated pathway (Grove et al, 1996). Interestingly, activated astrocytes also have been shown to express the TrkA ligand, NGF (Eddleston and Mucke, 1993;Althaus and Richter-Landsberg, 2000).…”

Section: Trka Immunoreactive Astrocytesmentioning

confidence: 97%

TrkA immunoreactive astrocytes in dendritic fields of the hippocampal formation across estrous

McCarthy

Barker-Gibb²,

Alves³

et al. 2002

Glia

View full text Add to dashboard Cite

Neurotrophins are important modulators of structural synaptic plasticity. (Through trophic action (Jordan. J Neurobiol 40:434-445, 1999), astrocytes serve as permissive substrates to support axonal regrowth (Ridet et al. Trends Neurosci 20:570-571, 1997), and are involved in estrogen-induced synaptic structural plasticity (Garcia-Segura et al. Cell Mol Neurobiol 16:225-237, 1996). Previously, we reported that tyrosine kinase A receptor (TrkA) immunoreactivity was present both in presynaptic neuronal processes (axons and terminals) and in select astrocytes of the male rat hippocampal formation (Barker-Gibb et al. J Comp Neurol 430:182-199, 2001). We show that the number of TrkA-immunoreactive astrocytes in female rats fluctuates 16-fold across the estrous cycle in dendritic fields of the hippocampal formation, with the greatest number at estrus after the peak plasma estradiol concentration of proestrus. Few TrkA-labeled astrocytes were found in ovariectomized animals; after estrogen replacement, this number increased by 12-fold in the hippocampal formation, indicating estrogen-mediated induction. Dual-labeling studies showed that TrkA-labeled astrocytes were also immunoreactive for vimentin, a protein expressed by reactive astrocytes. Ultrastructural analysis of the dentate gyrus molecular layer demonstrated that TrkA immunoreactive astrocytes are positioned primarily next to dendrites and unmyelinated axons. Because nerve growth factor (NGF) has been reported to stimulate astrocytes to function as substrates for axon growth (Kawaja and Gage. Neuron 7:1019-1030, 1991), these findings are consistent with the theory that TrkA immunoreactive astrocytes serve a role in structural plasticity, axon guidance, and synaptic regeneration across the estrous cycle in the hippocampal formation.

show abstract

Plasticity of astrocytes derived from aged mouse cerebral hemispheres: Changes with cell passage and immortalization

Cited by 15 publications

References 30 publications

Neurotrophin receptor immunoreactivity in the hippocampus of patients with mesial temporal lobe epilepsy

Neurotrophin receptor immunoreactivity in the hippocampus of patients with mesial temporal lobe epilepsy

p75NTR immunoreactivity in the rat dentate gyrus is mostly within presynaptic profiles but is also found in some astrocytic and postsynaptic profiles

TrkA immunoreactive astrocytes in dendritic fields of the hippocampal formation across estrous

Contact Info

Product

Resources

About