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Spatial learning and memory following fimbria-fornix transection and grafting of fetal septal neurons to the hippocampus

The ability of intrahippocampal grafts of fetal septal-diagonal band tissue, rich in developing cholinergic neurons, to ameliorate cognitive impairments induced by bilateral fimbria-fornix transections in rats was examined in three experiments using the Morris water-maze to test different aspects of spatial memory. Experiment 1. Rats with fimbriafornix lesions received either septal cell suspensio

Grafted septal neurons form cholinergic synaptic connections in the dentate gyrus of behaviorally impaired aged rats

A group of aged, behaviorally impaired rats received suspension grafts of fetal septal-diagonal band tissue into the otherwise intact hippocampal formation. Three months after grafting, behaviorally recovered rats were studied by immunocytochemistry by using monoclonal antibodies to choline acetyltransferase (ChAT) and electron microscopy. The innervation of the host dentate gyrus by graft-derived

Behavioural effects of human fetal dopamine neurons grafted in a rat model of Parkinson's disease

The ventral mesencephalon, containing the developing dopaminergic neurons of the substantia nigra-ventral tegmental region, was obtained from aborted human fetuses of 9-19 weeks of gestation. The tissue was grafted into the striatum of rats previously subjected to a 6-hydroxydopamine lesion of the mesostriatal dopamine pathway. The graft recipients were immunosuppressed by daily injections of Cycl

Cyclosporin A increases survival of cross-species intrastriatal grafts of embryonic dopamine-containing neurons

The survival and function of cross-species (mouse-to-rat) grafts of fetal mesencephalic dopamine (DA) neurons, implanted as a cell suspension in the striatum of rats with lesions of the mesostriatal DA system, have been studied in animals with and without immunosuppression induced by Cyclosporin A (CyA). At 6 weeks after grafting 3 out of 7 non-CyA treated animals showed some degree of graft survi

Material Differentiations of Territoriality in Spaces of Consumption - Case studies of open-air markets in London

The aim of the paper is to investigate how material form and territorial complexity support and differentiate social interaction in urban consumption spaces. Spaces of consumption may well be the most socially mixed spaces in modern cities. Open-air markets provide excellent conditions to study these issues since they represent a broad, and often condensed, range of public situations in a consumpt

Human fetal dopamine neurons grafted in a rat model of Parkinson's disease : ultrastructural evidence for synapse formation using tyrosine hydroxylase immunocytochemistry

Human fetal mesencephalic dopamine (DA) neurons, obtained from 6.5-9 week old aborted fetuses, were grafted to the striatum of immunosuppressed rats with 6-hydroxydopamine lesions of the ascending mesostriatal DA pathway. The effects on amphetamine-induced motor asymmetry were studied at various timepoints after grafting. At eight weeks, functional graft effects were not evident but after 11 weeks

Novel differentially expressed genes induced by kainic acid in hippocampus : putative molecular effectors of plasticity and injury

Systemic kainic acid administration in rats induces acute limbic status epilepticus and subsequent neuronal degeneration and development of chronic hyperexcitability with similarities to human temporal lobe epilepsy. The mechanisms mediating the responses to kainic acid likely involve transcriptional changes in genes of importance for cellular injury, protection, and plasticity. We have used an ar

Characteristics of postischemic seizures in hyperglycemic rats

Normoglycemic animals subjected to 10-20 min of transient ischemia survive without major neurological symptoms, but incur delayed neuronal damage selectively affecting vulnerable neuronal populations. If the animals are hyperglycemic before ischemia is induced, cell damage develops more rapidly, and postischemic seizures appear after a delay of 18-24 h. This study was designed to assess whether th

Differential regulation of N-methyl-D-aspartate receptor subunit messenger RNAs in kindling-induced epileptogenesis

N-methyl-D-aspartate-receptors are implicated in several neuropathological conditions including epilepsy. As a model of complex partial seizures, rapid hippocampal kindling was chosen to investigate changes in the expression of messenger RNAs encoding the N-methyl-D-aspartate-receptor subunits NR1, NR2A and NR2B both during and in the period immediately following the induction of the kindled state

Rapid increase of BDNF mRNA levels in cortical neurons following spreading depression : regulation by glutamatergic mechanisms independent of seizure activity

Levels of mRNA for nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3) and the tyrosine kinase receptors trkB and trkC have been studied using in situ hybridization in the rat brain after topical application of KCl to the cortical surface (which induces spreading depression). Repeated episodes of spreading depression during 2 h caused a rapid and marked incre

Coexpression of neurotrophins and their receptors in neurons of the central nervous system

Nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) are neuronal survival molecules which utilize the Trk family of tyrosine kinase receptors. Using double-label in situ hybridization, we demonstrate that mRNAs for BDNF and its high-affinity receptor TrkB are coexpressed in hippocampal and cortical neurons. Also, a large number of neurons in these areas coexpress NGF and BDNF mR

Specific functions of grafted locus coeruleus neurons in the kindling model of epilepsy

Grafts of fetal noradrenaline (NA)-rich locus coeruleus (LC) tissue implanted bilaterally into the hippocampus in 6-hydroxydopamine (6-OHDA) treated, hyperexcitable rats retard seizure development in hippocampal kindling. We report that bilateral intrahippocampal LC grafts failed to affect the severity of seizures when implanted in 6-OHDA-treated, already kindled rats. Furthermore, a noradrenergic

Increased production of the TrkB protein tyrosine kinase receptor after brain insults

The protein-tyrosine kinases Trk, TrkB, and TrkC are signal-transducing receptors for a family of neurotrophic factors known as the neurotrophins. Here we show that seizures induced by hippocampal kindling lead to a rapid, transient increase of trkB mRNA and protein in the hippocampus. TrkB is a component of a high affinity receptor for brain-derived neurotrophic factor (BDNF). No change was detec

Widespread increase of nerve growth factor protein in the rat forebrain after kindling-induced seizures

Nerve growth factor (NGF) protein levels were determined in various forebrain regions using a two-site immunoassay following kindling-induced seizures. In the dentate gyrus the NGF content was significantly elevated 7 days after the last seizure (to 152% of control). In the piriform and parietal cortices, maximal increases were seen at 12 h (to 261% of control) and at 24 h (to 169% of control), re