Calcium permeable AMPA receptor-dependent long lasting plasticity of intrinsic excitability in fast spiking interneurons of the dentate gyrus decreases inhibition in the granule cell layer

Hippocampus ◽  
2014 ◽  
Vol 25 (3) ◽  
pp. 269-285 ◽  
Author(s):  
Debanjan Dasgupta ◽  
Sujit Kumar Sikdar
Keyword(s):  
Dentate Gyrus ◽  
Ampa Receptor ◽  
Granule Cell ◽  
Cell Layer ◽  
Granule Cell Layer ◽  
Intrinsic Excitability ◽  
Fast Spiking

Dentate Gyrus Immaturity in Schizophrenia

2019 ◽  
Vol 25 (6) ◽  
pp. 528-547 ◽  
Author(s):  
Ayda Tavitian ◽  
Wei Song ◽  
Hyman M. Schipper
Keyword(s):  
Animal Models ◽  
Dentate Gyrus ◽  
Granule Cell ◽  
Cell Layer ◽  
Current Theory ◽  
Position Paper ◽  
Granule Cell Layer ◽  
Molecular Profile ◽  
Rodent Models

Hippocampal abnormalities have been heavily implicated in the pathophysiology of schizophrenia. The dentate gyrus of the hippocampus was shown to manifest an immature molecular profile in schizophrenia subjects, as well as in various animal models of the disorder. In this position paper, we advance a hypothesis that this immature molecular profile is accompanied by an identifiable immature morphology of the dentate gyrus granule cell layer. We adduce evidence for arrested maturation of the dentate gyrus in the human schizophrenia-affected brain, as well as multiple rodent models of the disease. Implications of this neurohistopathological signature for current theory regarding the development of schizophrenia are discussed.

Sex difference and laterality in the volume of mouse dentate gyrus granule cell layer

1999 ◽  
Vol 827 (1-2) ◽  
pp. 41-45 ◽  
Author(s):  
Golnaz Tabibnia ◽  
Bradley M. Cooke ◽  
S.Marc Breedlove
Keyword(s):  
Dentate Gyrus ◽  
Sex Difference ◽  
Granule Cell ◽  
Cell Layer ◽  
Granule Cell Layer

GABAergic synaptic boutons in the granule cell layer of rat dentate gyrus

1984 ◽  
Vol 293 (2) ◽  
pp. 353-359 ◽  
Author(s):  
Toshio Kosaka ◽  
Kiyoshi Hama ◽  
Jang-Yen Wu
Keyword(s):  
Dentate Gyrus ◽  
Granule Cell ◽  
Cell Layer ◽  
Granule Cell Layer ◽  
Synaptic Boutons

Morpho-functional characterization of neuronal cells at different stages of maturation in granule cell layer of adult rat dentate gyrus

2004 ◽  
Vol 1017 (1-2) ◽  
pp. 21-31 ◽  
Author(s):  
Patrizia Ambrogini ◽  
Davide Lattanzi ◽  
Stefano Ciuffoli ◽  
Deborah Agostini ◽  
Luana Bertini ◽  
...  
Keyword(s):  
Dentate Gyrus ◽  
Granule Cell ◽  
Cell Layer ◽  
Functional Characterization ◽  
Neuronal Cells ◽  
Granule Cell Layer ◽  
Adult Rat

Altered synaptic transmission in dentate gyrus of rats reared in complex environments: evidence from hippocampal slices maintained in vitro

1986 ◽  
Vol 55 (4) ◽  
pp. 739-750 ◽  
Author(s):  
E. J. Green ◽  
W. T. Greenough
Keyword(s):  
Synaptic Transmission ◽  
Dentate Gyrus ◽  
Granule Cell ◽  
Granule Cells ◽  
Cell Layer ◽  
Molecular Layer ◽  
Hippocampal Slices ◽  
Granule Cell Layer ◽  
Complex Environments ◽  
Rearing Environment

Pre- and postsynaptic responses to activation of medial perforant path (MPP) axons were examined in hippocampal slices taken from rats reared for 3-4 wk in relatively complex (EC) or individual cage (IC) environments. Three types of extracellular field potentials were recorded in the infrapyramidal blade of the dentate gyrus: 1) granule cell population spikes (PSs), which reflect the number and synchrony of discharging granule cells (2), 2) population excitatory postsynaptic potentials (EPSPs), which reflect the amount of excitatory synaptic current flow into dendrites (28), and 3) presynaptic fiber volleys (FVs), which reflect the number of activated axons (28). Stimulation of the MPP evoked significantly larger PSs in slices taken from EC rats. There was no significant effect of rearing environment on PS/EPSP relationships. The slopes of EPSPs recorded at the site of synaptic activation in the dentate molecular layer and at the major current source in the dentate granule cell layer were significantly greater in slices taken from EC rats. The presynaptic FV was recorded at the site of synaptic activation in the molecular layer. FV amplitude did not differ significantly as a function of rearing environment. To examine possible differences in tissue impedance, granule cells were activated by stimulating granule cell axons in the dentate hilus and recording the antidromic PS in the granule cell layer. Antidromic PS amplitude was not significantly affected by rearing environment. The relative permanence of the experience-dependent alterations in synaptic transmission was assessed by comparing slices taken from rats that had been reared for 4 wk in complex environments followed by 3-4 wk in individual cages with those from rats reared for 7-8 wk in individual cages. There were no significant differences in MPP synaptic transmission between these groups of animals. The results suggest that experience in a relatively complex environment is associated with greater MPP synaptic transmission arising from an increased synaptic input to granule cells; the greater MPP synaptic transmission associated with behavioral experience can occur independent of behavioral state, influences from extrahippocampal brain regions and intrahippocampal inhibitory activity; and the experience-dependent synaptic alterations in the dentate gyrus are transient, in contrast to experience-dependent morphological alterations described in occipital cortex. The possible relationship of these alterations to the phenomenon of long-term enhancement is discussed.

Excitatory Synaptic Input to Granule Cells Increases With Time After Kainate Treatment

2001 ◽  
Vol 85 (3) ◽  
pp. 1067-1077 ◽  
Author(s):  
Jean-Pierre Wuarin ◽  
F. Edward Dudek
Keyword(s):  
Dentate Gyrus ◽  
Granule Cell ◽  
Synaptic Input ◽  
Granule Cells ◽  
Flash Photolysis ◽  
Cell Layer ◽  
Mossy Fiber ◽  
Hippocampal Slices ◽  
Granule Cell Layer ◽  
Excitatory Synaptic Input

Temporal lobe epilepsy is usually associated with a latent period and an increased seizure frequency following a precipitating insult. After kainate treatment, the mossy fibers of the dentate gyrus are hypothesized to form recurrent excitatory circuits between granule cells, thus leading to a progressive increase in the excitatory input to granule cells. Three groups of animals were studied as a function of time after kainate treatment: 1–2 wk, 2–4 wk, and 10–51 wk. All the animals studied 10–51 wk after kainate treatment were observed to have repetitive spontaneous seizures. Whole cell patch-clamp recordings in hippocampal slices showed that the amplitude and frequency of spontaneous excitatory postsynaptic currents (EPSCs) in granule cells increased with time after kainate treatment. This increased excitatory synaptic input was correlated with the intensity of the Timm stain in the inner molecular layer (IML). Flash photolysis of caged glutamate applied in the granule cell layer evoked repetitive EPSCs in 10, 32, and 66% of the granule cells at the different times after kainate treatment. When inhibition was reduced with bicuculline, photostimulation of the granule cell layer evoked epileptiform bursts of action potentials only in granule cells from rats 10–51 wk after kainate treatment. These data support the hypothesis that kainate-induced mossy fiber sprouting in the IML results in the progressive formation of aberrant excitatory connections between granule cells. They also suggest that the probability of occurrence of electrographic seizures in the dentate gyrus increases with time after kainate treatment.

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