Repeated neonatal separation stress alters the composition of neurochemically characterized interneuron subpopulations in the rodent dentate gyrus and basolateral amygdala

2008 ◽  
Vol 68 (9) ◽  
pp. 1137-1152 ◽  
Author(s):  
Katja Seidel ◽  
Carina Helmeke ◽  
Gerd Poeggel ◽  
Katharina Braun
Keyword(s):  
Dentate Gyrus ◽  
Basolateral Amygdala ◽  
Neonatal Separation

scholarly journals Reduced GluN1 in mouse dentate gyrus is associated with CA3 hyperactivity and psychosis-like behaviors

2018 ◽  
Vol 25 (11) ◽  
pp. 2832-2843 ◽  
Author(s):  
Amir Segev ◽  
Masaya Yanagi ◽  
Daniel Scott ◽  
Sarah A. Southcott ◽  
Jacob M. Lister ◽  
...  
Keyword(s):  
Dentate Gyrus ◽  
Basolateral Amygdala ◽  
Pyramidal Neurons ◽  
Mossy Fibers ◽  
Model Systems ◽  
Memory Processing ◽  
Hippocampal Subfields ◽  
Whole Cell Patch Clamp ◽  
Hippocampal Activity

Abstract Recent findings from in vivo-imaging and human post-mortem tissue studies in schizophrenic psychosis (SzP), have demonstrated functional and molecular changes in hippocampal subfields that can be associated with hippocampal hyperexcitability. In this study, we used a subfield-specific GluN1 knockout mouse with a disease-like molecular perturbation expressed only in hippocampal dentate gyrus (DG) and assessed its association with hippocampal physiology and psychosis-like behaviors. First, we used whole-cell patch-clamp recordings to measure the physiological changes in hippocampal subfields and cFos immunohistochemistry to examine cellular excitability. DG-GluN1 KO mice show CA3 cellular hyperactivity, detected using two approaches: (1) increased excitatory glutamate transmission at mossy fibers (MF)-CA3 synapses, and (2) an increased number of cFos-activated pyramidal neurons in CA3, an outcome that appears to project downstream to CA1 and basolateral amygdala (BLA). Furthermore, we examined psychosis-like behaviors and pathological memory processing; these show an increase in fear conditioning (FC), a reduction in prepulse inhibition (PPI) in the KO animal, along with a deterioration in memory accuracy with Morris Water Maze (MWM) and reduced social memory (SM). Moreover, with DREADD vectors, we demonstrate a remarkably similar behavioral profile when we induce CA3 hyperactivity. These hippocampal subfield changes could provide the basis for the observed increase in human hippocampal activity in SzP, based on the shared DG-specific GluN1 reduction. With further characterization, these animal model systems may serve as targets to test psychosis mechanisms related to hippocampus and assess potential hippocampus-directed treatments.

Lesioning the fimbria–fornix impairs basolateral amygdala induced reinforcement of LTP in the dentate gyrus

2000 ◽  
Vol 861 (1) ◽  
pp. 186-189 ◽  
Author(s):  
J. Jas ◽  
W. Almaguer ◽  
J.U. Frey ◽  
J. Bergado
Keyword(s):  
Dentate Gyrus ◽  
Basolateral Amygdala

Effect of isolation rearing on the expression of AMPA glutamate receptors in the hippocampal formation

2010 ◽  
Vol 25 (12) ◽  
pp. 1720-1729 ◽  
Author(s):  
Rodrigo S Sestito ◽  
Lucas B Trindade ◽  
Rodrigo G de Souza ◽  
Lucila N Kerbauy ◽  
Melina M Iyomasa ◽  
...  
Keyword(s):  
Dentate Gyrus ◽  
Glutamate Receptors ◽  
Entorhinal Cortex ◽  
Ampa Receptors ◽  
Basolateral Amygdala ◽  
Hippocampal Formation ◽  
Apparent Difference ◽  
Isolation Rearing ◽  
Ampa Glutamate Receptors ◽  
Glutamatergic Signaling

Reduced glutamatergic signaling may contribute to cognitive dysfunction in schizophrenia. Glutamatergic synapses might be the site of primary abnormalities in this disorder with the dopaminergic changes being secondary to altered glutamatergic transmission. Isolation rearing of rats from weaning has been used as an experimental model for affective disorders like schizophrenia. In this immunohistochemistry study we evaluate the changes in the expression of GluR1 and GluR2 AMPA receptors in the hippocampus, amygdala and entorhinal cortex induced by isolation rearing. Two groups of Wistar rats (grouped and isolated, n = 6/each) were used. Isolation rearing induced a significant decrease in GluR1- and GluR2-immunopositive cells in the hippocampus. For GluR1 the reduction was 31% in the hilus of dentate gyrus ( p = 0.02) and 47% in CA3 ( p = 0.002). For GluR2 the reduction was 52% in the hilus of dentate gyrus ( p < 0.0001) and 29% in CA1 ( p = 0.002). Isolation rearing induced a non-significant decrease in GluR1-immunopositive cells in the basolateral amygdala ( p = 0.066) while no alteration was found in the lateral nucleus ( p = 0.657). For GluR2 no changes were induced by isolation in both nuclei of the amygdala. In the entorhinal cortex no apparent difference was seen in GluR1- or GluR2-immunopositive cells when isolated reared rats were compared to grouped rats. The results suggest that isolation rearing from weaning induces changes on the expression of AMPA glutamate receptors in the hippocampus similar to those reported for postmortem human brains with schizophrenia. These findings also contribute to additional evidence for using isolation rearing of rats from weaning as an animal model for schizophrenia.

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