scholarly journals Postnatal Developmental Expression Profile Classifies the Indusium Griseum as a Distinct Subfield of the Hippocampal Formation

2021 ◽  
Vol 8 ◽  
Author(s):  
Marie Sanders ◽  
Elisabeth Petrasch-Parwez ◽  
Hans-Werner Habbes ◽  
Monika v. Düring ◽  
Eckart Förster
Keyword(s):  
Cell Fate ◽  
Calcium Binding ◽  
Time Course ◽  
Fluorescent Protein ◽  
Granule Cells ◽  
Hippocampal Formation ◽  
Developmental Expression ◽  
Dentate Granule Cell ◽  
Transgenic Mouse Line ◽  
Dentate Granule Cells

The indusium griseum (IG) is a cortical structure overlying the corpus callosum along its anterior–posterior extent. It has been classified either as a vestige of the hippocampus or as an extension of the dentate gyrus via the fasciola cinerea, but its attribution to a specific hippocampal subregion is still under debate. To specify the identity of IG neurons more precisely, we investigated the spatiotemporal expression of calbindin, secretagogin, Necab2, PCP4, and Prox1 in the postnatal mouse IG, fasciola cinerea, and hippocampus. We identified the calcium-binding protein Necab2 as a first reliable marker for the IG and fasciola cinerea throughout postnatal development into adulthood. In contrast, calbindin, secretagogin, and PCP4 were expressed each with a different individual time course during maturation, and at no time point, IG or fasciola cinerea principal neurons expressed Prox1, a transcription factor known to define dentate granule cell fate. Concordantly, in a transgenic mouse line expressing enhanced green fluorescent protein (eGFP) in dentate granule cells, neurons of IG and fasciola cinerea were eGFP-negative. Our findings preclude that IG neurons represent dentate granule cells, as earlier hypothesized, and strongly support the view that the IG is an own hippocampal subfield composed of a distinct neuronal population.

The chemokine SDF1 regulates migration of dentate granule cells

Development ◽  
2002 ◽  
Vol 129 (18) ◽  
pp. 4249-4260 ◽  
Author(s):  
Anil Bagri ◽  
Theresa Gurney ◽  
Xiaoping He ◽  
Yong-Rui Zou ◽  
Dan R. Littman ◽  
...  
Keyword(s):  
Cell Migration ◽  
Dentate Gyrus ◽  
Granule Cell ◽  
Granule Cells ◽  
Ectopic Expression ◽  
Dentate Granule Cell ◽  
Vitro Assay ◽  
Dentate Granule Cells ◽  
Cell Position

The dentate gyrus is the primary afferent pathway into the hippocampus, but there is little information concerning the molecular influences that govern its formation. In particular, the control of migration and cell positioning of dentate granule cells is not clear. We have characterized more fully the timing and route of granule cell migration during embryogenesis using in utero retroviral injections. Using this information, we developed an in vitro assay that faithfully recapitulates important events in dentate gyrus morphogenesis. In searching for candidate ligands that may regulate dentate granule cell migration, we found that SDF1, a chemokine that regulates cerebellar and leukocyte migration, and its receptor CXCR4 are expressed in patterns that suggest a role in dentate granule cell migration. Furthermore, CXCR4 mutant mice have a defect in granule cell position. Ectopic expression of SDF1 in our explant assay showed that it directly regulates dentate granule cell migration. Our study shows that a chemokine is necessary for the normal development of the dentate gyrus, a forebrain structure crucial for learning and memory.

Physiological Properties of GABAA Receptors From Acutely Dissociated Rat Dentate Granule Cells

1999 ◽  
Vol 81 (5) ◽  
pp. 2464-2471 ◽  
Author(s):  
Jaideep Kapur ◽  
Kevin F. Haas ◽  
Robert L. Macdonald
Keyword(s):  
Gabaa Receptors ◽  
Time Course ◽  
Granule Cells ◽  
Whole Cell ◽  
Dentate Granule Cells ◽  
Physiological Properties ◽  
Current Activation ◽  
Cell Current ◽  
Old Rats ◽  
Activation Rates

Physiological properties of GABAA receptors from acutely dissociated rat dentate granule cells. Study of fast, GABAA receptor-mediated, inhibitory postsynaptic currents (IPSCs) in hippocampal dentate granule cells has suggested that properties of GABAA receptors influence the amplitude and time course of the IPSCs. This study describes the physiological properties of GABAA receptors present on hippocampal dentate granule cells acutely isolated from 18- to 35-day-old rats. Rapid application of 1 mM GABA to outside-out macropatches excised from granule cells produced GABAA receptor currents with rapid rise time and biexponential decay of current after removal of GABA. After activation, granule cell GABAA receptor currents desensitized incompletely. During a 400-ms application of 1 mM GABA, peak current only desensitized ∼40%. In symmetrical chloride solutions there was no outward rectification of whole cell current. Activation rates and peak currents elicited by rapid application of GABA to macropatches were also similar at positive and negative holding potentials. However, deactivation of GABAA receptor currents was slower at positive holding potentials. When whole cell currents were recorded without ATP in the pipette, current run-down was not apparent for 30 min in 50% of neurons, but run-down appeared to start soon after access was established in the remaining neurons. When 2 mM ATP was included in the recording pipette no run-down was apparent in 30 min of recording. The efficacy and potency of GABA were lower in cells recorded with no ATP in the pipette and during run-down compared with those recorded with 2 mM ATP and no run-down.

scholarly journals Genetic targeting and physiological features of VGLUT3+ amacrine cells

2011 ◽  
Vol 28 (5) ◽  
pp. 381-392 ◽  
Author(s):  
WILLIAM N. GRIMES ◽  
REBECCA P. SEAL ◽  
NICHOLAS OESCH ◽  
ROBERT H. EDWARDS ◽  
JEFFREY S. DIAMOND
Keyword(s):  
Time Course ◽  
Fluorescent Protein ◽  
Yellow Fluorescent Protein ◽  
Glutamate Transporter ◽  
Amacrine Cells ◽  
Bipolar Cells ◽  
Membrane Properties ◽  
Visual Signal ◽  
Transgenic Mouse Line ◽  
Electrophysiological Recordings

AbstractAmacrine cells constitute a diverse class of interneurons that contribute to visual signal processing in the inner retina, but surprisingly, little is known about the physiology of most amacrine cell subtypes. Here, we have taken advantage of the sparse expression of vesicular glutamate transporter 3 (VGLUT3) in the mammalian retina to target the expression of yellow fluorescent protein (YFP) to a unique population of amacrine cells using a new transgenic mouse line. Electrophysiological recordings made from YFP-positive (VGLUT3+) amacrine cells provide the first functional data regarding the active membrane properties and synaptic connections of this recently identified cell type. We found that VGLUT3+ amacrine cells receive direct synaptic input from bipolar cells via both N-methyl-d-aspartate receptors (NMDARs) and non-NMDARs. Voltage-gated sodium channels amplified these excitatory inputs but repetitive spiking was never observed. VGLUT3+ amacrine cells responded transiently to both light increments (ON response) and decrements (OFF response); ON responses consisted exclusively of inhibitory inputs, while OFF responses comprised both excitatory and inhibitory components, although the inhibitory conductance was larger in amplitude and longer in time course. The physiological properties and anatomical features of the VGLUT3+ amacrine cells suggest that this bistratified interneuron may play a role in disinhibitory signaling and/or crossover inhibition between parallel pathways in the retina.

scholarly journals The role of afferent activity in the maintenance of primate neocorticalfunction

1990 ◽  
Vol 153 (1) ◽  
pp. 155-176 ◽  
Author(s):  
E. G. Jones
Keyword(s):  
Gene Expression ◽  
Calcium Binding ◽  
Time Course ◽  
Developmental Expression ◽  
Acid Decarboxylase ◽  
Mrna Levels ◽  
Gamma Aminobutyric Acid ◽  
Afferent Activity ◽  
S1 Nuclease ◽  
Activity Dependent

The major neuronal populations of the primate cerebral cortex can be classified immunocytochemically according to their transmitters and in terms of the differential expression of certain other molecules such as neuropeptides, calcium-binding proteins and protein kinases. We have been able to chart the time course of developmental expression of these molecules and to show that gene expression for many of them is regulated in adult and infant animals by afferent activity entering the cortex. In the visual cortex of adult monkeys, levels of immunocytochemically detectable gamma aminobutyric acid (GABA), of its synthesizing enzyme glutamic acid decarboxylase (GAD) and of the tachykinins are greatly reduced in deprived ocular dominance columns within 24 h of blocking impulse activity in the optic nerve by intraocular injection of tetrodotoxin (TTX). Conversely, levels of immunocytochemically detectable calcium-calmodulin-dependent protein kinase (CAMII kinase) are increased in deprived eye dominance columns. These effects are quickly reversible on restoration of binocular vision, and experiments involving in situ hybridization and S1 nuclease protection assays show that the changes are associated with parallel changes in mRNA levels for preprotachykinin and CAM II kinase, but not for GAD, which appears to be regulated by post-transcriptional mechanisms. Experiments in the primate somatic sensory cortex suggest comparable activity-dependent effects on gene expression there also. It is proposed that effects of this type underlie the establishment of cortical maps during development and their activity-dependent mutability in adulthood.

scholarly journals Dentate granule cells encode auditory decisions after reinforcement learning in rats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jia Shen ◽  
Pan-Tong Yao ◽  
Shaoyu Ge ◽  
Qiaojie Xiong
Keyword(s):  
Reinforcement Learning ◽  
Granule Cells ◽  
Spatial Coding ◽  
Dentate Granule Cell ◽  
Dentate Granule Cells ◽  
Task Learning ◽  
Navigation Path ◽  
Potential Link ◽  
In Vivo Calcium Imaging

AbstractAuditory-cued goal-oriented behaviors requires the participation of cortical and subcortical brain areas, but how neural circuits associate sensory-based decisions with goal locations through learning remains poorly understood. The hippocampus is critical for spatial coding, suggesting its possible involvement in transforming sensory inputs to the goal-oriented decisions. Here, we developed an auditory discrimination task in which rats learned to navigate to goal locations based on the frequencies of auditory stimuli. Using in vivo calcium imaging in freely behaving rats over the course of learning, we found that dentate granule cells became more active, spatially tuned, and responsive to task-related variables as learning progressed. Furthermore, only after task learning, the activity of dentate granule cell ensembles represented the navigation path and predicts auditory decisions as early as when rats began to approach the goals. Finally, chemogenetic silencing of dentate gyrus suppressed task learning. Our results demonstrate that dentate granule cells gain task-relevant firing pattern through reinforcement learning and could be a potential link of sensory decisions to spatial navigation.

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