Intrinsic heterogeneity of mossy cells mediates the differential crosstalk between the dorsal and ventral hippocampus

2020 ◽  
Author(s):  
Minseok Jeong ◽  
Jin-Hyeok Jang ◽  
Seo-Jin Oh ◽  
Young-Shik Choe ◽  
Jeongrak Park ◽  
...  
Keyword(s):  
Axon Guidance ◽  
Granule Cells ◽  
Transcriptional Profiling ◽  
Longitudinal Axis ◽  
Functional Differentiation ◽  
Dorsoventral Axis ◽  
Mossy Cells ◽  
Axonal Projections ◽  
Molecular Layers ◽  
External Stimuli

Abstract Glutamatergic mossy cells (MCs) are responsible for the associational and commissural connectivity of the dentate gyrus. MCs are widely distributed along the dorsoventral axis, but potential heterogeneity within MCs is scarcely explored. Here, we showed that MCs consist of two subpopulations which differ in their neuronal properties and functions. We discovered that MCs, depending on their dorsoventral location, extend distinct axonal projections in the molecular layers. Comparative transcriptional profiling of dorsal and ventral MCs revealed different neurobiological characteristics in axon guidance and synapse assembly. Despite common activation by external stimuli, dorsal MCs, but not ventral MCs, provide net inhibitory control on granule cells across the longitudinal axis. Furthermore, dorsal MC inhibition, unlikely that of ventral MCs, increases behavioral anxiety and disables rapid contextual discrimination. Collectively, dorsoventral heterogeneity of MCs may provide a novel mechanism for functional differentiation as well as distinct association along the longitudinal extent of the hippocampus.

scholarly journals Ventral hippocampal mossy cell hyperactivity degrades dorsal hippocampal mnemonic function via longitudinal projections

2020 ◽  
Author(s):  
James P Bauer ◽  
Sarah L Rader ◽  
Max Joffe ◽  
Wooseok Kwon ◽  
Juliana Quay ◽  
...  
Keyword(s):  
Dentate Gyrus ◽  
Granule Cells ◽  
Memory Task ◽  
Longitudinal Axis ◽  
Motor Behaviors ◽  
Mossy Cells ◽  
Object Location Memory ◽  
Dorsal Hippocampal ◽  
Mossy Cell

The anterior hippocampus of individuals with early psychosis or schizophrenia is hyperactive compared to healthy controls. In rodent models of schizophrenia etiology, the ventral hippocampus, analogous to the human anterior hippocampus, is also hyperactive with effects on extrahippocampal neural circuits that might contribute to positive, negative, and cognitive symptoms. Less is known about how anterior hippocampal hyperactivity might directly influence intrahippocampal function across the structure's longitudinal axis. This question is important for understanding cognitive dysfunction in schizophrenia, which includes deficits attributed to both the anterior and posterior hippocampus. We hypothesized that hyperactivity of ventral hippocampal mossy cells, which send dense longitudinal projections throughout the hippocampal longitudinal axis, may be sufficient to disrupt spatial memory encoding, a dorsal hippocampal-dependent function. Using an intersectional viral strategy, we targeted ventral mossy cells projecting to the dorsal dentate gyrus. In vivo fiber photometry revealed these cells were activated during behavior related to context mapping but not during non-exploratory motor behaviors. Anterograde transsynaptic tracing and optogenetic terminal stimulation revealed functional connectivity between ventral mossy cells and dorsal dentate gyrus granule cells. Finally, chemogenetic activation of ventral mossy cells during the encoding phase of an object location memory task impaired retrieval 24 hours later, without effects on locomotion or other exploratory behaviors. These findings suggest that anterior hippocampal hyperactivity may have intrahippocampal consequences to degrade posterior hippocampal function and support future studies engaging this circuit target to mitigate specific cognitive deficits associated with schizophrenia.

scholarly journals Brainstem projections to molecular layer heterotopia of the cerebellar vermis: Evidence from the Allen Mouse Brain Connectivity Database

2014 ◽  
Author(s):  
Raddy L Ramos
Keyword(s):  
Granule Cells ◽  
Vestibular Nucleus ◽  
Brain Connectivity ◽  
Present Report ◽  
Molecular Layer ◽  
Dorsal Cochlear Nucleus ◽  
Cerebellar Vermis ◽  
Axonal Projections ◽  
Viii And Ix ◽  
Molecular Layers

Molecular layer heterotopia of the cerebellar vermis are a characteristic feature of C57BL/6 mice. Heterotopia consist of neurons and glia in the molecular layers between folia VIII and IX in regions lacking pia. Previously, we described the cellular composition of heterotopia which includes granule cells, Purkinje cells, Golgi cells, etc. However, the axonal constituents and afferent connections of these malformations remain poorly understood. In the present report axonal projections to heterotopia are documented from diverse brainstem nuclei such as the spinal vestibular nucleus, dorsal cochlear nucleus, and nucleus prepositus. These findings are relevant toward understanding the mechanisms of normal and abnormal cerebellar development and the establishment of cerebellar circuits.

scholarly journals Brainstem projections to molecular layer heterotopia of the cerebellar vermis: Evidence from the Allen Mouse Brain Connectivity Database

2014 ◽  
Author(s):  
Raddy L Ramos
Keyword(s):  
Granule Cells ◽  
Vestibular Nucleus ◽  
Brain Connectivity ◽  
Present Report ◽  
Molecular Layer ◽  
Dorsal Cochlear Nucleus ◽  
Cerebellar Vermis ◽  
Axonal Projections ◽  
Viii And Ix ◽  
Molecular Layers

Molecular layer heterotopia of the cerebellar vermis are a characteristic feature of C57BL/6 mice. Heterotopia consist of neurons and glia in the molecular layers between folia VIII and IX in regions lacking pia. Previously, we described the cellular composition of heterotopia which includes granule cells, Purkinje cells, Golgi cells, etc. However, the axonal constituents and afferent connections of these malformations remain poorly understood. In the present report axonal projections to heterotopia are documented from diverse brainstem nuclei such as the spinal vestibular nucleus, dorsal cochlear nucleus, and nucleus prepositus. These findings are relevant toward understanding the mechanisms of normal and abnormal cerebellar development and the establishment of cerebellar circuits.

Vestibular Signals in the Parasolitary Nucleus

2000 ◽  
Vol 83 (6) ◽  
pp. 3559-3569 ◽  
Author(s):  
N. H. Barmack ◽  
V. Yakhnitsa
Keyword(s):  
Inferior Olive ◽  
Granule Cells ◽  
Vestibular Nucleus ◽  
Semicircular Canals ◽  
Longitudinal Axis ◽  
Vestibular Stimulation ◽  
Primary Afferents ◽  
Climbing Fiber ◽  
Large Sphere ◽  
Optimal Response

Vestibular primary afferents project to secondary vestibular neurons located in the vestibular complex. Vestibular primary afferents also project to the uvula-nodulus of the cerebellum where they terminate on granule cells. In this report we describe the physiological properties of neurons in a “new” vestibular nucleus, the parasolitary nucleus (Psol). This nucleus consists of 2,300 GABAergic neurons that project onto the ipsilateral inferior olive (β-nucleus and dorsomedial cell column) as well as the nucleus reticularis gigantocellularis. These olivary neurons are the exclusive source of vestibularly modulated climbing fiber inputs to the cerebellum. We recorded the activity of Psol neurons during natural vestibular stimulation in anesthetized rabbits. The rabbits were placed in a three-axis rate table at the center of a large sphere, permitting vestibular and optokinetic stimulation. We recorded from 74 neurons in the Psol and from 23 neurons in the regions bordering Psol. The activity of 72/74 Psol neurons and 4/23 non-Psol neurons was modulated by vestibular stimulation in either the pitch or roll planes but not the horizontal plane. Psol neurons responded in phase with ipsilateral side-down head position or velocity during sinusoidal stimulation. Approximately 80% of the recorded Psol neurons responded to static roll-tilt. The optimal response planes of evoked vestibular responses were inferred from measurement of null planes. Optimal response planes usually were aligned with the anatomical orientation of one of the two ipsilateral vertical semicircular canals. The frequency dependence of null plane measurements indicated a convergence of vestibular information from otoliths and semicircular canals. None of the recorded neurons evinced optokinetic sensitivity. These results are consistent with the view that Psol neurons provide the vestibular signals to the inferior olive that eventually reached the cerebellum in the form of modulated climbing fiber discharges. These signals provide information about spatial orientation about the longitudinal axis.

scholarly journals Transcriptomic Analysis of Leaf Sheath Maturation in Maize

2019 ◽  
Vol 20 (10) ◽  
pp. 2472 ◽  
Author(s):  
Lei Dong ◽  
Lei Qin ◽  
Xiuru Dai ◽  
Zehong Ding ◽  
Ran Bi ◽  
...  
Keyword(s):  
Leaf Blade ◽  
Crop Yields ◽  
Transcriptional Profiling ◽  
Homeobox Gene ◽  
Lignin Biosynthesis ◽  
Gene Families ◽  
Longitudinal Axis ◽  
Leaf Sheath ◽  
Morphological Development ◽  
Maize Leaf

The morphological development of the leaf greatly influences plant architecture and crop yields. The maize leaf is composed of a leaf blade, ligule and sheath. Although extensive transcriptional profiling of the tissues along the longitudinal axis of the developing maize leaf blade has been conducted, little is known about the transcriptional dynamics in sheath tissues, which play important roles in supporting the leaf blade. Using a comprehensive transcriptome dataset, we demonstrated that the leaf sheath transcriptome dynamically changes during maturation, with the construction of basic cellular structures at the earliest stages of sheath maturation with a transition to cell wall biosynthesis and modifications. The transcriptome again changes with photosynthesis and lignin biosynthesis at the last stage of sheath tissue maturation. The different tissues of the maize leaf are highly specialized in their biological functions and we identified 15 genes expressed at significantly higher levels in the leaf sheath compared with their expression in the leaf blade, including the BOP2 homologs GRMZM2G026556 and GRMZM2G022606, DOGT1 (GRMZM2G403740) and transcription factors from the B3 domain, C2H2 zinc finger and homeobox gene families, implicating these genes in sheath maturation and organ specialization.

Evidence from simultaneous intracellular recordings in rat hippocampal slices that area CA3 pyramidal cells innervate dentate hilar mossy cells

1994 ◽  
Vol 72 (5) ◽  
pp. 2167-2180 ◽  
Author(s):  
H. E. Scharfman
Keyword(s):  
Pyramidal Cell ◽  
Action Potentials ◽  
Granule Cells ◽  
Hippocampal Slices ◽  
Pyramidal Cells ◽  
Probability Of Failure ◽  
Mossy Cells ◽  
Mossy Cell ◽  
Ca3 Pyramidal Cells ◽  
Area Ca3

1. Simultaneous intracellular recordings of area CA3 pyramidal cells and dentate hilar “mossy” cells were made in rat hippocampal slices to test the hypothesis that area CA3 pyramidal cells excite mossy cells monosynaptically. Mossy cells and pyramidal cells were differentiated by location and electrophysiological characteristics. When cells were impaled near the border of area CA3 and the hilus, their identity was confirmed morphologically after injection of the marker Neurobiotin. 2. Evidence for monosynaptic excitation of a mossy cell by a pyramidal cell was obtained in 7 of 481 (1.4%) paired recordings. In these cases, a pyramidal cell action potential was followed immediately by a 0.40 to 6.75 (mean, 2.26) mV depolarization in the simultaneously recorded mossy cell (mossy cell membrane potentials, -60 to -70 mV). Given that pyramidal cells used an excitatory amino acid as a neurotransmitter (Cotman and Nadler 1987; Ottersen and Storm-Mathisen 1987) and recordings were made in the presence of the GABAA receptor antagonist bicuculline (25 microM), it is likely that the depolarizations were unitary excitatory postsynaptic potentials (EPSPs). 3. Unitary EPSPs of mossy cells were prone to apparent “failure.” The probability of failure was extremely high (up to 0.72; mean = 0.48) if the effects of all presynaptic action potentials were examined, including action potentials triggered inadvertently during other spontaneous EPSPs of the mossy cell. Probability of failure was relatively low (as low as 0; mean = 0.24) if action potentials that occurred during spontaneous activity of the mossy cell were excluded. These data suggest that unitary EPSPs produced by pyramidal cells are strongly affected by concurrent synaptic inputs to the mossy cell. 4. Unitary EPSPs were not clearly affected by manipulation of the mossy cell's membrane potential. This is consistent with the recent report that area CA3 pyramidal cells innervate distal dendrites of mossy cells (Kunkel et al. 1993). Such a distal location also may contribute to the high incidence of apparent failures. 5. Characteristics of unitary EPSPs generated by pyramidal cells were compared with the properties of the unitary EPSPs produced by granule cells. In two slices, pyramidal cell and granule cell inputs to the same mossy cell were compared. In other slices, inputs to different mossy cells were compared. In all experiments, unitary EPSPs produced by granule cells were larger in amplitude but similar in time course to unitary EPSPs produced by pyramidal cells. Probability of failure was lower and paired-pulse facilitation more common among EPSPs triggered by granule cells.(ABSTRACT TRUNCATED AT 400 WORDS)

K-dependent inhibition in the dentate-CA3 network of guinea pig hippocampal slices

1992 ◽  
Vol 68 (5) ◽  
pp. 1548-1557 ◽  
Author(s):  
U. Misgeld ◽  
M. Bijak ◽  
H. Brunner ◽  
K. Dembowsky
Keyword(s):  
Guinea Pig ◽  
Granule Cells ◽  
Hippocampal Slices ◽  
Granule Cell Layer ◽  
Postsynaptic Potentials ◽  
Burst Discharge ◽  
Mossy Cells ◽  
Discharge Activity ◽  
Dependent Inhibition ◽  
Hilar Neurons

1. The occurrence of potassium-dependent inhibitory postsynaptic potentials (K-IPSPs) in relation to burst discharges induced by 4-aminopyridine (4-AP; 30 microM) was studied in CA3, granule and hilar neurons in guinea pig hippocampal slices with the use of paired extra- and/or intracellular recording. 2. Slow small (2-5 mV) and large (up to 30 mV) K-IPSPs were observed in CA3, granule and in some hilar neurons during 4-AP applications in the presence of blockers for fast synaptic transmission, picrotoxin (50 microM), and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX; 5-10 microM). Amplitudes of K-IPSPs were linearly related to voltage, and they reversed in sign close to -100 mV, as expected for synaptic potentials generated by an increase in K-conductance. 3. In CA3 neurons, 4-AP applied in the presence of picrotoxin elicited burst discharges and K-IPSPs. CNQX blocked the burst discharge activity and increased the amplitude of K-IPSPs. 4. In granule cells, 4-AP applied in the presence of picrotoxin elicited K-IPSPs and only inconsistently small excitatory postsynaptic potentials (EPSPs). The EPSPs were blocked by CNQX, but CNQX application did not affect the K-IPSPs. However, in granule cells it could be observed that blockade of Cl-inhibition by picrotoxin in the presence of CNQX increased the amplitude of K-IPSPs. 5. In hilar neurons, 4-AP applied in the presence of picrotoxin elicited mainly burst discharges. CNQX blocked the burst discharges only in a few cells. In most hilar neurons K-IPSPs were observed at the beginning of the 4-AP effect, but subsequently K-IPSPs were replaced by burst discharges. 6. To determine the type of cells that burst in picrotoxin and 4-AP, neurons were stained intracellularly with horseradish peroxidase. Neurons stained in the granule cell layer did not burst and were morphologically identified as granule cells. Neurons stained in the hilar region burst and were nonpyramidal, nongranule cells. Bursting cells stained in the CA3 area were all pyramidal cells. 7. The hilar neurons varied considerably in size and dendritic organization. They could be classified as aspiny and spiny cells, the latter including mossy cells. 8. We conclude that K-dependent inhibition may explain the long-lasting IPSPs observed in in vivo recordings from hippocampal cells. In a hippocampal lamella, burst discharge activity of hilar neurons including presumed excitatory mossy cells is associated with inhibition of granule cells.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Tactile modulation of memory and anxiety requires dentate granule cells along the dorsoventral axis

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Chi Wang ◽  
Hui Liu ◽  
Kun Li ◽  
Zhen-Zhen Wu ◽  
Chen Wu ◽  
...  
Keyword(s):  
Life Stress ◽  
Structural Modification ◽  
Granule Cells ◽  
Early Life Stress ◽  
Memory Deficits ◽  
Dorsoventral Axis ◽  
Beneficial Effects ◽  
Cognition And Emotion ◽  
Adult Mice ◽  
Underlying Mechanisms

AbstractTouch can positively influence cognition and emotion, but the underlying mechanisms remain unclear. Here, we report that tactile experience enrichment improves memory and alleviates anxiety by remodeling neurons along the dorsoventral axis of the dentate gyrus (DG) in adult mice. Tactile enrichment induces differential activation and structural modification of neurons in the dorsal and ventral DG, and increases the presynaptic input from the lateral entorhinal cortex (LEC), which is reciprocally connected with the primary somatosensory cortex (S1), to tactile experience-activated DG neurons. Chemogenetic activation of tactile experience-tagged dorsal and ventral DG neurons enhances memory and reduces anxiety respectively, whereas inactivation of these neurons or S1-innervated LEC neurons abolishes the beneficial effects of tactile enrichment. Moreover, adulthood tactile enrichment attenuates early-life stress-induced memory deficits and anxiety-related behavior. Our findings demonstrate that enriched tactile experience retunes the pathway from S1 to DG and enhances DG neuronal plasticity to modulate cognition and emotion.

scholarly journals Spine morphogenesis in newborn granule cells is differentially regulated in the outer and middle molecular layers

2014 ◽  
Vol 522 (12) ◽  
pp. 2756-2766 ◽  
Author(s):  
Chunmei Zhao ◽  
Jessica Jou ◽  
Lisa J. Wolff ◽  
Huaiyu Sun ◽  
Fred H. Gage
Keyword(s):  
Granule Cells ◽  
Molecular Layers ◽  
Spine Morphogenesis

scholarly journals Differential ability of the dorsal and ventral rat hippocampus to exhibit group I metabotropic glutamate receptor–dependent synaptic and intrinsic plasticity

2017 ◽  
Vol 1 ◽  
pp. 239821281668979 ◽  
Author(s):  
Patrick Tidball ◽  
Hannah V. Burn ◽  
Kai Lun Teh ◽  
Arturas Volianskis ◽  
Graham L. Collingridge ◽  
...  
Keyword(s):  
Synaptic Transmission ◽  
Glutamate Receptor ◽  
Metabotropic Glutamate Receptor ◽  
Hippocampal Slices ◽  
Longitudinal Axis ◽  
Functional Differentiation ◽  
Rat Hippocampus ◽  
Metabotropic Glutamate ◽  
Group I ◽  
Intrinsic Plasticity

Background: The hippocampus is critically involved in learning and memory processes. Although once considered a relatively homogenous structure, it is now clear that the hippocampus can be divided along its longitudinal axis into functionally distinct domains, responsible for the encoding of different types of memory or behaviour. Although differences in extrinsic connectivity are likely to contribute to this functional differentiation, emerging evidence now suggests that cellular and molecular differences at the level of local hippocampal circuits may also play a role. Methods: In this study, we have used extracellular field potential recordings to compare basal input/output function and group I metabotropic glutamate receptor-dependent forms of synaptic and intrinsic plasticity in area CA1 of slices taken from the dorsal and ventral sectors of the adult rat hippocampus. Results: Using two extracellular electrodes to simultaneously record field EPSPs and population spikes, we show that dorsal and ventral hippocampal slices differ in their basal levels of excitatory synaptic transmission, paired-pulse facilitation, and EPSP-to-Spike coupling. Furthermore, we show that slices taken from the ventral hippocampus have a greater ability than their dorsal counterparts to exhibit long-term depression of synaptic transmission and EPSP-to-Spike potentiation induced by transient application of the group I mGluR agonist ( RS)-3,5-dihydroxyphenylglycine. Conclusions: Together, our results provide further evidence that the information processing properties of local hippocampal circuits differ in the dorsal and ventral hippocampal sectors, and that these differences may in turn contribute to the functional differentiation that exists along the hippocampal longitudinal axis.

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