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

10.7287/peerj.preprints.562 ◽

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.

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

10.21203/rs.3.rs-92512/v1 ◽

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.

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Cellular and Axonal Diversity in Molecular Layer Heterotopia of the Rat Cerebellar Vermis

BioMed Research International ◽

10.1155/2013/805467 ◽

2013 ◽

Vol 2013 ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

Sarah E. Van Dine ◽

Elsaid Salem ◽

Elizabeth George ◽

Nga Yan Siu ◽

Timothy Dotzler ◽

...

Keyword(s):

Granule Cells ◽

Cell Layer ◽

Present Report ◽

Molecular Layer ◽

Cell Types ◽

Granule Cell Layer ◽

Cerebellar Development ◽

Afferent Projections ◽

External Granule Cell Layer ◽

Primary Fissure

Molecular layer heterotopia of the cerebellar primary fissure are a characteristic of many rat strains and are hypothesized to result from defect of granule cells exiting the external granule cell layer during cerebellar development. However, the cellular and axonal constituents of these malformations remain poorly understood. In the present report, we use histochemistry and immunocytochemistry to identify neuronal, glial, and axonal classes in molecular layer heterotopia. In particular, we identify parvalbumin-expressing molecular layer interneurons in heterotopia as well as three glial cell types including Bergmann glia, Olig2-expressing oligodendrocytes, and Iba1-expressing microglia. In addition, we document the presence of myelinated, serotonergic, catecholaminergic, and cholinergic axons in heterotopia indicating possible spinal and brainstem afferent projections to heterotopic cells. These findings are relevant toward understanding the mechanisms of normal and abnormal cerebellar development.

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Trigeminal Contributions to the Dorsal Cochlear Nucleus in Mouse

Frontiers in Neuroscience ◽

10.3389/fnins.2021.715954 ◽

2021 ◽

Vol 15 ◽

Author(s):

Timothy S. Balmer ◽

Laurence O. Trussell

Keyword(s):

Cochlear Nucleus ◽

Granule Cells ◽

Auditory Pathway ◽

Dorsal Cochlear Nucleus ◽

Auditory Information ◽

Sound Sources ◽

Brush Cells ◽

Important Species ◽

Axonal Projections ◽

Auditory Signals

The dorsal cochlear nucleus (DCN) is the first site of multisensory integration in the auditory pathway of mammals. The DCN circuit integrates non-auditory information, such as head and ear position, with auditory signals, and this convergence may contribute to the ability to localize sound sources or to suppress perceptions of self-generated sounds. Several extrinsic sources of these non-auditory signals have been described in various species, and among these are first- and second-order trigeminal axonal projections. Trigeminal sensory signals from the face and ears could provide the non-auditory information that the DCN requires for its role in sound source localization and cancelation of self-generated sounds, for example, head and ear position or mouth movements that could predict the production of chewing or licking sounds. There is evidence for these axonal projections in guinea pigs and rats, although the size of the pathway is smaller than might be expected for a function essential for a prey animals’ survival. However, evidence for these projections in mice, an increasingly important species in auditory neuroscience, is lacking, raising questions about the universality of such proposed functions. We therefore investigated the presence of trigeminal projections to the DCN in mice, using viral and transgenic approaches. We found that the spinal trigeminal nucleus indeed projects to DCN, targeting granule cells and unipolar brush cells. However, direct axonal projections from the trigeminal ganglion itself were undetectable. Thus, secondary brainstem sources carry non-auditory signals to the DCN in mice that could provide a processed trigeminal signal to the DCN, but primary trigeminal afferents are not integrated directly by DCN.

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Ultrasturcture of cerebellar cells and neuropil in rats subjected to partial global cerebral ischemia

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010014227x ◽

1986 ◽

Vol 44 ◽

pp. 126-127

Author(s):

R.V.W. Dimlich ◽

M.H. Biros

Keyword(s):

Purkinje Cells ◽

Glial Cells ◽

Granule Cells ◽

Molecular Layer ◽

Cell Types ◽

Primary Objective ◽

Global Cerebral Ischemia ◽

Forebrain Ischemia ◽

Substantial Evidence ◽

Cerebellar Cells

Although a previous study in this laboratory determined that Purkinje cells of the rat cerebellum did not appear to be damaged following 30 min of forebrain ischemia followed by 30 min of reperfusion, it was suggested that an increase in rough endoplasmic reticulum (RER) and/or polysomes had occurred in these cells. The primary objective of the present study was to morphometrically determine whether or not this increase had occurred. In addition, since there is substantial evidence that glial cells may be affected by ischemia earlier than other cell types, glial cells also were examined. To ascertain possible effects on other cerebellar components, granule cells and neuropil near Purkinje cells as well as neuropil in the molecular layer also were evaluated in this investigation.

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Effects of aging on axon terminals in the dentate molecular layer

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100128924 ◽

1987 ◽

Vol 45 ◽

pp. 928-929

Author(s):

K. Cullen-Dockstader ◽

E. Fifkova

Keyword(s):

Granule Cells ◽

Molecular Layer ◽

Age Groups ◽

Long Term Potentiation ◽

Male Rats ◽

Perforant Path ◽

Axon Terminals ◽

Fischer 344 ◽

Spatial Memory Deficit ◽

Effects Of Aging

Normal aging results in a pronounced spatial memory deficit associated with a rapid decay of long-term potentiation at the synapses between the perforant path and spines in the medial and distal thirds of the dentate molecular layer (DML), suggesting the alteration of synaptic transmission in the dentate fascia. While the number of dentate granule cells remains unchanged, and there are no obvious pathological changes in these cells associated with increasing age, the density of their axospinous contacts has been shown to decrease. There are indications that the presynaptic element is affected by senescence before the postsynaptic element, yet little attention has been given to the fine structure of the remaining axon terminals. Therefore, we studied the axon terminals of the perforant path in the DML across three age groups.5 Male rats (Fischer 344) of each age group (3, 24 and 30 months), were perfused through the aorta.

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Topography and Response Timing of Intact Cerebellum Stained With Absorbance Voltage-Sensitive Dye

Journal of Neurophysiology ◽

10.1152/jn.90766.2008 ◽

2009 ◽

Vol 101 (1) ◽

pp. 474-490 ◽

Cited By ~ 12

Author(s):

Michael E. Brown ◽

Michael Ariel

Keyword(s):

Time Course ◽

Granule Cells ◽

Physiological Activity ◽

Timing Analysis ◽

Molecular Layer ◽

Stimulus Position ◽

Voltage Sensitive Dye ◽

Limited Region ◽

Response Timing

Physiological activity of the turtle cerebellar cortex (Cb), maintained in vitro, was recorded during microstimulation of inferior olive (IO). Previous single-electrode responses to such stimulation showed similar latencies across a limited region of Cb, yet those recordings lacked spatial and temporal resolution and the recording depth was variable. The topography and timing of those responses were reexamined using photodiode optical recordings. Because turtle Cb is thin and unfoliated, its entire surface can be stained by a voltage-sensitive dye and transilluminated to measure changes in its local absorbance. Microstimulation of the IO evoked widespread depolarization from the rostral to the caudal edge of the contralateral Cb. The time course of responses measured at a single photodiode matched that of single-microelectrode responses in the corresponding Cb locus. The largest and most readily evoked response was a sagittal band centered about 0.7 mm from the midline. Focal white-matter (WM) microstimulation on the ventricular surface also activated sagittal bands, whereas stimulation of adjacent granule cells evoked a radial patch of activation. In contrast, molecular-layer (ML) microstimulation evoked transverse beams of activation, centered on the rostrocaudal stimulus position, which traveled bidirectionally across the midline to the lateral edges of the Cb. A timing analysis demonstrated that both IO and WM microstimulation evoked responses with a nearly simultaneous onset along a sagittal band, whereas ML microstimulation evoked a slowly propagating wave traveling about 25 cm/s. The response similarity to IO and WM microstimulation suggests that the responses to WM microstimulation are dominated by activation of its climbing fibers. The Cb's role in the generation of precise motor control may result from these temporal and topographic differences in orthogonally oriented pathways. Optical recordings of the turtle's thin flat Cb can provide insights into that role.

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