Functional parasagittal compartments in the rat cerebellar cortex: an in vivo optical imaging study using neutral red

1996 ◽  
Vol 76 (6) ◽  
pp. 4169-4174 ◽  
Author(s):  
G. Chen ◽  
C. L. Hanson ◽  
T. J. Ebner

1. The spatial patterns of activation in the rat cerebellar cortex evoked by peripheral stimulation were studied in vivo using optical imaging techniques. 2. Crus I and Crus II were stained with the pH sensitive dye, neutral red. Electrical stimulation of the vibrissae area of the ipsilateral face evoked optical responses consisting of parasagittal bands. The bands were 100–300 microns in width, elongated in the anterior-posterior direction, commonly extended across at least two folia, and varied in number from 1 to 7. 3. The optical responses were dependent on activation of postsynaptic elements since they were decreased substantially by the non-N-methyl-D-aspartate antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione. The optical bands were shown to correspond anatomically with the parasagittal compartments revealed by immunostaining with anti-zebrin II. 4. The present study demonstrates that functional parasagittal compartments exist in the rat cerebellar cortex and suggests that zebrin-positive Purkinje cell subgroups are anatomically related to this functional organization.

1999 ◽  
Vol 81 (4) ◽  
pp. 1992-1998 ◽  
Author(s):  
G. Chen ◽  
C. L. Hanson ◽  
R. L. Dunbar ◽  
T. J. Ebner

Novel form of spreading acidification and depression in the cerebellar cortex demonstrated by neutral red optical imaging. A novel form of spreading acidification and depression in the rat cerebellar cortex was imaged in vivo using the pH-sensitive dye, Neutral red. Surface stimulation evoked an initial beam of increased fluorescence (i.e., decreased pH) that spread rostrally and caudally across the folium and into neighboring folia. A transient but marked suppression in the excitability of the parallel fiber-Purkinje cell circuitry accompanied the spread. Characteristics differentiating this phenomenon from the spreading depression of Leao include: high speed of propagation on the surface (average of 450 μm/s), stable extracellular DC potential, no change in blood vessel diameter, and repeatability at short intervals. This propagating acidification constitutes a previously unknown class of neuronal processing in the cerebellar cortex.


2007 ◽  
Vol 97 (1) ◽  
pp. 248-263 ◽  
Author(s):  
Fidel Santamaria ◽  
Patrick G. Tripp ◽  
James M. Bower

Synapses associated with the parallel fiber (pf) axons of cerebellar granule cells constitute the largest excitatory input onto Purkinje cells (PCs). Although most theories of cerebellar function assume these synapses produce an excitatory sequential “beamlike” activation of PCs, numerous physiological studies have failed to find such beams. Using a computer model of the cerebellar cortex we predicted that the lack of PCs beams is explained by the concomitant pf activation of feedforward molecular layer inhibition. This prediction was tested, in vivo, by recording PCs sharing a common set of pfs before and after pharmacologically blocking inhibitory inputs. As predicted by the model, pf-induced beams of excitatory PC responses were seen only when inhibition was blocked. Blocking inhibition did not have a significant effect in the excitability of the cerebellar cortex. We conclude that pfs work in concert with feedforward cortical inhibition to regulate the excitability of the PC dendrite without directly influencing PC spiking output. This conclusion requires a significant reassessment of classical interpretations of the functional organization of the cerebellar cortex.


2019 ◽  
Vol 20 (8) ◽  
pp. 2052 ◽  
Author(s):  
El Cheikh Hussein ◽  
Mollard ◽  
Bonnefont

Why do we experience the ailments of jetlag when we travel across time zones? Why is working night-shifts so detrimental to our health? In other words, why can’t we readily choose and stick to non-24 h rhythms? Actually, our daily behavior and physiology do not simply result from the passive reaction of our organism to the external cycle of days and nights. Instead, an internal clock drives the variations in our bodily functions with a period close to 24 h, which is supposed to enhance fitness to regular and predictable changes of our natural environment. This so-called circadian clock relies on a molecular mechanism that generates rhythmicity in virtually all of our cells. However, the robustness of the circadian clock and its resilience to phase shifts emerge from the interaction between cell-autonomous oscillators within the suprachiasmatic nuclei (SCN) of the hypothalamus. Thus, managing jetlag and other circadian disorders will undoubtedly require extensive knowledge of the functional organization of SCN cell networks. Here, we review the molecular and cellular principles of circadian timekeeping, and their integration in the multi-cellular complexity of the SCN. We propose that new, in vivo imaging techniques now enable to address these questions directly in freely moving animals.


Neuroscience ◽  
1998 ◽  
Vol 84 (3) ◽  
pp. 645-668 ◽  
Author(s):  
G Chen ◽  
C.L Hanson ◽  
T.J Ebner

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Matthew L. Scarpelli ◽  
Debbie R. Healey ◽  
Shwetal Mehta ◽  
Vikram D. Kodibagkar ◽  
Christopher C. Quarles

Abstract Many neurological diseases present with substantial genetic and phenotypic heterogeneity, making assessment of these diseases challenging. This has led to ineffective treatments, significant morbidity, and high mortality rates for patients with neurological diseases, including brain cancers and neurodegenerative disorders. Improved understanding of this heterogeneity is necessary if more effective treatments are to be developed. We describe a new method to measure phenotypic heterogeneity across the whole rodent brain at multiple spatial scales. The method involves co-registration and localized comparison of in vivo radiologic images (e.g. MRI, PET) with ex vivo optical reporter images (e.g. labeled cells, molecular targets, microvasculature) of optically cleared tissue slices. Ex vivo fluorescent images of optically cleared pathology slices are acquired with a preclinical in vivo optical imaging system across the entire rodent brain in under five minutes, making this methodology practical and feasible for most preclinical imaging labs. The methodology is applied in various examples demonstrating how it might be used to cross-validate and compare in vivo radiologic imaging with ex vivo optical imaging techniques for assessing hypoxia, microvasculature, and tumor growth.


2018 ◽  
Vol 143 (3) ◽  
pp. 288-298 ◽  
Author(s):  
Wendy A. Wells ◽  
Michael Thrall ◽  
Anastasia Sorokina ◽  
Jeffrey Fine ◽  
Savitri Krishnamurthy ◽  
...  

The traditional surgical pathology assessment requires tissue to be removed from the patient, then processed, sectioned, stained, and interpreted by a pathologist using a light microscope. Today, an array of alternate optical imaging technologies allow tissue to be viewed at high resolution, in real time, without the need for processing, fixation, freezing, or staining. Optical imaging can be done in living patients without tissue removal, termed in vivo microscopy, or also in freshly excised tissue, termed ex vivo microscopy. Both in vivo and ex vivo microscopy have tremendous potential for clinical impact in a wide variety of applications. However, in order for these technologies to enter mainstream clinical care, an expert will be required to assess and interpret the imaging data. The optical images generated from these imaging techniques are often similar to the light microscopic images that pathologists already have expertise in interpreting. Other clinical specialists do not have this same expertise in microscopy, therefore, pathologists are a logical choice to step into the developing role of microscopic imaging expert. Here, we review the emerging technologies of in vivo and ex vivo microscopy in terms of the technical aspects and potential clinical applications. We also discuss why pathologists are essential to the successful clinical adoption of such technologies and the educational resources available to help them step into this emerging role.


1997 ◽  
Vol 77 (4) ◽  
pp. 2191-2196 ◽  
Author(s):  
Geoffrey M. Ghose ◽  
Daniel Y. Ts'O

Ghose, Geoffrey M. and Daniel Y. Ts'o. Form processing modules in primate area V4. J. Neurophysiol. 77: 2191–2196, 1997. Area V4 occupies a central position among the areas of the primate cerebral cortex involved with object recognition and analysis. Consistent with this role, neurons in V4 are selective for many visual attributes including color, orientation, and binocular disparity. However, it is uncertain whether cells within V4 are organized with respect to these properties. In this study we used in vivo optical imaging and electrophysiology in macaque visual cortex to show that cells that share certain physiological properties are indeed grouped together in V4. Our results revealed regions containing cells with common orientation selectivity. These regions were similar in size to those seen in V2 and much larger than those seen in V1 and were confirmed by appropriately targeted single-unit recording. Surprisingly, orientation organization visible through imaging was limited to the portion of V4 representing the central visual fields. Optical imaging also revealed a functional organization related to stimulus size. Size-sensitive regions (S regions) contained cells that were strongly suppressed by large stimuli. In contrast to V2, S regions in V4 contain orientation domains. These results suggest that V4 contains modular assemblies of cells related to particular aspects of form analysis. Such organization may contribute to the construction of object-based representations.


Nature ◽  
1969 ◽  
Vol 222 (5195) ◽  
pp. 771-772 ◽  
Author(s):  
RICHARD G. BUCKLES ◽  
CAMERON KNOX

2011 ◽  
Vol 105 (4) ◽  
pp. 1732-1746 ◽  
Author(s):  
Xinming Wang ◽  
Gang Chen ◽  
Wangcai Gao ◽  
Timothy J. Ebner

The parallel fibers (PFs) in the cerebellar cortex extend several millimeters along a folium in the mediolateral direction. The PFs are orthogonal to and cross several parasagittal zones defined by the olivocerebellar and corticonuclear pathways and the expression of molecular markers on Purkinje cells (PCs). The functions of these two organizations remain unclear, including whether the bands respond similarly or differentially to PF input. By using flavoprotein imaging in the anesthetized mouse in vivo, this study demonstrates that high-frequency PF stimulation, which activates a beamlike response at short latency, also evokes patches of activation at long latencies. These patches consist of increased fluorescence along the beam at latencies of 20–25 s with peak activation at 35 s. The long-latency patches are completely blocked by the type 1 metabotropic glutamate receptor (mGluR1) antagonist LY367385. Conversely, the AMPA and NMDA glutamate receptor antagonists DNQX and APV have little effect. Organized in parasagittal bands, the long-latency patches align with zebrin II-positive PC stripes. Additional Ca2+ imaging demonstrates that the patches reflect increases in intracellular Ca2+. Both the PLCβ inhibitor U73122 and the ryanodine receptor inhibitor ryanodine completely block the long-latency patches, indicating that the patches are due to Ca2+ release from intracellular stores. Robust, mGluR1-dependent long-term potentiation (LTP) of the patches is induced using a high-frequency PF stimulation conditioning paradigm that generates LTP of PF-PC synapses. Therefore, the parasagittal bands, as defined by the molecular compartmentalization of PCs, respond differentially to PF inputs via mGluR1-mediated release of internal Ca2+.


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