Golgi cells, granule cells and synaptic glomeruli in the molecular layer of the rabbit cerebellar cortex

1973 ◽  
Vol 2 (4) ◽  
pp. 407-428 ◽  
Author(s):  
J. Spačer ◽  
J. Pařízek ◽  
A. R. Lieberman
Keyword(s):  
Cerebellar Cortex ◽  
Granule Cells ◽  
Molecular Layer ◽  
Golgi Cells

Feedforward Inhibition Controls the Spread of Granule Cell–Induced Purkinje Cell Activity in the Cerebellar Cortex

2007 ◽  
Vol 97 (1) ◽  
pp. 248-263 ◽  
Author(s):  
Fidel Santamaria ◽  
Patrick G. Tripp ◽  
James M. Bower
Keyword(s):  
Cerebellar Cortex ◽  
Granule Cells ◽  
Functional Organization ◽  
Cerebellar Granule Cells ◽  
Molecular Layer ◽  
Cell Activity ◽  
Excitatory Input ◽  
Cortical Inhibition ◽  
Before And After

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.

Cerebellar Granule Cells and Their Response to Radiation

1970 ◽  
Vol 28 ◽  
pp. 212-213
Author(s):  
Rosita F. de Estable-Puig ◽  
Juan F. Estable-Puig
Keyword(s):  
Cerebellar Cortex ◽  
Granular Layer ◽  
Granule Cells ◽  
Cerebellar Granule Cells ◽  
Mossy Fiber ◽  
Molecular Layer ◽  
Synaptic Connections ◽  
Cerebellar Granule ◽  
Peripheral Axon ◽  
Cerebellar Glomerulus

The granular layer of the cerebellar cortex situated between the molecular and medullary layers is built up mainly of the perikarya of small interneurons, the granule cells intermingled with part of their own processes, mossy fiber terminals, fibers of passage and other less numerous intrinsic cells. Ultrastructurally they are characterized by a nucleus which occupies most of the cell body and a rim of cytoplasm. The nucleus exhibits some aggregates of chromatin and in some cells a nucleolus. In the cytoplasm very scarce organelles are observed (Fig.l). Their main synaptic connections are found, first, at the cerebellar glomerulus where granule dendrites are seen in postsynaptic position towards mossy fiber rosettes. Desmosomic attachments are observed between granule dendrites. Second, at the level of the molecular layer where parallel fiber terminals (ramifications of the peripheral axon ) are seen apposing Purkinje dendrite spines.

Focal synaptic potentials due to discrete mossy-fibre arrival volleys in the cerebellar cortex

1987 ◽  
Vol 231 (1263) ◽  
pp. 217-230 ◽  
Keyword(s):  
Cerebellar Cortex ◽  
Granule Cells ◽  
Molecular Layer ◽  
Field Potential ◽  
Mossy Fibre ◽  
Synaptic Potential ◽  
Presynaptic Spike ◽  
Cell Firing ◽  
Mossy Fibres ◽  
Afferent Volleys

The previously described direct and relayed projections of periodontal afferents to the cerebellar cortex have been examined in detail by extracellular field-potential analysis. Advantage is taken of the very small temporal dispersion of the afferent volleys to permit identification of the presynaptic spike potential of mossy fibres, the subsequent synaptic potential and the firing of granule cells. Changes in form of the presynaptic potential with depth are compared with published descriptions of presynaptic potentials elsewhere. The negative synaptic potential in the granular layer is shown to have a positive aspect in the molecular layer. Granule-cell firing can, under some conditions, yield a population spike interrupting the synaptic potential wave. Records are presented showing all-or-none complex waves, which appear to be single glomerular potentials not previously described in the mammalian cerebellum. Their distinction from cellular spike potentials is emphasized.

scholarly journals Integrative Versus Delay Line Characteristics of Cerebellar Cortex

1976 ◽  
Vol 3 (2) ◽  
pp. 85-97 ◽  
Author(s):  
W.A. MacKay ◽  
J.T. Murphy
Keyword(s):  
Cerebellar Cortex ◽  
Cell Activation ◽  
Delay Line ◽  
Granule Cells ◽  
Molecular Layer ◽  
Parallel Fiber ◽  
Response Latencies ◽  
Integrator Model ◽  
P Cells

SUMMARY:In order to determine which of two general models (“tapped delay line” or “integrator”) provides a more accurate description of mammalian Purkinje cell (P-cell) activation by natural stimulation, the spatial and temporal characteristics of a population of neurons in cerebellar cortex responsive to small controlled stretches of forelimb muscles were examined in awake, locally anesthetized cats. Stretch of a single wrist muscle excited P-cells over a distance of about 1 mm in the long axis of a folium, a span which is at most half the length of parallel fibers. Both granule cells and molecular layer interneurons were excited over a wider zone than P-cells.Furthermore, P-cells across a response zone all fired on the average at the same time, as determined by computing peristimulus cross-interval histograms from pairs of simultaneously recorded neurons. Consistent delays could only be demonstrated in the minimal response latencies as measured from peristimulus time histograms. These delays, however, were longer than could be ascribed to parallel fiber conduction velocity.No evidence, therefore, was found in cat cerebellum to support the “tapped delay line” model, which postulates the successive activation of P-cells as an excitatory volley travels along a parallel fiber beam. Instead, an integrative mode of operation seems to predominate: a relatively wide substratum of activated granule cells simultaneously activates a narrower focus of P-cells centrally situated with respect to the granule cell population. The role of inhibitory interneurons in promoting the “integrator” model is discussed.

Cerebellar On-Beam and Lateral Inhibition: Two Functionally Distinct Circuits

2000 ◽  
Vol 83 (4) ◽  
pp. 1932-1940 ◽  
Author(s):  
Dana Cohen ◽  
Yosef Yarom
Keyword(s):  
Cerebellar Cortex ◽  
Stimulus Intensity ◽  
Lateral Inhibition ◽  
Time Course ◽  
Granule Cells ◽  
Functional Organization ◽  
Mossy Fiber ◽  
Molecular Layer ◽  
Cell Inhibition ◽  
Voltage Sensitive Dyes

Optical imaging of voltage-sensitive dyes in an isolated cerebellum preparation was used to study the spatiotemporal functional organization of the inhibitory systems in the cerebellar cortex. Responses to surface stimulation of the cortex reveal two physiologically distinct inhibitory systems, which we refer to as lateral and on-beam inhibition following classical terminology. Lateral inhibition occurs throughout the area responding to a stimulus, whereas on-beam inhibition is confined to the area directly excited by parallel fibers. The time course of the lateral inhibition is twice as long as that of the on-beam inhibition. Both inhibitory responses increase with stimulus intensity, but the lateral inhibition has a lower threshold, and it saturates at lower stimulus intensity. The amplitude of the on-beam inhibition is linearly related to the excitation at the same location, whereas that of the lateral inhibition is linearly related to the excitation at the center of the beam. Repetitive stimulation is required to activate on-beam inhibition, whereas the same stimulus paradigm reveals prolonged depression of the lateral inhibition. We conclude that lateral inhibition reflects the activation of molecular layer interneurons, and its major role is to increase the excitability of the activated area by disinhibition. The on-beam inhibition most likely reflects Golgi cell inhibition of granule cells. However, Purkinje cell collateral inhibition of Golgi cells cannot be excluded. Both possibilities suggest that the role of the on-beam inhibition is to efficiently modulate, in time and space, the mossy fiber input to the cerebellar cortex.

scholarly journals Deposition and role of thrombospondin in the histogenesis of the cerebellar cortex.

1990 ◽  
Vol 110 (4) ◽  
pp. 1275-1283 ◽  
Author(s):  
K S O'Shea ◽  
J S Rheinheimer ◽  
V M Dixit
Keyword(s):  
Cell Migration ◽  
Cerebellar Cortex ◽  
Granule Cell ◽  
Granule Cells ◽  
Cell Layer ◽  
Molecular Layer ◽  
Granule Cell Layer ◽  
External Granule Cell Layer ◽  
Dependent Inhibition ◽  
Cell Layers

The patterns of deposition of thrombospondin (TSP), a trimeric extracellular matrix glycoprotein, were determined during the initial establishment of the external granule cell layer and the subsequent inward migration of granule cells forming the molecular and (internal) granule cell layers. The early homogeneous deposition of TSP became restricted to the rhombic lip in the region of granule cell exit from the neuroepithelium, and was present between migrating granule cells. During the later inward migration of granule cells, little TSP was associated with dividing granule cells; it was enriched in premigratory granule cells. With the cessation of migration, TSP was lost except in association with fasciculating axons in the molecular layer where staining persisted briefly. At the EM level, TSP was associated with the leading process of granule cells as they associated with Bergmann glial cells and migrated through the molecular layer. TSP was present within granule cell axons; Purkinje cells and their dendrites, as well as Bergmann glial fibers and endfeet were negative for TSP. When anti-TSP antibodies were added to explant cultures of cerebellar cortex during active granule cell migration, a dose-dependent inhibition of migration was observed. In control cultures, granule cells migrated into the (internal) granule cell layer, while granule cells exposed to anti-TSP antibodies were arrested within the external granule cell layer. These results suggest that TSP plays an important role in the histogenesis of the cerebellar cortex by influencing granule cell migration.

scholarly journals A novel inhibitory nucleo-cortical circuit controls cerebellar Golgi cell activity

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Lea Ankri ◽  
Zoé Husson ◽  
Katarzyna Pietrajtis ◽  
Rémi Proville ◽  
Clément Léna ◽  
...  
Keyword(s):  
Cerebellar Cortex ◽  
Motor Coordination ◽  
Granule Cells ◽  
Cell Activity ◽  
Cerebellar Nuclei ◽  
Golgi Cell ◽  
Main Mode ◽  
Golgi Cells

The cerebellum, a crucial center for motor coordination, is composed of a cortex and several nuclei. The main mode of interaction between these two parts is considered to be formed by the inhibitory control of the nuclei by cortical Purkinje neurons. We now amend this view by showing that inhibitory GABA-glycinergic neurons of the cerebellar nuclei (CN) project profusely into the cerebellar cortex, where they make synaptic contacts on a GABAergic subpopulation of cerebellar Golgi cells. These spontaneously firing Golgi cells are inhibited by optogenetic activation of the inhibitory nucleo-cortical fibers both in vitro and in vivo. Our data suggest that the CN may contribute to the functional recruitment of the cerebellar cortex by decreasing Golgi cell inhibition onto granule cells.

scholarly journals Candelabrum cells are molecularly distinct, ubiquitous interneurons of the cerebellar cortex with specialized circuit properties

2021 ◽  
Author(s):  
Tomas Osorno ◽  
Stephanie Rudolph ◽  
Tri Nguyen ◽  
Velina Kozareva ◽  
Naeem Nadaf ◽  
...  
Keyword(s):  
Cerebellar Cortex ◽  
Granule Cells ◽  
Mossy Fiber ◽  
Molecular Layer ◽  
Unique Role ◽  
Electrophysiological Properties ◽  
Highly Sensitive ◽  
And Function ◽  
Serial Electron Microscopy

AbstractTo understand how the cerebellar cortex transforms mossy fiber (MF) inputs into Purkinje cell (PC) outputs, it is vital to delineate the elements of this circuit. Candelabrum cells (CCs) are enigmatic interneurons of the cerebellar cortex that have been identified based on their morphology, but their electrophysiological properties, synaptic connections, and function remain unknown. Here we clarify these properties using electrophysiology, snRNA sequencing, in situ hybridization, and serial electron microscopy. We find that CCs are the most abundant PC layer interneuron. They are GABAergic, molecularly distinct, and present in all cerebellar lobules. Their high resistance renders CC firing highly sensitive to synaptic inputs. CCs are excited by MFs and granule cells, and strongly inhibited by PCs. CCs in turn inhibit molecular layer interneurons, which leads to PC disinhibition. Thus, inputs, outputs and local signals all converge onto CCs to allow them to assume a unique role in controlling cerebellar output.

Sign in / Sign up

Export Citation Format

Share Document