Long-lasting depression of parallel fiber-Purkinje cell transmission induced by conjunctive stimulation of parallel fibers and climbing fibers in the cerebellar cortex

1982 ◽  
Vol 33 (3) ◽  
pp. 253-258 ◽  
Author(s):  
Masao Ito ◽  
Masanobu Kano
Keyword(s):  
Purkinje Cell ◽  
Cerebellar Cortex ◽  
Parallel Fiber ◽  
Climbing Fibers ◽  
Parallel Fibers ◽  
Cell Transmission ◽  
Stimulation Of

Laminar analysis of activity-dependent increases of CBF in rat cerebellar cortex: dependence on synaptic strength

1997 ◽  
Vol 273 (3) ◽  
pp. H1166-H1176 ◽  
Author(s):  
N. Akgoren ◽  
C. Mathiesen ◽  
I. Rubin ◽  
M. Lauritzen
Keyword(s):  
Electrical Stimulation ◽  
Purkinje Cells ◽  
Cerebellar Cortex ◽  
Synaptic Strength ◽  
Parallel Fiber ◽  
Climbing Fibers ◽  
Parallel Fibers ◽  
Doppler Flowmetry ◽  
Activity Dependent ◽  
Stimulation Of

The purpose of the present study was to examine mechanisms of activity-dependent changes of cerebral blood flow (CBF) in rat cerebellar cortex by laser-Doppler flowmetry, using two synaptic inputs that excite different regions of the same target cell and with different synaptic strength. The apical part of Purkinje cells was activated by electrical stimulation of parallel fibers, whereas the cell soma and the proximal part of the dendritic tree were activated by climbing fibers using harmaline (40 mg/kg ip) or electrical stimulation of the inferior olive. Glass microelectrodes were used for recordings of field potentials and single-unit activity of Purkinje cells. CBF increases evoked by parallel fibers were most pronounced in the upper cortical layers. In contrast, climbing fiber stimulation increased CBF in the entire cortex. Inhibition of nitric oxide (NO) synthase activity by NG-nitro-L-arginine (L-NNA) or guanylate cyclase activity by 1H-[1,2,4(oxadiazolo)4,3-a]quinoxaline-1-one did not affect basal or harmaline-induced Purkinje cell activity but attenuated harmaline- and parallel fiber-evoked CBF increases by approximately 40-50%. Application of 8-(p-sulfophenyl)theophylline and adenosine deaminase reduced the harmaline-evoked CBF increase without any effect on the parallel fiber-evoked CBF response. The results suggest that CBF increases elicited by activation of Purkinje cells are partially mediated by the NO-guanosine 3',5'-cyclic monophosphate system independent of the input function but that adenosine contributes as well when climbing fibers are activated. This is the first demonstration of variations of coupling as a function of postsynaptic activity in the same cell.

Congruence of spatial organization of tactile projections to granule cell and Purkinje cell layers of cerebellar hemispheres of the albino rat: vertical organization of cerebellar cortex

1983 ◽  
Vol 49 (3) ◽  
pp. 745-766 ◽  
Author(s):  
J. M. Bower ◽  
D. C. Woolston
Keyword(s):  
Purkinje Cell ◽  
Cerebellar Cortex ◽  
Body Surface ◽  
Granule Cell ◽  
Spike Activity ◽  
Body Part ◽  
Parallel Fibers ◽  
Simple Spike ◽  
Vertical Organization ◽  
Stimulation Of

1. We compared the spatial pattern of shortest latency somatosensory (tactile) projections to the Purkinje cell (PC) layer and to the underlying granule cell (GC) layer in tactile areas of rat cerebellar cortex. Micro-mapping methods were used to sample single units in the PC layer and multiple units in the GC layer of both anesthetized and unanesthetized rats. Mechanical and electrical stimulation of the body surface were employed. Responsiveness of PCs to cutaneous stimulation was assessed by constructing histograms of simple spike activity and statistically comparing poststimulus activity to nonstimulated base-line PC activity. 2. We found that PCs respond to tactile stimulation with increases (7-10 ms) followed by decreases (8-15 ms) in simple spike activity. Increases in simple spike activity followed activation of the underlying GC layer by 1-4 ms, while decreases in simple spike activity were found 2-5 ms after GC layer activation. 3. PCs were found to have both excitatory and inhibitory receptive fields (RFs). Excitatory RFs were restricted to small areas of a single body part and for each PC were very similar or identical to the RFs of neurons in the immediately subjacent GC layer. Inhibitory PC RFs were larger, often containing more than one body part and for each PC, were only partially similar to the RFs of subjacent GCs. PC inhibitory RFs also often included body surfaces projecting to the nearby but not to the underlying GC layer. 4. Stimulation of a single peripheral locus resulted in small, distinct regions of PC layer excitation and inhibition. Areas of PC excitation overlie activated regions of the GC layer, while inhibited PCs overlie both activated and nonactivated GC regions. 5. We found PCs to be organized in groups or patches with respect to the specific body region that was capable of activating them (upper lip, lower lip, etc.). Adjacent patches of PCs often represented widely separated body parts. This pattern of PC layer activating RF projections was congruent with the pattern of excitatory RF projections to the underlying GC layer. 6. These results indicate that there is a vertical organization in GC-PC excitatory relations, while GC-induced PC inhibition is slightly more widely distributed. 7. Our finding that the patchlike activation of PCs is congruent with that of the underlying GC layer contrasts with the classical concept that PCs are activated by parallel fibers in a "beamlike" fashion from a patch of GCs. Thus, a reevaluation of the role of parallel fibers seems to us to be in order. 8. In conclusion, our results support the view that short-latency afferent tactile projections to both the GC and PC layers of cerebellar cortex are highly organized spatially. This specificity of body surface projections must be incorporated into modern views of the functional organization of cerebellar cortex.

Responses to parallel fiber stimulation in the guinea pig dorsal cochlear nucleus in vitro

1989 ◽  
Vol 61 (1) ◽  
pp. 149-161 ◽  
Author(s):  
P. B. Manis
Keyword(s):  
Field Potential ◽  
Dorsal Cochlear Nucleus ◽  
Parallel Fiber ◽  
Field Potentials ◽  
Pial Surface ◽  
Negative Wave ◽  
Parallel Fibers ◽  
Layer 2 ◽  
Fiber Stimulation ◽  
Stimulation Of

1. Parallel fibers of the guinea pig dorsal cochlear nucleus (DCN) were electrically stimulated at the pial surface of the nucleus in a brain-slice preparation. Extracellular field potentials produced by the parallel fibers and postsynaptic cells, and the response of single units were identified and characterized. Responses were compared with those reported for stimulation of parallel fibers in the cerebellum and to those seen with electrical stimulation of the auditory nerve. 2. Stimulation of the DCN parallel fibers generates a consistent set of extracellular field potentials. In layer 1 of the DCN, a short-latency triphasic wave (P1(1)-N1(1)-P2(1)) is followed by a slower negative wave (N2(1)). The onset phase of the N2(1) often exhibits a small positive notch (P2a1). In layer 2, an initial triphasic wave (P1(2)-N1(2)-P2(2)) is followed by a short-latency negative wave (N2(2)) and a slower positive wave (P3(2)). The N1(2) is approximately coincident with the N1(1), whereas the P3(2) is coincident with N2(1). The falling phase of the P3(2) is sometimes interrupted by a brief negative deflection (N3(2)). These field potentials are similar, but not identical to those reported for parallel fiber stimulation in the cerebellum in vivo (15). These responses differ substantially from those produced in the DCN by electrical stimulation of the auditory nerve (50). 3. Low-calcium solutions and pharmacologic manipulations were used to separate pre- and postsynaptic response components in the field potential records. When the slice is bathed in a low-calcium solution the P2a1, N2(1), N2(2), P3(2), and the brief late deflections are abolished. However, the P1(1)-N1(1)-P2(1) and P1(2)-N1(2)-P2(2) remain unaffected. A similar separation of pre- and postsynaptic components can be achieved with 100 microM adenosine or 0.5 mM kynurenic acid. It is concluded that the P1(1)-M1(1)-P2(1) wave is the compound action potential of the unmyelinated parallel fibers, whereas the longer-latency field potential components are generated postsynaptically. 4. The conduction velocity of the parallel fiber volley was measured to be 0.30 m/s at the pial surface, in a line approximately parallel to the strial axis of the nucleus. Mapping experiments reveal that the spread of the P1(1)-N1(1)-P2(1) is greatest along the strial axis, and more limited in the orthogonal direction. 5. Single units were recorded in layer 2. At a distance of 500-700 microns from the stimulating electrode, the latencies of single-unit discharges fall between 2.5 and 4 ms, at the time of the N2(2).(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Local Estrogen Synthesis Regulates Parallel Fiber–Purkinje Cell Neurotransmission Within the Cerebellar Cortex

Endocrinology ◽  
2018 ◽  
Vol 159 (3) ◽  
pp. 1328-1338 ◽  
Author(s):  
Valerie L Hedges ◽  
Gang Chen ◽  
Lei Yu ◽  
Amanda A Krentzel ◽  
Joseph R Starrett ◽  
...  
Keyword(s):  
Purkinje Cell ◽  
Cerebellar Cortex ◽  
Metabotropic Glutamate Receptor ◽  
Receptor Activation ◽  
Parallel Fiber ◽  
Aromatase Activity ◽  
Glutamatergic Neurotransmission ◽  
Metabotropic Glutamate ◽  
Estrogen Synthesis ◽  
Glutamatergic Signaling

Abstract Estrogens affect cerebellar activity and cerebellum-based behaviors. Within the adult rodent cerebellum, the best-characterized action of estradiol is to enhance glutamatergic signaling. However, the mechanisms by which estradiol promotes glutamatergic neurotransmission remain unknown. Within the mouse cerebellum, we found that estrogen receptor activation of metabotropic glutamate receptor type 1a strongly enhances neurotransmission at the parallel fiber–Purkinje cell synapse. The blockade of local estrogen synthesis within the cerebellum results in a diminution of glutamatergic neurotransmission. Correspondingly, decreased estrogen availability via gonadectomy or blockade of aromatase activity negatively affects locomotor performance. These data indicate that locally derived, and not just gonad-derived, estrogens affect cerebellar physiology and function. In addition, estrogens were found to facilitate parallel fiber–Purkinje cell synaptic transmission in both sexes. As such, the actions of estradiol to support cerebellar neurotransmission and cerebellum-based behaviors might be fundamental to understanding the normal processing of activity within the cerebellar cortex.

scholarly journals The Theories of Gerbrandus Jelgersma (1859–1942) on the Function of the Cerebellum

2021 ◽  
Author(s):  
Jan Voogd
Keyword(s):  
Purkinje Cell ◽  
Purkinje Cells ◽  
Mossy Fiber ◽  
Parallel Fiber ◽  
Climbing Fibers ◽  
Late Nineteenth Century ◽  
Superior Cerebellar Peduncle ◽  
Fiber System ◽  
Coordination System ◽  
Cerebellar Peduncle

AbstractGerbrandus Jelgersma published extensively on the (pathological) anatomy of the cerebellum between 1886 and 1934. Based on his observations on the double innervation of the Purkinje cells, he formulated a hypothesis on the function of the cerebellum. Both afferent systems of the cerebellum, the mossy fiber-parallel fiber system and the climbing fibers terminate on the Purkinje cell dendrites. According to Jelgersma, the mossy fiber-parallel fiber system is derived from the pontine nuclei and the inferior olive, and would transmit the movement images derived from the cerebral cortex. Spinocerebellar climbing fibers would transmit information about the execution of the movement. When the Purkinje cell compares these inputs and notices a difference between instruction and execution, it sends a correction through the descending limb of the superior cerebellar peduncle to the anterior horn cells. Jelgersma postulates that this cerebro-cerebellar coordination system shares plasticity with other nervous connections because nerve cell dendritic protrusions possess what he called amoeboid mobility: dendritic protrusions can be extended or retracted and are so able to create new connections or to abolish them. Jelgersma’s theories are discussed against the background of more recent theories of cerebellar function that, similarly, are based on the double innervation of the Purkinje cells. The amoeboid hypothesis is traced to its roots in the late nineteenth century.

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