scholarly journals Modulated discharge of Purkinje and stellate cells persists after unilateral loss of vestibular primary afferent mossy fibers in mice

2013 ◽  
Vol 110 (10) ◽  
pp. 2257-2274 ◽  
Author(s):  
N. H. Barmack ◽  
V. Yakhnitsa
Keyword(s):  
Purkinje Cells ◽  
Stellate Cell ◽  
Mossy Fibers ◽  
Stellate Cells ◽  
Climbing Fibers ◽  
Afferent Pathways ◽  
Parallel Fibers ◽  
Primary Afferent ◽  
Low Frequencies ◽  
Cell Discharge

Cerebellar Purkinje cells are excited by two afferent pathways: climbing and mossy fibers. Climbing fibers evoke large “complex spikes” (CSs) that discharge at low frequencies. Mossy fibers synapse on granule cells whose parallel fibers excite Purkinje cells and may contribute to the genesis of “simple spikes” (SSs). Both afferent systems convey vestibular information to folia 9c–10. After making a unilateral labyrinthectomy (UL) in mice, we tested how the discharge of CSs and SSs was changed by the loss of primary vestibular afferent mossy fibers during sinusoidal roll tilt. We recorded from cells identified by juxtacellular neurobiotin labeling. The UL preferentially reduced vestibular modulation of CSs and SSs in folia 8–10 contralateral to the UL. The effects of a UL on Purkinje cell discharge were similar in folia 9c–10, to which vestibular primary afferents project, and in folia 8–9a, to which they do not project, suggesting that vestibular primary afferent mossy fibers were not responsible for the UL-induced alteration of SS discharge. UL also induced reduced vestibular modulation of stellate cell discharge contralateral to the UL. We attribute the decreased modulation to reduced vestibular modulation of climbing fibers. In summary, climbing fibers modulate CSs directly and SSs indirectly through activation of stellate cells. Whereas vestibular primary afferent mossy fibers cannot account for the modulated discharge of SSs or stellate cells, the nonspecific excitation of Purkinje cells by parallel fibers may set an operating point about which the discharges of SSs are sculpted by climbing fibers.

scholarly journals Adaptive Balance in Posterior Cerebellum

2021 ◽  
Vol 12 ◽  
Author(s):  
Neal H. Barmack ◽  
Vito Enrico Pettorossi
Keyword(s):  
Purkinje Cells ◽  
Stellate Cell ◽  
Semicircular Canals ◽  
Mossy Fibers ◽  
Vestibular Nuclei ◽  
Three Dimensions ◽  
Optokinetic Stimulation ◽  
Afferent Pathways ◽  
Vestibular Nuclear Neurons ◽  
Self Motion

Vestibular and optokinetic space is represented in three-dimensions in vermal lobules IX-X (uvula, nodulus) and hemisphere lobule X (flocculus) of the cerebellum. Vermal lobules IX-X encodes gravity and head movement using the utricular otolith and the two vertical semicircular canals. Hemispheric lobule X encodes self-motion using optokinetic feedback about the three axes of the semicircular canals. Vestibular and visual adaptation of this circuitry is needed to maintain balance during perturbations of self-induced motion. Vestibular and optokinetic (self-motion detection) stimulation is encoded by cerebellar climbing and mossy fibers. These two afferent pathways excite the discharge of Purkinje cells directly. Climbing fibers preferentially decrease the discharge of Purkinje cells by exciting stellate cell inhibitory interneurons. We describe instances adaptive balance at a behavioral level in which prolonged vestibular or optokinetic stimulation evokes reflexive eye movements that persist when the stimulation that initially evoked them stops. Adaptation to prolonged optokinetic stimulation also can be detected at cellular and subcellular levels. The transcription and expression of a neuropeptide, corticotropin releasing factor (CRF), is influenced by optokinetically-evoked olivary discharge and may contribute to optokinetic adaptation. The transcription and expression of microRNAs in floccular Purkinje cells evoked by long-term optokinetic stimulation may provide one of the subcellular mechanisms by which the membrane insertion of the GABAA receptors is regulated. The neurosteroids, estradiol (E2) and dihydrotestosterone (DHT), influence adaptation of vestibular nuclear neurons to electrically-induced potentiation and depression. In each section of this review, we discuss how adaptive changes in the vestibular and optokinetic subsystems of lobule X, inferior olivary nuclei and vestibular nuclei may contribute to the control of balance.

Distal Versus Proximal Inhibitory Shaping of Feedback Excitation in the Electrosensory Lateral Line Lobe: Implications for Sensory Filtering

1998 ◽  
Vol 80 (6) ◽  
pp. 3214-3232 ◽  
Author(s):  
Neil J. Berman ◽  
Leonard Maler
Keyword(s):  
Lateral Line ◽  
Pyramidal Cell ◽  
Stellate Cell ◽  
Molecular Layer ◽  
Pyramidal Cells ◽  
Stellate Cells ◽  
Decay Phase ◽  
Tetanic Stimulation ◽  
Parallel Fibers ◽  
Cell Inhibition

Berman, Neil J. and Leonard Maler. Distal versus proximal inhibitory shaping of feedback excitation in the electrosensory lateral line lobe: implications for sensory filtering. J. Neurophysiol. 80: 3214–3232, 1998. The inhibition controlling the indirect descending feedback (parallel fibers originating from cerebellar granule cells in the eminentia posterior pars granularis) to electrosensory lateral line lobe (ELL) pyramidal cells was studied using intracellular recording techniques in vitro. Parallel fibers (PF) contact stellate cells and dendrites of ventral molecular layer (VML) GABAergic interneurons. Stellate cells provide local input to pyramidal cell distal dendrites, whereas VML cells contact their somata and proximal dendrites. Single-pulse stimulation of PF evoked graded excitatory postsynaptic potentials (EPSPs) that were blocked by α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid and N-methyl-d-aspartate (NMDA) antagonists. The EPSPs peaked at 6.4 ± 1.8 ms (mean ± SE; n = 11) but took >50 ms to decay completely. Tetanic stimulation (100 ms, 100 Hz) produced a depolarizing wave with individual EPSPs superimposed. The absolute amplitude of the individual EPSPs decreased during the train. Spike rates, established by injected current, mostly were increased, but in some cells were decreased, by tetanic stimulation. Global application of a γ-aminobutyric acid-A (GABAA) antagonist to the recorded cell's soma and apical dendritic region increased the EPSP peak and decay phase amplitudes. Tetanic stimulation always increased current-evoked spike rates after GABAA blockade during, and for several hundred milliseconds after, the stimulus. Application of a GABAB antagonist did not have any significant effects on the PF-evoked response. This, and the lack of any long hyperpolarizing inhibitory postsynaptic potentials, suggests that VML and stellate cell inhibition does not involve GABAB receptors. Focal GABAA antagonist applications to the dorsal molecular layer (DML) and pyramidal cell layer (PCL) had contrasting effects on PF-evoked EPSPs. DML GABAA blockade significantly increased the EPSP peak amplitude but not the decay phase of the EPSP, whereas PCL GABAA-blockade significantly increased the decay phase, but not the EPSP peak, amplitude. The order of antagonist application did not affect the outcome. On the basis of the known circuitry of the ELL, we conclude that the distal inhibition originated from GABAergic molecular layer stellate cells and the proximal inhibition originated from GABAergic cells of the ventral molecular layer (VML cells). Computer modeling of distal and proximal inhibition suggests that intrinsic differences in IPSP dynamics between the distal and proximal sites may be amplified by voltage-dependent NMDA receptor and persistent sodium currents. We propose that the different time courses of stellate cell and VML cell inhibition allows them to act as low- and high-pass filters respectively on indirect descending feedback to ELL pyramidal cells.

scholarly journals Stellate cell computational modeling predicts signal filtering in the molecular layer circuit of cerebellum

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Martina Francesca Rizza ◽  
Francesca Locatelli ◽  
Stefano Masoli ◽  
Diana Sánchez-Ponce ◽  
Alberto Muñoz ◽  
...  
Keyword(s):  
Purkinje Cell ◽  
Stellate Cell ◽  
Molecular Layer ◽  
Stellate Cells ◽  
Parallel Fiber ◽  
Cell Discharge ◽  
Physiological Properties ◽  
Low Pass ◽  
Band Pass ◽  
Very High Frequencies

AbstractThe functional properties of cerebellar stellate cells and the way they regulate molecular layer activity are still unclear. We have measured stellate cells electroresponsiveness and their activation by parallel fiber bursts. Stellate cells showed intrinsic pacemaking, along with characteristic responses to depolarization and hyperpolarization, and showed a marked short-term facilitation during repetitive parallel fiber transmission. Spikes were emitted after a lag and only at high frequency, making stellate cells to operate as delay-high-pass filters. A detailed computational model summarizing these physiological properties allowed to explore different functional configurations of the parallel fiber—stellate cell—Purkinje cell circuit. Simulations showed that, following parallel fiber stimulation, Purkinje cells almost linearly increased their response with input frequency, but such an increase was inhibited by stellate cells, which leveled the Purkinje cell gain curve to its 4 Hz value. When reciprocal inhibitory connections between stellate cells were activated, the control of stellate cells over Purkinje cell discharge was maintained only at very high frequencies. These simulations thus predict a new role for stellate cells, which could endow the molecular layer with low-pass and band-pass filtering properties regulating Purkinje cell gain and, along with this, also burst delay and the burst-pause responses pattern.

scholarly journals Stellate cell computational modelling predicts signal filtering in the molecular layer circuit of cerebellum

2020 ◽  
Author(s):  
Martina Francesca Rizza ◽  
Francesca Locatelli ◽  
Stefano Masoli ◽  
Diana Sánchez Ponce ◽  
Alberto Muñoz ◽  
...  
Keyword(s):  
Purkinje Cell ◽  
Stellate Cell ◽  
Molecular Layer ◽  
Computational Modelling ◽  
Stellate Cells ◽  
Parallel Fiber ◽  
Cell Discharge ◽  
Physiological Properties ◽  
Low Pass ◽  
Very High Frequencies

AbstractThe functional properties of cerebellar stellate cells and the way they regulate molecular layer activity are still unclear. We have measured stellate cells electroresponsiveness and their activation by parallel fiber bursts. Stellate cells showed intrinsic pacemaking, along with characteristic responses to depolarization and hyperpolarization, and showed a marked short-term facilitation during repetitive parallel fiber transmission. Spikes were emitted after a lag and only at high frequency, making stellate cells to operate as delay-high-pass filters. A detailed computational model summarizing these physiological properties allowed to explore different functional configurations of the parallel fiber – stellate cell – Purkinje cell circuit. Simulations showed that, following parallel fiber stimulation, Purkinje cells almost linearly increased their response with input frequency but such an increase was inhibited by stellate cells, which leveled the Purkinje cell gain curve to its 4 Hz value. When reciprocal inhibitory connections between stellate cells were activated, the control of stellate cells over Purkinje cell discharge was maintained only at very high frequencies. These simulations thus predict a new role for stellate cells, which could endow the molecular layer with low-pass and band-pass filtering properties regulating Purkinje cell gain and, along with this, also burst delay and the burst-pause responses pattern.

Development of the rodent cerebellum and synaptic re-formation of donor climbing terminals on spines of the host Purkinje dendrites after chemical deafferentation

1990 ◽  
Vol 153 (1) ◽  
pp. 289-303
Author(s):  
K. Kawamura ◽  
S. Murase ◽  
S. Yuasa
Keyword(s):  
Purkinje Cells ◽  
Dendritic Spines ◽  
Ultrastructural Level ◽  
Climbing Fibers ◽  
Normal Brain ◽  
Parallel Fibers ◽  
Synaptic Contacts ◽  
Axonal Sprouts ◽  
Inferior Olivary ◽  
The Brain

Reinnervation of host Purkinje cells by donor climbing fibers was observed in the following experiments. Medullary primordial tissue (from E14-E16) containing the inferior olive was grafted into a host rat cerebellum, in which the inferior olivary complex and climbing fibers had been destroyed by intraperitoneal injection of 3-acetylpyridine (3-AP). After 3 weeks, immature as well as mature types of climbing fiber terminals bearing packed round vesicles were found that had established synaptic contacts on dendritic spines of the host Purkinje cells. Quantitative analysis at the ultrastructural level has been carried out. The main results are as follows. (1) The number of preterminals that formed synaptic contacts with spines of the host Purkinje dendrites in the transplanted material increased by 3.4-fold compared to the control (3-AP-treated non-grafted material). (2) The number of mature climbing-type preterminals increased from 0.3-0.9% to 5% after grafting (cf. 22% in normal brain tissue), and the number of immature climbing-type preterminals also increased from 2–10% (control) to 20% after grafting. These changes were statistically significant (P less than 0.01). (3) The number of parallel-type preterminals increased from 13% (control) to 27% after grafting, which was also statistically significant (P less than 0.01). Thus, it appears that the donor climbing fibers grow and develop to find unoccupied spines on the host Purkinje dendrites and establish synaptic contacts, and also that the host parallel fibers may generate axonal sprouts to search their new targets and ultimately to form synaptic contacts with unoccupied spines. In the process of re-modeling the brain, competition for targets is likely to occur between the two kinds of axonal processes, i.e. the donor climbing fibers and the host parallel fibers.

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.

Biphasic Modulation of GABA Release From Stellate Cells by Glutamatergic Receptor Subtypes

2007 ◽  
Vol 98 (1) ◽  
pp. 550-556 ◽  
Author(s):  
Siqiong June Liu
Keyword(s):  
Glutamate Receptors ◽  
Ampa Receptors ◽  
Gaba Release ◽  
Stellate Cells ◽  
Climbing Fibers ◽  
Receptor Subtypes ◽  
Presynaptic Terminals ◽  
Parallel Fibers ◽  
Release Probability ◽  
Basket Cells

The release of inhibitory transmitters from CNS neurons can be modulated by ionotropic glutamate receptors that are present in the presynaptic terminals. In the cerebellum, glutamate released from climbing fibers (but not from parallel fibers) activates presynaptic AMPA receptors and suppresses the release of the inhibitory transmitter GABA from basket cells onto postsynaptic Purkinje cells. This input-specific modulation has been attributed to the close proximity of the climbing fibers to the axons of the basket cells. Our recent work indicates that glutamate released from parallel fibers can “spill over” and reach the axons of stellate cells. Here I test the possibility that this spillover glutamate can activate presynaptic AMPA receptors in stellate cells and in this way modulate their release of GABA. I find that stimulation of parallel fibers activates AMPA receptors and transiently suppresses autoreceptor and autaptic GABAergic currents in stellate cells. Activation of AMPA receptors reduces the release of GABA and the suppression occurs more frequently in immature cells that have a high release probability. By contrast the release of GABA from mature stellate cells that have a low release probability is potentiated by the activation of NMDA-type glutamate receptors on presynaptic terminals. Thus during development, the glutamatergic modulation of GABA release switches from an AMPA-receptor–mediated transient suppression to a NMDA-receptor–induced lasting potentiation.

scholarly journals Axons from the Trigeminal Ganglia are the Earliest Afferent Projections to the Mouse Cerebellum

2017 ◽  
Author(s):  
Hassan Marzban ◽  
Maryam Rahimi-Balaei ◽  
Richard Hawkes
Keyword(s):  
Purkinje Cell ◽  
Purkinje Cells ◽  
Mossy Fibers ◽  
Cell Plate ◽  
Trigeminal System ◽  
Trigeminal Ganglia ◽  
Afferent Pathways ◽  
Afferent Projections

ABSTRACTThe first stage standard model for the development of afferent pathways to the cerebellum is that ingrowing axons target the embryonic Purkinje cells (E13-E16 in mice). Perinatally and early postnatal (E18-P15) the climbing fibers translocate to the Purkinje cell dendrites, and as the granular layer develops the mossy fibers translocate from the Purkinje cell somata and synapse with granule cell dendrites. In this report we describe a novel earlier stage in the development. Immunostaining for a neurofilament-associated antigen (NAA) reveals the early axon distributions with remarkable clarity. Axons from the trigeminal system enter the cerebellar primordium as early as embryo age (E)9. By using a combination of axon tract tracing, analysis of neurogenin1 null mice – which do not develop trigeminal ganglia – and mouse embryos maintained in vitro – we show that the first axons to innervate the cerebellar primordium are direct projections from the trigeminal ganglia. The data show that the early trigeminal projections are in situ before the Purkinje cells are born, and double immunostaining for NAA and markers of the different domains in the cerebellar primordium reveal that they first target the cerebellar nuclear neurons of the nuclear transitory zone (E9-E10), and only later (E10-E11) extend collateral branches to the Purkinje cell plate.

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