Parallel fiber and white matter activation of Purkinje cells in a reptilian cerebellum (Lacerta viridis)

1970 ◽  
Vol 22 (3) ◽  
pp. 381-385 ◽  
Author(s):  
D.T. Kennedy ◽  
T. Shimono ◽  
S.T. Kitai
Keyword(s):  
White Matter ◽  
Purkinje Cells ◽  
Parallel Fiber ◽  
Lacerta Viridis

scholarly journals Degenerative axonopathy associated with copper deficiency in pigs

2017 ◽  
Vol 37 (9) ◽  
pp. 911-915 ◽  
Author(s):  
Roberio G. Olinda ◽  
Lisanka A. Maia ◽  
Maria T.S. Frade ◽  
Mauro P. Soares ◽  
Severo S. Barros ◽  
...  
Keyword(s):  
White Matter ◽  
Purkinje Cells ◽  
Copper Deficiency ◽  
Clinical Signs ◽  
Atomic Absorption Spectrophotometry ◽  
Semiarid Region ◽  
Spastic Paralysis ◽  
Myelin Sheaths ◽  
Cu Deficiency ◽  
Spinal Segments

ABSTRACT: The epidemiological, clinic and morphological (pathological and ultrastructural) aspects of four outbreaks of copper deficiency affecting 21- to 90-day-old pigs in the Northeast region of Brazil are reported. Clinical signs began with paraparesis and ataxia and progressed to flaccid or spastic paralysis of the pelvic and thoracic limbs, followed by sternal and/or lateral recumbence. In addition, some animals showed dog-sitting position and intention tremors. The clinical manifestation period was 5-20 days. Significant gross lesions were not observed; however, microscopically, symmetrical degeneration of the white matter with ballooned myelin sheaths containing occasional macrophages was observed, mainly in the spinal cord. Two pigs presented with necrosis ad loss of Purkinje cells and ectopic Purkinje cells in the granular layer and cerebellar white matter. A ultrastructural analysis showed different degrees of damage of myelinated axons in the spinal segments, including an absence of the axoplasm structures with only axonal residues remaining. The myelin sheaths were degenerated and often collapsed into the space previously occupied by the axon. These results suggest that myelin degeneration is secondary to the axonal lesion. Finally, the concentration of copper in the liver was determined using atomic absorption spectrophotometry and was found to be low (ranging from 2.2 to 10.8 ppm). In conclusion, in the Brazilian semiarid region, Cu deficiency occurs in 21 to 90-day-old pigs that ingested different types of waste in their food.

Immunohistochemical distribution of alpha B-crystallin in the cerebellum of dogs infected with canine distemper virus

2008 ◽  
Vol 56 (1) ◽  
pp. 117-123 ◽  
Author(s):  
Tolga Guvenc ◽  
Murat Yarim ◽  
Mustafa Gulbahar ◽  
Yonca Kabak
Keyword(s):  
White Matter ◽  
Purkinje Cells ◽  
Glial Cells ◽  
Negative Correlation ◽  
Canine Distemper Virus ◽  
Grey Matter ◽  
Significant Negative Correlation ◽  
Canine Distemper ◽  
Αb Crystallin ◽  
Number Of Cells

The cerebella of 12 dogs infected with canine distemper virus (CDV) and those of three normal dogs were examined. The avidin-biotin-peroxidase complex technique was used to detect αB-crystallin (αB-c) immunoreactivity and immunolocalisation of the CDV antigen. CDV antigens, immunopositive astrocytes, oligodendrocytes and granular neurons were seen in both the white and grey matter of the infected dogs. In the controls, αB-c immunopositive glial cells were seen in the white matter and around the Purkinje cells. In dogs with distemper, αB-c immunoreactivity was not observed in some of the glial cells around the Purkinje cells. A significant negative correlation of P < 0.01 level was found between areas of severe demyelination and the number of αB-c immunopositive cells in dogs infected with CDV. Such correlation was not observed between mild and moderate demyelinating areas and αB-c immunostaining. The αB-crystallin/total number of cells ratio was found to be significant in severely affected demyelinating areas (P < 0.05). These data indicate that there was a relationship between the degrees of CDV associated with demyelination and the level of αB-c expression in the glial cells.

Postsynaptic Current Mediated by Metabotropic Glutamate Receptors in Cerebellar Purkinje Cells

1998 ◽  
Vol 80 (2) ◽  
pp. 520-528 ◽  
Author(s):  
Filippo Tempia ◽  
Maria Concetta Miniaci ◽  
Davide Anchisi ◽  
Piergiorgio Strata
Keyword(s):  
Glutamate Receptors ◽  
Purkinje Cells ◽  
Metabotropic Glutamate Receptors ◽  
Parallel Fiber ◽  
High Concentration ◽  
Metabotropic Glutamate ◽  
Group I ◽  
Cerebellar Purkinje Cells ◽  
Mglur Antagonist ◽  
Fiber Stimulation

Tempia, Filippo, Maria Concetta Miniaci, Davide Anchisi, and Piergiorgio Strata. Postsynaptic current mediated by metabotropic glutamate receptors in cerebellar Purkinje cells. J. Neurophysiol. 80: 520–528, 1998. In rat cerebellar slices, repetitive parallel fiber stimulation evokes an inward, postsynaptic current in Purkinje cells with a fast component mediated by α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate receptors and a slower component mediated by metabotropic glutamate receptors (mGluR). The mGluR-mediated excitatory postsynaptic current (mGluR-EPSC) is evoked selectively by parallel fiber stimulation; climbing fiber stimulation is ineffective. The mGluR-EPSC is elicited most effectively with increasing frequencies of parallel fiber stimulation, from a threshold of 10 Hz to a maximum response at ∼100 Hz. The amplitude of the mGluR-EPSC is a linear function of the number of stimulus pulses without any apparent saturation, even with >10 pulses. Thus mGluRs at the parallel fiber-Purkinje cell synapse can function as linear detectors of the number of spikes in a burst of activity in parallel fibers. The mGluR-EPSC is present from postnatal day 15 and persists into adulthood. It is inhibited by the generic mGluR antagonist (RS)-a-methyl-4-carboxyphenylglycine and by the group I mGluR antagonist (RS)-1-aminoindan-1,5-dicarboxylic acid at a concentration selective for mGluR1. Although the intracellular transduction pathway involves a G protein, the putative mediators of mGluR1 (phospholipase C and protein kinase C) are not directly involved, indicating that the mGluR-EPSC studied here is mediated by a different and still unidentified second-messenger pathway. Heparin, a nonselective antagonist of inositol-trisphosphate (IP3) receptors, has no significant effect on the mGluR-EPSC, suggesting that also IP3 might be not required for the response. Buffering intracellular Ca2+ with a high concentration of bis-( o-aminophenoxy)- N,N,N′,N′-tetraacetic acid partially inhibits the mGluR-EPSC, indicating that Ca2+ is not directly responsible for the response but that resting Ca2+ levels exert a tonic potentiating effect on the mGluR-EPSC.

Saccadic eye movements evoked by microstimulation of the fastigial nucleus of macaque monkeys

1988 ◽  
Vol 60 (3) ◽  
pp. 1036-1052 ◽  
Author(s):  
H. Noda ◽  
S. Murakami ◽  
J. Yamada ◽  
J. Tamada ◽  
Y. Tamaki ◽  
...  
Keyword(s):  
Eye Movements ◽  
White Matter ◽  
Purkinje Cells ◽  
Saccadic Eye Movements ◽  
The Other ◽  
Fastigial Nucleus ◽  
Threshold Region ◽  
Other Hand ◽  
Low Threshold ◽  
Stimulation Of

1. Systematic exploration throughout the deep cerebellar nuclei and white matter disclosed that the region from which saccadic eye movements (saccades) were evoked with weak currents (less than 10 microA) was confined to the fastigial nucleus and the adjacent white matter. 2. When an electrode for stimulation was advanced in the cerebellum, saccades were evoked in the direction of the stimulated side (ipsilateral saccades) as it entered the low-threshold region. In some tracks, particularly when the electrode was advanced in the medial portion of the fastigial nucleus, the direction of the evoked saccades changed from the ipsilateral to the contralateral. 3. The mappings with microstimulation disclosed that the ipsilateral saccades were elicited from a relatively wide region that included almost the full extent of the fastigial nucleus. The low-threshold region continued in the white matter caudally into vermal lobule VII and rostrally into the dorsal aspect of the brachium conjunctivum. On the other hand, the contralateral saccades were evoked from a relatively circumscribed region in the ventromedial portion of the fastigial nucleus. 4. The reversal in the direction of the horizontal component occurred always in a narrow zone in the core of the fastigial nucleus. The caudal part of this zone coincided with an ellipsoidal region where anterogradely labeled axons of the Purkinje cells terminated when HRP was injected into vermal lobule VII. 5. When bicuculline (0.2-1 microgram) was injected in the ellipsoidal region, the ipsilateral saccades evoked from the dorsocaudal aspect of the region were suppressed for several hours. On the other hand, the contralateral saccades evoked from the ventromedial portion of the fastigial nucleus were either unchanged or enhanced. 6. Because the ipsilateral saccades were suppressed by bicuculline, they were most probably evoked by stimulation of the presynaptic component of gamma-amino-butyric acid-(GABA) mediated synapses, namely the axons of Purkinje cells. 7. Because stimulation of the presynaptic component of the inhibitory synapses evoked ipsilateral saccades, activation of the postsynaptic component would evoke contralateral saccades. In fact, the distribution of the fastigial sites yielding contralateral saccades coincided with the course of axons of fastigial neurons arising in the ellipsoidal region. It is most likely, therefore, that the contralateral saccades were evoked by stimulation of fastigial neurons.(ABSTRACT TRUNCATED AT 400 WORDS)

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