Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Cerebellar Cortex”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 739 records · Page 41Linked to original sources
PubMed2007

Relationship of complex spike synchrony bands and climbing fiber projection determined by reference to aldolase C compartments in crus IIa of the rat cerebellar cortex.

Synchronous complex spike (CS) activity occurs most often among cerebellar Purkinje cells located in a narrow longitudinal (parasagittal) strip of cortex (synchrony band). The relationship of the anatomical organization of the olivocerebellar projection to these synchrony bands has not been investigated in detail. Thus, we studied this relationship by using the aldolase C (zebrin II) expression pattern, another landmark for the cerebellar longitudinal organization, as a reference frame in rat crus IIa. Crus IIa consists of 10 aldolase C-positive and -negative longitudinal compartments. Aldolase C labeling after multiple-electrode recording of CSs indicated that in lateral crus IIa (compartments 5+ to 7+) synchrony bands were generally constrained to single compartments. In contrast, in medial crus IIa (compartments 4a- to 5a-) the synchrony within and across the compartments was much higher than in lateral crus IIa, resulting in wide synchrony bands covering multiple compartments. Retrograde labeling of olivary neurons by injections of biotinylated dextran amine into aldolase C compartments in crus IIa showed that compartments in medial crus IIa were all innervated by the caudal part of the medial accessory olive. On the other hand, each aldolase C compartment in the lateral crus IIa was innervated by a region in a different subnucleus in the rostral inferior olive. These regions in different subnuclei were located close to each other. These results suggest that CS synchrony bands reflect the olivocerebellar compartmental projection pattern and neuronal coupling within a particular olivary subnucleus, and that medial and lateral crus IIa may be functionally distinct.

Action Potentials↗
PubMed1977

Fine structure of the cerebellar cortex in Menkes Kinky-hair disease. X-chromosome-linked copper malabsorption.

The cerebellar cortices in two patients with X-chromosome-linked copper malabsorption (Menkes kinky-hair disease) were examined with both the light and electron microscope. Somatic sprouts and grotesque dendritic arborization were among the obvious light microscopical changes. At the fine structural level, the Purkinje cells were characterized by the presence of somatic spines although the surviving granule cells had already descended. Most spines were parts of synaptic complexes, but some were unattached to any presynaptic element. Similar spines were also observed on dendritic trunks. Astrocytic gliosis and nonspecific endothelial cell changes were noted.

Axons↗
PubMed1990

Inhibition of barosensitive neurones evoked by lobule IXb of the posterior cerebellar cortex in the decerebrate rabbit.

1. Electrical stimulation of lobule IXb of the posterior cerebellar vermis evoked an increase in heart rate and arterial pressure in the decerebrate rabbit. This pattern of response was followed by a rebound bradycardia which was maintained until arterial pressure had returned to control levels. Activation of the arterial baroreceptors during IXb stimulation failed to elicit reflex changes in heart rate and arterial blood pressure. 2. Extracellular recordings were made from eighty-one single neurones in the nucleus tractus solitarius (NTS), and adjacent structures, that received inputs from the carotid sinus nerve, aortic nerve and/or vagus. A proportion of these were characterized as baro- or chemosensitive by physiological stimuli. The nature of the input from lobule IXb onto these cells was studied subsequently. 3. In twenty-seven out of thirty-five barosensitive neurones, stimulation of lobule IXb either decreased or abolished on-going activity. The latency to onset of inhibition was 21 ms in fourteen cells. In a further twenty-one neurones the spikes evoked orthodromically by electrical stimulation of either the aortic or sinus nerves were either inhibited or severely reduced in number during short-train conditioning stimulation of lobule IXb. This effect was most potent when the cortical conditioning stimulus was timed to occur 25 ms before the aortic or carotid sinus nerves were stimulated. 4. It is suggested that stimulation of lobule IXb in the decerebrate rabbit expresses its influence on the cardiovascular system in part by an inhibitory action on neurones receiving baroreceptor inputs at the level of the NTS.

Animals↗
PubMed1997

Local and propagated vascular responses evoked by focal synaptic activity in cerebellar cortex.

We investigated the local and remote vascular changes evoked by activation of the cerebellar parallel fibers (PFs). The PFs were stimulated (25-150 microA, 30 Hz) in halothane-anesthetized rats equipped with a cranial window. The changes in arteriolar and venular diameter produced by PF stimulation were measured with the use of a videomicroscopy system. Cerebellar blood flow (BFcrb) was monitored by laser Doppler flowmetry and the field potentials evoked by PF stimulation were recorded with the use of microelectrodes. PF stimulation increased the diameter of local arterioles (+26 +/- 1%, mean +/- SE) in the activated folium (n = 10, P < 0.05). The vasodilation was greatest in smaller arterioles (16.5 +/- 0.8 microm), was graded with the intensity of stimulation, and was less marked than the vasodilation produced by hypercapnia in comparably sized vessels (+58 +/- 5%, CO2 pressure = 50-60 mmHg, n = 8). In addition, the vasodilation was greatest along the horizontal beam of activated PFs and was reduced in arterioles located away from the stimulated site in a rostrocaudal direction. The increases in vascular diameter were associated with increases in BFcrb in the activated area (+55 +/- 4%, n = 5). PF stimulation increased vascular diameter (+10 +/- 0.5%, n = 10) also in larger arterioles (30-40 microm) located in the folium adjacent to that in which the PFs were stimulated. Higher-order branches of these arterioles supplied the activated area. No field potentials were evoked by PF stimulation in the area where these upstream vessels were located. The data suggest that increased synaptic activity in the PF system produces a "local" hemodynamic response mediated by synaptic release of vasoactive agents and a "remote" response that is propagated to upstream arterioles from vessels residing in the activated folium. These propagated vascular responses are important in the coordination of segmental vascular resistance that is required to increase flow effectively during functional brain hyperemia.

Animals↗
PubMed1994

High resolution (SE-I) scanning electron microscopy features of primate cerebellar cortex.

This paper provides an exploration into the outer and inner surfaces of primate cerebellar neurons using secondary electron-I (SE-I) topographic contrast. SE-I enriched, chromium coated, cryofractured cerebellum staged within the condenser/objective lens stage of SEMs, equipped with high brightness LaB6 and field emission emitter, generated quality images of intact and fractured nerve cells studied at intermediate and high magnifications. Granule and Golgi cell surfaces revealed smooth, accurately delineated profiles of the true cell surface features, which lacked the SE-III dominated brilliance of conventional gold or gold-palladium decorated images. Fractured non synaptic segments of parallel fibers in the molecular layer showed interconnected anastomotic networks of ER tubules, vesicles and cisterns, whereas cross fractured presynaptic "en passant" endings of these fibers exhibited spheroidal synaptic vesicles and SE-I edge brightness contrast delineated their limiting plasma membranes. Parallel fiber fractured synaptic endings showed a homogeneous extravesicular material surrounding the synaptic vesicles. The neuroglial cytoplasm ensheathing nerve processes exhibited a smooth discontinuous surface. The high mass density surface of the myelin sheath showed a mixed population of globular structures, 10-30 nm, corresponding to protein and phospholipid microdomains.

Animals↗