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A Cupello

Publications and source records attributed to A Cupello.

At least 109 records · Page 6Linked to original sources
PubMed1981

On the presence of met 5-enkephalin receptors on the plasma membrane of Deiters' neurons and their modulation of GABA transport.

Met 5-enkephalin blocks the active transport of GABA across plasma membranes of rabbit Deiters' neurons prepared by microdissection. Such an effect is receptor-mediated, being reversed by the antagonist Naloxone. This result shows that Deiters' neurons bear enkephalin receptors, and suggests a hypothesis on the mechanism of enkephalin-mediated neuronal inhibition.

Animals↗
PubMed1981

Modification in messenger RNA population synthesized in rabbit cerebral cortex in the recovery period following convulsions.

The labeling pattern of microsomal poly(A)-associated messenger RNA was studied in rabbit cerebral cortex during the postconvulsive period. Labeled uridine was injected into the brain 2 hr after a single electroconvulsive shock and the animals sacrificed 1 hr later. Poly(A) RNA was then extracted from cerebral cortex microsomes, and fractionated by gel electrophoresis. The results indicate that the messenger RNA population synthesized in the cortex in the postconvulsive recovery period is clearly different from that synthesized in the normal controls.

Animals↗
PubMed1981

Long-lasting effects of electroconvulsive shock on the pattern of poly(A)-RNA synthesis in rabbit cerebral cortex.

The pattern of poly(A)-associated [poly(A)+] RNA synthesis was studied in rabbit cerebral cortex in the period following a single electroconvulsive shock (ECS). Labeled uridine was injected into the brain 2 and 4 hr after ECS and the animals sacrificed 1 hr later. Total and poly(A)+ RNA were then prepared from cortical nuclei and microsomes and analyzed. The amounts of newly synthesized total and poly(A)+ RNA in nuclei and microsomes appeared to be close to the control. However, the pattern of newly synthesized poly(A)+ nuclear RNA appeared to be still displaced toward the high molecular weights as it was in the early post-ECS period. The result indicates a long-lasting disturbance of brain poly(A)+-RNA metabolism by ECS.

Animals↗
PubMed1981

Quantitative EEG and neurochemical aspects of memory and learning.

Different, established or putative animal models of learning were studied by electrophysiological (EEG) and neurochemical methodologies. The training of rats to new behavioral patterns proved to result in the stimulation of total RNA synthesis rate in specific brain structures, as well as in modifications of the EEG organization of hippocampus. This two-fold approach to the assessment of modifications in learning-involved brain structures was extended to the study of mirror focus and kindling, to verify the suitability of these phenomena as experimental models of learning. Reduced (3H) uridine incorporation and proportion of poly (A)-associated RNA were found in mirror focus in comparison with control regions. These variations seem related to brain damage rather than be congruent with learning-related modifications. Further studies are necessary to verify whether the kindling phenomena are to be equated to learning models.

Amygdala↗
PubMed1978

Studies of RNA metabolism in the nerve cells of hippocampus during training in rats.

Direct evidence is presented that training to change behavior initiates synthesis of specific species of mRNA in pyramidal nerve cells of CA3 of the hippocampus in rats. Reversal of handedness was used as goal-directed operant test and active controls. Newly synthesized poly(A) associated mRNA with S value of 25 and a stimulation of poly(A) lacking mRNA of 8--9 S and 16--17 S were found in the CA3 nerve cells of trained but not in active controls.

Animals↗
PubMed1977

A simple system for inspection of microelectrophoretic patterns.

An inexpensive device for inspection of electrophoretic patterns on microgels is described. A common slide frame is modified in order to hold inside microgels immersed in liquid, so that the gels may then be projected on paper screens. The electrophoretic patterns may be drawn on the basis of the gel images. Staff-meeting presentation of microelectrophoretic patterns seems to be another application of the system.

Animals↗
PubMed1977

A comparison of poly (A)-associated RNA from synaptosomes and cytoplasmic subcellular fractions of rat brain.

Oligo(dT)-cellulose binding poly(A)-RNA from rat brain microsomes, mitochondria and synaptosomes was isolated and analysed. Synaptosomes and mitochondria appeared to contain a higher proportion of such RNA than microsomes. Poly(A)-RNA from the three fractions was then electrophoretically fractionated in two different gel systems. Mitochondrial and microsomal poly(A)-RNA presented different fractionation patterns. Synaptosomal poly(A)-RNA also presented a characteristic patterns of its own which could not be entirely explained as a mixture of the previous two. Its main feature was the presence of a prominent band with an SE value of around 7. Such species, absent in microsomes, was present as well in mitochondria but in smaller concentration. On the basis of the present evidence and of previous results, it appears that such 7 SE species, although a mitochondrial messenger RNA in origin, becomes accumulated in vivo into synaptic membranes.

Animals↗
PubMed1976

Fractionation on the microscale of brain polyribosomes by electrophoresis on acrylamide gels.

A method is described for brain polyribosome fractionation by acrylamide gel electrophoresis. Brain polyribosomes were run in 2.0% gels in quartz capillaries of 800 mum inner diameter where the gels were supported by capillary force. The gels could then be ultraviolet-scanned in situ. Amounts of brain polyribosomes as small as 10-10(-3) A260nm unit could be analysed by this method. The method was checked by running a macroscale-prepared brain polyribosome sample. The various electrophoretic bands obtained showed a favourable A260nm: A280 ratio. A short RNase treatment caused the disappearance of the slowly migrating bands and the emergence of a predominant band migrating faster than the dimer. The various polyribosomal bands were then identified by comparison with the mobility of polyribosome fractions taken from a sucrose gradient fractionation. Finally, the electrophoretic pattern of brain polyribosomes compared favourably with the pattern obtained by the classic method of sucrose gradient sedimentation. The electrophoretic fractionation of polyribosomes prepared from one rat hippocampus (80 mg) is presented.

Animals↗
PubMed1976

Alteration of the pattern of hippocampal nerve cell RNA labelling during training in rats.

RNA synthesis in the CA3 region of brain hippocampus was studied in rats trained to a handedness reversal task. The newly synthesized RNA, labelled by intraventricular injection of radioactive orotic acid, was extracted and analyzed by micromethods. The result was following. In the trained animals the incorporation of the labelled precursor into RNA, corrected by the pool radioactivity, was almost double in comparison with the controls. In the trained animals there was a stimulation of the incorporation in the high molecular weight (greater than 18S) RNA region and in two specific low molecular weight regions: 8-9 and 16-17S. Taking in account previous results of other authors, these data appear to imply a stimulation of brain mRNA synthesis as a result of training.

Animals↗
PubMed1976

Pattern of labelling of poly (A)-associated RNA in the CA3 region of rat hippocampus during training.

Newly synthesized poly (A)-associated mRNA was analysed in the hippocampal CA3 pyramidal nerve cells in rats subjected to training to reverse handedness. The nerve cells of trained animals showed a smaller percentage of poly(A)-associated mRNA than did the active controls. However, a specific fraction of this poly (A) hippocampal RNA with a SE value of around 25 was reproducibly stimulated. This qualitative nerve cell mRNA change is discussed in relation to similar changes in the protein pattern as a function of training.

Animals↗
PubMed1976

Poly(A) associated RNA from mitochondria and microsomes of rat brain.

Rat brain mitochondria contain a significant proportion of poly(A) associated RNA which is higher than that found in microsomes from the same source. When steady state poly(A) RNA of brain mitochondria was analyzed by microelectrophoresis, it displayed a characteristic separation pattern with a large amount of "free" poly(A).

Animals↗