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Biomedical subjects

G Serra

Publications and source records attributed to G Serra.

At least 163 records · Page 9Linked to original sources
PubMed1979

Evidence that a nigral gabaergic--cholinergic balance controls posture.

The intranigral injection of kainic acid (k.a.) (3.5 nM/s.n.) produced a lesion which resulted in a decreased muscarinic receptor binding capacity and in a decreased choline acetyl transferase (CAT) activity confined to the pars reticulata. The unilateral, intranigral injection of carbachol in the substantia nigra (s.n.) produced turning, ipsilateral to the injected side, of dose-related intensity, which was antagonized by scopolamine given either i.p. or intranigrally together with carbachol. The bilateral, intranigral injection of carbachol produced rigid catalepsy, highly resistant to apomorphine administration and antagonized by scopolamine. On the other hand, the catalepsy produced by intranigral picrotoxin was much more sensitive to apomorphine and was disrupted by systemic scopolamine administration. Intranigral scopolamine per se produced either contralateral turning or stereotyped movements consistently, when injected unilaterally or bilaterally, respectively. In addition, scopolamine injected bilaterally in the s.n. but not in the caudate nucleus (c.n.), at the concentration of 64 nM side, was able to antagonize the haloperidol-induced catalepsy and to prevent the tremors and the muscular rigidity produced by arecoline. This effect of scopolamine was surmountable with a higher dose of arecoline. Finally, intranigral muscimol (0.44 nM/s.n.) prevented the occurrence of the parkinsonian syndrome produced by systemic arecoline. It is concluded that the muscarinic receptors present in the s.n. pars reticulata play a role in the control of posture opposite to that of the nigral GABA receptors.

Animals↗
PubMed1979

Foot-shock stress accelerates non-striatal dopamine synthesis without activating tyrosine hydroxylase.

Electric foot-shock stress (20 min) increases DOPAC content in the frontal cortex (by about 80%) and in the nucleus accumbens (by 35%) but not in the striatum. However, foot shock stress failed to modify the kinetic properties of tyrosine hydroxylase (Vmax, Km for DMPH4 cofactor) in any of the above areas. Similar results were obtained in rats in which noradrenergic terminals in the n. accumbens and in the frontal cortex had been eliminated by injection of 6-OH-dopamine into the ascending dorsal noradrenergic bundle. The results support the hypothesis that limbic and cortical DA is involved in emotional states and indicate that DA synthesis may be regulated independently from changes in the kinetics properties of tyrosine hydroxylase.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1978

[Fibrochondrogenesis].

Fibrochondrogenesis is a lethal form of dwarfism similar to thanatophoric dwarfism. It is distinguished radiologically by the widening of the metaphyses of the long bones, and, on lateral x-ray of the spine, by a median fissure of the body of the vertebra without any loss of vertebral height. The condition is inherited an autosomal recessive. A study of growing cartilage confirms that this disease is a distinct entity as there is fibrosis of the cartilage which is never present in thanatophoric dwarfism or in the different forms of achondrogenesis.

Bone Diseases, Developmental↗