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Biomedical subjects

G Ferraro

Publications and source records attributed to G Ferraro.

At least 109 records · Page 6Linked to original sources
PubMed1986

Hippocampal seizures and striatal regulation: a possible functional pathway.

Experimental findings have suggested the possibility of a functional relationship between the basal ganglia and the hippocampus. Previous research has revealed a predominantly inhibitory action of the caudate nucleus (CN) and an excitatory effect of the globus pallidus (GP) on electrically induced hippocampal afterdischarges (HAD). The effects of electrolytic destruction of the CN on the threshold and duration of HAD has been studied in the 'encéphale isolé' cat. The threshold and duration of HAD was also studied following conditioning stimulation of the CN in animals in which the inner segment of the globus pallidus (GPi) and medial septal nucleus (MSN) had been destroyed. Following CN lesions, the hippocampal excitability threshold underwent a significant reduction, while the duration of HAD appeared to be increased. Following destruction of the GPi and MSN, the threshold and duration of HAD exhibited no change following conditioning stimulation of the CN. The results reveal a tonic inhibitory effect of the CN on the hippocampus and suggest that a strio-pallido-septal pathway is the anatomical substrate for the effect.

Animals↗
PubMed1986

Modulation of paroxysmal activity in the hippocampus by caudate stimulation in the chronic cat.

Afterdischarges in the dorsal hippocampus (HADs) were studied in freely-moving cats with implanted electrodes following threshold stimulation of the mirror-image point on the contralateral side. Marked inhibition, similar so that seen in acute animals, was observed when the test stimulation was immediately preceded by a conditioning stimulus applied to the caudate nucleus. The inhibitory effect appeared to be larger in these chronic animals than in the acute preparations previously studied, probably because of the total absence of anaesthesia during the recording session. When the HAD is preceded by caudate stimulation, its duration can be graduated by the intensity of the hippocampal test stimulation. The results are discussed in terms of a possible modulation induced directly or indirectly by the caudate nucleus in the hippocampus, which reacts in a gradual manner to the excitatory volley.

Action Potentials↗
PubMed1986

Relations between basal ganglia and hippocampus: action of substantia nigra and pallidum.

Several interrelationships exist between basal ganglia and hippocampus. The ventral striatum appears to be involved in the control of the dopaminergic nigro-striatal pathway. The caudate, in turn, seems to influence the hippocampal theta rhythm and to inhibit hippocampal spikes. In the present work the role played by globus pallidus pars interna and substantia nigra pars compacta on hippocampal bioelectrical activity is studied. Injection of sodium penicillin i.v. produces steady interictal spikes in the hippocampus. Substantia nigra stimulation induces regular theta rhythm and inhibits the spikes. Pallidal stimulation, on the contrary, appears to strongly enhance epileptiform activity, proceeding to generalised seizure activity. The results are discussed in the light of a putative feedback loop from basal ganglia to hippocampus, probably underlying co-participation of the two subcortical structures in the control of motor behaviour.

Animals↗
PubMed1985

Striatal and septal influence on hippocampal theta and spikes in the cat.

The experiments studied the modulation exerted by the septum and the caudate nucleus on hippocampal activity in the cat. Injections (i.v.) of sodium penicillin were performed in order to obtain a steady interictal epileptic activity. Hippocampal slow rhythmic activity showed a marked decrease either in duration or in frequency following penicillin activation. Both septal and caudate electrical stimulation inhibited spike frequency through a theta eliciting mechanism. Caudate stimulation failed to determine any sort of effect after medial septum lesions. The importance of the septum as modulation station between basal ganglia and hippocampus is emphasized.

Animals↗
PubMed1985

Effects of substantia nigra stimulation on electrical and mechanical activities of the duodeno-jejunal loop, in the cat.

The effect of substantia nigra stimulation on duodeno-jejunal intraluminal pressure and electrical activity was analysed in the cat. An inhibitory influence was noted to occur on both the intestinal pressure and the electrical response activity (ERA): the effect seemed to be in correlation with the stimulus parameters employed. After bilateral vagotomy, the inhibition remained substantially unchanged. The possibility of the existence of a sympathetic pathway mediating the effect is emphasized.

Animals↗
PubMed1984

[Sister chromatid exchanges induced in human lymphocyte chromosomes by trifluralin, atrazine and simazine].

Many epidemiological and experimental "in vivo" studies have proved in recent years the carcinogenic properties of herbicides. In order to evaluate the "in vitro" action on the human DNA of Trifluralin, Atrazine and Simazine (active principles of herbicides Treflan and Fogard S respectively) the authors have studied the rates of SCE in cultures of human lymphocytes exposed to different concentrations of a solution 1 ppm of the substances. Trifluralin and Simazine, but not Atrazine, increase SCE per cell, with statistical significance, in the cultures with the highest concentrations of these substances. (SCE per cell: Trifluralin 5.27 +/- 1.38, Simazine 5.09 +/- 1.19, Control 3.51 +/- 1.14).

Atrazine↗
PubMed1984

[Effects of phototherapy with blue light on chromosomes from human lymphocytes].

The dangerous effects of phototherapy have been matter of discussion in recent years. In order to evaluate its in vitro action on the human DNA, the authors have performed the karyotypic analysis on 20 cultures of lymphocytes. In different times 16 cultures have been exposed to the action of a "blue light" fluorescent lamp, commonly used for the treatment of neonatal jaundice. The authors have not evidenced any morphological or numerical change of the karyotype in any of the cultures.

Adult↗