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Biomedical subjects

D M Psatta

Publications and source records attributed to D M Psatta.

At least 19 recordsLinked to original sources
PubMed1989

Vasotocin improves intelligence and attention in mentally retarded children.

In mentally retarded (MR) prepubertal children, investigated both before and after six months of treatment, synthetic arginine vasotocin (AVT) (10(-6) mg/day/0.1 ml, intranasally), but not oxytocin or saline alone, significantly increased the intelligence quotient (IQ) and improved the attention parameters without affecting the short-term memory. Taking into account both the psychometric results and the clinical observations, the effects of AVT could be mainly explained by assuming the improvement of attention. Since there was a significant inverse correlation between the pretreatment levels of the IQ and attention scores and their increase after AVT, and since the AVT effects tend to be more intense in autistic children, we hypothesize that the more affected the attention mechanisms, the more they are sensitive to AVT. The present results are tentatively explained by the paradoxical sleep-enhancing properties of AVT, mechanisms by which AVT could improve the brain plasticity in MR subjects and by this, the attention performance.

Attention↗
PubMed1983

Control of chronic experimental focal epilepsy by feedback caudatum stimulations.

The effects of feedback caudate nucleus (CN) stimulations (5 cycles/s, 0.3 ms, 1-5 V, 1-3 s) on the interictal spiking activity of epileptic foci automatically detected by a neuroanalyzer were followed in adult cats during 2-3 weeks of training. Spike depression occurred instantly after the onset of feedback stimulation, became stable after 3-4 days of operant training, and persisted with very little current reinforcement in a daily training schedule. No comparable effects were obtained either by random CN stimulation or by contingent stimulations of other subcortical structures such as the thalamus, the mesencephalic reticular formation, or the hypothalamus. A recovery of recurrent inhibitory caudate-cortical loops is presumed to contribute to the progressive normalization of cortical excitability obtained by training.

Animals↗
PubMed1981

Visual evoked potential habituation in mental deficiency.

Habituation of visual evoked potentials (VEPs) may be a helpful tool in the comparative investigation of mental and neural physiologic processes. Through-train and across-train procedures of VEP averaging were performed during habituation in three groups of male children exhibiting mental retardation (idiopathic, exogenous, chromosomal) and in normal children. The children with idiopathic and exogenous mental retardation reached the same VEP habituation level as the normal children (amplitude reduction of 20-60% of early and late VEP components). The across-train averaging showed however a slower than normal development of habituation in these mentally retarded subjects. Habituation failed to occur in the low-grade mentally retarded children, who displayed a reverse tendency of increasing VEP amplitudes and of VEP variability during repetitive flash applications.

Adaptation, Ocular↗
PubMedDate not supplied

Age-dependent amplitude variation of brain-stem auditory evoked potentials.

Normative amplitude values of brain-stem auditory evoked potential (BAEP) components are given for normally hearing subjects at 1, 10, 30, 50 and 70 years of age, with an intragroup age variation of only +/- 6 months. Under these circumstances amplitude standard deviations decreased to less than 20% of the mean values. In contrast with the reduced evolution of latency with age, BAEP amplitude (for components I-V) undergoes a greater oscillation during ontogeny. With the exception of component I, it increased markedly from 1 year to 10 years of age and decreased thereafter constantly up to 50 years, with a mean rate of 10 nV yearly. The decrease slowed down between 50 and 70 years. The amplitude differences between the subgroups are highly significant statistically (P less than 0.01). Possible reasons for these changes are discussed.

Adolescent↗
PubMedDate not supplied

Effects of feedback caudate nucleus stimulation on spontaneous fast amygdaloid spindles and drive.

Experiments with single and repetitive stimulation of the head of the caudate nucleus (4-10 V, 0.3 msec) triggered by occurrence of fast amygdaloid spindles (35 c/s microV, 0.5 sec) were performed in six animals with chronically implanted cerebral electrodes. In conjunction with the anterior cortical recruiting response the stimulation increased the incidence of amygdaloid fast spindles and decreased the incidence of hippocampal theta activity and of searching eye movements. The associative training failed, however, to significantly modify in the background EEG, the mean incidence of the fast amygdaloid spindles or the rate of the sensorimotor rhythm of 12-18 c/s. Its only effect (after long repetition) was a displacement to the right of the regression line of the incidence of the two rhythms and a slight alteration in the slope. The possibility of activating the caudate nucleus inhibitory effects through the amygdala during internal inhibition phenomena is discussed.

Amygdala↗