Search PubMed⌕ Search

Biomedical subjects

R Freedman

Publications and source records attributed to R Freedman.

At least 253 records · Page 14Linked to original sources

Electrophysiological analysis reinnervation of transplants in the anterior chamber of the eye by the autonomic ground plexus of the iris.

Fetal rat hippocampus, cerebellum, and heart were homologously transplanted to the anterior chamber of the eye of adult female recipients. After the grafts were allowed to mature in oculo, ingrowing adrenergic and cholinergic fibers from the iris were activated by changing the illumination of the retina. Electrophysiological recordings from all three types of transplants showed changes similar to those reported for effects of adrenergic and and cholinergic inputs in situ. Pharmacological studies with the transplants indicated that these electrophysiological changes were caused by activation of local muscarinic cholinergic and beta-adrenergic synapses. These data suggest that the intraocular graft is able to induce functional adrenergic and cholinergic inputs from the ground plexus of the iris and support the hypothesis that target organ influences play an important role in synaptogenesis.

Action Potentials↗

Trends in fertility, family size preferences, and family planning practice: Taiwan, 1961-76.

A series of six sample surveys and vital statistics are used to analyze major reproductive trends for 1961-76 in Taiwan. Fertility fell rapidly during 1961-70 as a result of adoption of contraception and rising age at marriage, while there was little change in preferred family size. Between 1970 and 1976 the practice of contraception reached high levels in all social strata, and preferred family size and fertility both declined rapidly. Practice of contraception for spacing births increased considerably after 1970. These changes occurred while many traditional familial values, including strong son preference, persisted. A continuation of the decline in fertility is predicted.

Adolescent↗

Electrophysiology and cytology of hippocampal formation transplants in the anterior chamber of the eye. I. Intrinsic organization.

Pieces of the immature hippocampal formation were transplanted to the anterior chamber of adult rat eyes. The transplants survived, became vascularized from the host irides, and proliferated extensively in proportion to the age of the donor fetus. These transplants mature and develop an adult organization in oculo. This maturation proceeds unimpaired in the absence of gyrus dentatus or after superior cervical ganglionectomy.

Animals↗

Interactions of antipsychotic drugs with norepinephrine and cerebellar neuronal circuitry: implications for the psychobiology of psychosis.

Using the rat cerebellar Purkinje cell as a model neuronal system, the effects of norepinephrine and fluphenazine, an antipsychotic drug, are examined. Fluphenazine is shown to be a potent, specific antagonist of the norepinephrine-mediated inhibition of Purkinje cell discharge. Norepinephrine, despite its inhibitory action on spontaneous firing of the Purkinje cell, increases its responsiveness to afferent synaptic pathways. These data thus imply that norepinephrine may increase the brain's sensitivity to incoming information, and that antipsychotic drugs interfere with this effect. A role for norepinephrine, as well as dopamine, in the genesis of psychosis is suggested on the basis of their mutual antagonism by anti-psychotic drugs. The facilatory effects of NE on neuronal information-processing are used to predict a possible participation of NE in the perceptual difficulties noted in psychosis.

Action Potentials↗

The role of Mycoplasma in human infertility.

Seminal fluid from males complaining of infertility was examined for the presence of T-mycoplasmas and Mycoplasma hominis. No significant difference, with regard to the presence of mycoplasmas, was found between the seminal fluid which had normal cytology and seminal fluid of which the cytology was deemed pathological. Colonisation was shown to be an evanescent phenomenon, and female consorts often had different mycoplasma flora to the males. No positive role of mycoplasmas in the pathogenesis of infertility could be shown.

Cervix Uteri↗

Biofeedback and progressive relaxation treatment of sleep-onset insomnia: a controlled, all-night investigation.

Previous research suggests that self-defined insomniacs are distinguished from normals by high levels of anxiety and physiological arousal, which might be mitigated by muscle relaxation. This study assessed the relative effects of frontal EMG biofeedback, progressive relaxation, and a placebo set of "relaxation" exercises on the sleep of 18 onset insomniacs. Each subject was trained in one of these three methods for six half-hour sessions and slept in the laboratory for two consecutive nights before and after training. The experimental groups demonstrated significant decreases in physiological activity during training while changes in the control group were minimal. Reductions in sleep-onset time were: biofeedback group, 29.66 minutes; progressive relaxation group, 22.92 minutes; control group, 2.79 minutes. The experimental groups improved significantly (p less than 905) more than the control group, but did not differ from each other. No significant relationships between physiological levels and sleep-onset time were found, which suggests that muscle relaxation alone was not responsible for subjects' improvements. Since 20 minutes of daily practice were required to achieve an approximate 30-minute decrease in sleep-onset time, the practical utility of the methods is questioned.

Adolescent↗