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Biomedical subjects

N Schupf

Publications and source records attributed to N Schupf.

43 records · Page 3Linked to original sources

Anaphylatoxin C5a modulation of an alpha-adrenergic receptor system in the rat hypothalamus.

C5a anaphylatoxin injected via implanted cannulae into the perifornical region of the hypothalamus stimulated eating in sated rats. C5a also attenuated carbamyl choline-induced drinking, and carbamyl choline inhibited C5a-induced eating, a mutual inhibition characteristic of the adrenergic-cholinergic interactions at this site. The increased food intake induced by C5a was also reversed by phentolamine, an alpha-adrenergic antagonist. Granulocytes infiltrating as a result of C5a-mediated leukotaxis did not arrive at the site in time to influence C5a activity. We propose that C5a in some way activates an alpha-adrenergic receptor system in the hypothalamus, and that anaphylatoxins could mediate neuropsychiatric symptoms sometimes associated with immune complex diseases affecting the central nervous system.

Animals↗

Psychopharmacological activity of anaphylatoxin C3a in rat hypothalamus.

C3a anaphylatoxin injected into the perifornical hypothalamic region of sated rats increased the eating response to norepinephrine and the drinking response to carbamyl choline but had no effect on food or water intake in sated, saline control animals. This potentiation of drug-stimulated intakes was reversible by intrahypothalamic injection of catecholamine receptor antagonists haloperidol and phentolamine. We propose that C3a acts as a catecholamine agonist in the central nervous system. The results suggest that C3a may play a role in mediating the neuropsychiatric manifestations associated with immune complex formation or deposition in the central nervous system.

Animals↗

Antigen-antibody reactions in rat brain sites induce transient changes in drinking behavior.

The septum or hypothalamus of rat brain was injected through implanted cannulas with antibody against membrane antigens in the rat brain or with antibody against exogenous soluble antigens (such as ovalbumin) followed by the specific antigen. Both immunological systems produced a moderate but highly significant decrease in drinking by thirsty rats. This phenomenon is suggested as an experimental model for behavioral disorders resulting from nondegenerative, immunological processes in the brain.

Animals↗

Uses of double-pulse stimulation behaviorally to infer refractoriness, summation, convergence, and transmitter characteristics of hypothalamic reward systems.

To self-administer trains of pulse pairs, rats with electrodes in the hypothalamic reward system would press a lever at lower current thresholds or faster latencies, the shorter the intrapair interval--unless the interval was so short that each second pulse fell within the refractory period following the first. By delivering all second pulses to the contralateral reward system not only was this refractory period limitation on temporal summation circumvented but spatial summation of the two reward systems was demonstrated. Evidently, they converge somewhere upon common neurons. Nearby nonreward structures did not share in this convergence. Assuming that the temporal-summation decline at longer intrapair intervals reflected the course of transmitter disposal at the synapse, imipramine and diisopropylfluorophosphate were peripherally administered. These drugs, which retard disposal, respectively, in adrenergic and cholinergic synapses, indeed prolonged temporal summation, thus, supporting the assumption and implying that adrenergic and cholinergic mechanisms both mediate self-stimulation.

Acetylcholine↗

Likelihood of pregnancy in individuals with idiopathic/cryptogenic epilepsy: social and biologic influences.

We interviewed 1,558 adults with idiopathic/cryptogenic epilepsy ascertained from voluntary organizations and 316 of their siblings without epilepsy to determine their personal history of marriage and pregnancy. We examined the effects of seizure type, age at onset, and family history of epilepsy on the sex-specific likelihood of pregnancy in individuals with idiopathic/cryptogenic epilepsy as compared with their same-sex siblings. Overall, men with idiopathic/cryptogenic epilepsy were only 36% as likely as male unaffected siblings ever to have fathered a pregnancy. In men, the reduced likelihood of fathering a pregnancy was associated with partial-onset seizures, early age at onset (< 20 years), and a negative family history of epilepsy, and the effects of these epilepsy characteristics appeared to be mediated through reduced marriage rates. Among men with epilepsy who had ever been married, reproductive disadvantage was confined to those with early-onset (< 10 years) partial epilepsy. Overall, women with idiopathic/cryptogenic epilepsy were only 37% as likely ever to have had a pregnancy as female unaffected siblings; this effect was not strongly influenced by seizure type, age at onset, or family history of epilepsy. In women who had ever been married, unlike in men, reduced likelihood of pregnancy persisted, regardless of seizure type, age at onset, or family history of epilepsy.

Adult↗