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Biomedical subjects

M A Persinger

Publications and source records attributed to M A Persinger.

At least 271 records · Page 15Linked to original sources

Religious and mystical experiences as artifacts of temporal lobe function: a general hypothesis.

Mystical and religious experiences are hypothesized to be evoked by transient, electrical microseizures within deep structures of the temporal lobe. Although experiential details are affected by context and reinforcement history, basic themes reflect the inclusion of different amygdaloid-hippocampal structures and adjacent cortices. Whereas the unusual electrical coherence allows access to infantile memories of parents, a source of good expectations, specific stimulation evokes out-of-body experiences, space-time distortions, intense meaningfulness, and dreamy scenes. The species-specific similarities in temporal lobe properties enhance the homogeneity of cross-cultural experiences. They exist along a continuum that ranges from "early morning highs" to recurrent bouts of conversion and dominating religiosity. Predisposing factors include any biochemical or genetic factors that produce temporal lobe lability. A variety of precipitating stimuli provoke these experiences, but personal (life) crises and death bed conditions are optimal. These temporal lobe microseizures can be learned as responses to existential trauma because stimulation is of powerful intrinsic reward regions and reduction of death anxiety occurs. The implications of these transients as potent modifiers of human behavior are considered.

Culture↗

Lead in the water supply alters swimming-maze behavior in adult mice.

After about two weeks of exposure to either 20 ppm or approximately 2000 ppm of lead in the drinking water or tap water only and under an ad libitum or restricted food regime, albino male and female mice (N = 48) were tested for three consecutive days (3 blocks of 3 trials per day) in a swimming maze. Body weights were not altered by lead treatments significantly. The mice treated with the lead displayed longer escape latencies and more errors than the controls on tap water. Statistically significant interactions of lead treatment by test day by test block were also apparent.

Animals↗

Interactions of 2-ppm lead in the water supply with food deprivation upon maze-swimming behavior of mice.

Mice that had been given either tap water or 2 ppm lead in their drinking water and either severely food deprived (3 days before testing) or allowed food ad libitum demonstrated significant interactions of lead treatment by day by food condition and lead by block. Although not statistically significant, the food deprived-lead treated mice displayed more errors and longer latencies than the ad libitum-water controls. The food deprived-water controls and ad libitum-lead-treated mice displayed intermediate values. The importance of using multivariate statistical techniques that can evaluate dynamic repeated behavioral measurements is emphasized.

Animals↗

Developmental alterations in mast cell numbers and distributions within the thalamus of the albino rat.

A total of 216 male and female albino Wistar rats (Rattus norvegicus) between 10 and 60 days old from 42 litters were studied to determine mast cell characteristics within the thalamus. Whereas the mean numbers of mast cells within both the parenchyma and leptomeninges (combined) did not change appreciably after 15 days of age, the appearance of mast cells within the parenchyma (and disappearance from the leptomeninges) is clearly age-dependent. Between 15 and 25 days of age, the relative numbers of mast cells within the thalamic parenchyma changed from 20 to 90% of the total mast cells within thalamic space.

Aging↗

Long-term effects of preweaning taurine injections in rats: interactions with strain and gender.

A comparison was made of MR, MNR, and RCA strains that had been injected with either 62.5 mg/kg of taurine or comparable volumes of physiological saline between postnatal Days 8 and 20 and later tested at 100 days of age in an open field and 1-way shock avoidance situations. Taurine-injected rats displayed significant elevation in defecation score in the open field. In addition a significant Treatment X Strain interaction was due to the larger defecation numbers displayed by the taurine-injected MR rats relative to the saline-injected MR rats.

Animals↗

A first order approximation of satiation time: (IRT)2/Rt.

Habituation, satiation, adaptation, and boredom are a few of the words used to label the behavioral consequences of a fundamental operation: repeated and protracted presentation of a stimulus. The cumulative measure of the response associated with that stimulus is expected to display an inflection at some time Ti after which the slope approaches zero. Ti can be estimated by dividing the square of the interresponse time (IRT)2 by the duration of the response associated with reinforcement (Rt), where Rt is expressed in the nearest whole temporal unit of interresponse time. Calculated TiS for habituation to the same sexual, aggressive, or social stimuli are compatible with general observation.

Habituation, Psychophysiologic↗

Mesenteric mast cell degranulation is not essential for conditioned taste aversion.

The possible role of mesenteric mast cell degranulation as the mediator of the initial UCS effects in the complex sequences leading to conditioned taste aversion (CTA) was studied. Both LiCl and Compound 48/80, a potent mast cell degranulator, produced CTA to 10% sucrose. Whereas the Compound 48/80 groups displayed massive mast cell degranulation, neither the LiCl treated nor saline control groups demonstrated any histologically determinable alterations. Administration of the antihistamine chlorpheniramine at dosages known to block radiation-induced CTA before the sucrose CS-UCS pairings did not block either LiCl- or Compound 48/80-induced CTA; the antihistamine actually facilitated the aversion. However, pretreatment with the antihistamine did not alter mesenteric mast cell morphology.

Animals↗