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Biomedical subjects

M A Persinger

Publications and source records attributed to M A Persinger.

At least 73 records · Page 4Linked to original sources
PubMed2001

Agonistic behavior in groups of limbic epileptic male rats: pattern of brain damage and moderating effects from normal rats.

Different ratios of normal male rats and male rats in which limbic seizures had been induced by a single systemic injection of lithium and pilocarpine were housed in groups of six. The group ratios ranged along the continuum from all normal rats to all experimental rats. The average numbers of episodes of boxing, biting and mounting--thrusting per rat per hour per group were recorded by direct observation (red light) for 1 h during the midscotophase. Groups that contained less than two normal rats exhibited significantly elevated amounts of agonistic (boxing, biting) behavior but not mounting behavior. Multiple regression analyses showed that combinations of neuronal loss within only two to three areas accommodated at least 50% of the variance in the numbers of these behaviors.

Agonistic Behavior↗
PubMed2001

Diurnal variation in pilocarpine-induced generalized tonic-clonic seizure activity.

The efficacy of the cholinergic agonist pilocarpine to evoke generalized seizures in rats was examined over the 24-h photocycle. Both seizure latency and severity during the 24-h period exhibited marked diurnal variation. Seizure activity generalized more rapidly throughout the dark phase and was often characterized by wild running clonus and tonic extensor convulsions. In contrast, electrographic seizures during the light phase were mainly associated with facial/forelimb clonus and rearing typical of pilocarpine-induced seizures. These data suggest that the sensitivity of the rodent brain to pilocarpine exhibits day-night variation and seizure activity induced during the dark phase may generalize via the brainstem.

Animals↗
PubMed2001

Geophysical variables and behavior: XCI. Ambulatory behavior in rats following prenatal exposures to complex magnetic fields designed to interact with genetic expression.

A total of 45 litters were exposed during their entire prenatal development to one of two complex patterns of magnetic fields whose strengths varied within one of four intensity ranges between 10 nT and 1,000 nT or to sham-field conditions. The litters exposed to the most complex pattern, composed of 50 200-msec. presentations of different pulses for 10 sec. every 50 sec., displayed more ambulation in an open field at 21 days of age than the litters that had been exposed continuously to a repetitive frequency-modulated field or to sham-field conditions. This treatment explained 25% of the variance in the numbers of squares traversed. The results suggest that complexity of the applied magnetic field during prenatal development may be more important than intensity for permanently affecting neuronal organization and behavior.

Animals↗
PubMed2001

Experiences of spiritual visitation and impregnation: potential induction by frequency-modulated transients from an adjacent clock.

A left-handed Roman Catholic female adolescent with a history of early brain trauma reported nightly visitations by a sentient being. During one episode she experienced vibrations of the bed, an external presence along the left side that moved into her body, inner vaginal (not clitoral) and uterine sensations, and the sense of being impregnated by a force she attributed to the Holy Spirit. After the latter experience she felt an invisible baby superimposed upon her left shoulder. Analyses of the measurements for magnetic anomalies within her bedroom indicated an electric clock about 20 cm from her head while she slept. The complex form of the 4 microT magnetic pulses generated by the clock was similar to shapes that evoke electrical seizures in epileptic rats and sensitive humans.

Adolescent↗
PubMed2001

Shifting gustatory thresholds and food cravings during pregnancy as expanding uterine-induced steady potential shifts within the insula: an hypothesis.

A logical extrapolation from the principle that structure dictates function is that transient or anomalous experiences are consequences of simultaneous stimulations of proximal brain regions not typically co-activated. In this paper the occasional shifts in gustatory threshold during the menstrual cycle, the craving for unusual tastes experienced by some during pregnancies, and, the reports by postmenopausal women of the "burning mouth syndrome" are hypothesized to be artifacts of the proximity of gustatory and uterine representations within the female insula. Transient (menstrual) or tonic (pregnancy) stimulation within the uterus might shift the locus of neuronal activity within the insula to include adjacent gustatory neurons and consequently alter taste experiences. Specific tests of this hypothesis are suggested.

Adult↗
PubMed2001

Brief successive temporal observational sampling as a possible indicator of daily overt seizure activity in epileptic rats.

Chronic, limbic epilepsy was induced in male rats by a single systemic injection of lithium and pilocarpine. In two separate experiments, each 6 mo. in duration, the proportion of the population that displayed an overt motor seizure (head nodding, rearing, and forelimb clonus) within 10 min. each day after delivery of food pellets (despite food provided ad libitum) was recorded. Cumulative records for the numbers of rats in each population that displayed overt seizure for the first time during the observation period were plotted as a function of time. The occurrence of the saturated (approaching 100%) asymptote at about five months was interpreted to indicate that brief (10 min.) sampling over the 144 successive days that would compose a single 24-hr. period could serve as an estimate of the average probability of an overt seizure during an average 24-hr. period. If this assumption is correct, then these rats would have displayed about one overt seizure per day.

Animals↗
PubMed2001

Geophysical variables and behavior: XCII. Experimental elicitation of the experience of a sentient being by right hemispheric, weak magnetic fields: interaction with temporal lobe sensitivity.

We tested the hypothesis that proportionally more people with above average numbers of complex partial epileptic-like experiences before the experiment would report a proximal presence during applications of a weak (1 microTesla), frequency-modulated magnetic field over the right hemisphere. Each of 16 subjects sat in a darkened, quiet room and was exposed for 20 min. to complex fields, applied through a helmet, either along the right hemisphere or across both hemispheres. None of the 8 subjects with below average scores reported a presence during the applications of the magnetic fields while 75% and 60% of the 8 subjects with above average scores reported a presence during right hemispheric and bilateral stimulation, respectively.

Adult↗
PubMed2001

Geophysical variables and behavior: CIII. Days with sudden infant deaths and cardiac arrhythmias in adults share a factor with PC1 geomagnetic pulsations: implications for pursuing mechanism.

If geomagnetic-mediated stimuli trigger many sudden infant deaths, then the days in which they and hospital admissions for cardiac arrhythmias for adults occur should share a similar source of variance. Factor analyses of the days in which a sudden infant death occurred in Ontario or adults were admitted for one of eight categories of cardiac crisis in the Sudbury (Ontario) Region for the year 1984 supported the hypothesis. This factor, with which infant deaths and adult cardiac arrhythmias each shared about 40% of their variance, also shared about 40% of the variance with a factor with which about 35% of the variance in daily occurrence of geomagnetic pulsations (0.2 Hz to 5 Hz) was associated. These results are consistent with the important role of geomagnetic variables in the occurrence of transient electrical anomalies in brain function rather than cardiac blood flow.

Adult↗
PubMed2001

Geophysical variables and behavior: CIV. Power-frequency magnetic field transients (5 microtesla) and reports of haunt experiences within an electronically dense house.

Magnetic field measurements for power frequencies were measured continuously over two 24-hr. periods for a small house in which two adults who exhibited above normal occurrences of complex partial epileptic-like experiences had reported "waves of fear", tactile sensations, nightmares, apparitions, and a sensed presence. The experiences occurred within an area in which irregular amplitude modulations between 1 microT and 5 microT (50 mG) from 60-Hz sources, with durations of a few seconds to several tens of seconds, were measured. This case suggests that transient, complex temporal patterns of power-frequency magnetic fields generated by less than optimal grounding in dwellings and telluric currents may be sufficient to evoke experiences in the brains of sensitive individuals. Cultural labels, applied by the experients, then affect the explanations and expectancies for these experiences.

Behavior↗
PubMed2001

Geophysical variables and behavior: XCV. Annual January rainfall may modulate the incidence of luminous phenomena within the San Francisco Basin.

The role of precipitation as a modulator of processes that influence the numbers of reports of anomalous luminous phenomena was investigated within the San Francisco Basin for the years 1950 through 1969. More than 50% of the variance in the numbers of these reports was accommodated by the amount of rainfall during the months of January. The relationship was strongest for events within 100 km of the city. Years in which January rainfall exceeded 8.5 in. and the numbers of earthquakes within the basin increased were associated with the largest numbers of general reports within 400 km from the city, particularly if the previous year had been drier and displayed less seismic activity. Application of the equation to years 1970 through 1995 predicted that above average (z score > 1.5) numbers of luminous displays should have occurred during the years 1973, 1993, and 1995. The results support the corollary of the tectonic strain theory that fluid injection or hydrological loads, natural or man-made, can affect the processes of tectonic strain which facilitate the creation of unusual luminous phenomena.

Electromagnetic Fields↗
PubMed2001

Geophysical variables and behavior: XCVI. "Experiences" attributed to Christ and Mary at Marmora, Ontario, Canada may have been consequences of environmental electromagnetic stimulation: implications for religious movements.

Since the year 1992 individuals and groups of people have reported religious experiences near Marmora, Ontario, Canada. The experiences, attributed to Christ or Mary, have occurred near the top of a hill adjacent to an open pit magnetite mine that has been accumulating about 15 million gallons of water per month for more than a decade. During the period between 1992 and 1997 epicentres for local seismic events moved significantly closer to this site. Most of the messages attributed to spiritual beings by "sensitive" individuals occurred one or two days after increased global geomagnetic activity. We suggest that conditions produced by local geophysical and geological properties created the odd lights and induced physiological changes within the thousands of people who visited the area. Direct measurements indicated that weak (0.1 microTesla to 1 microTesla) complex magnetic fields, the temporal patterns of which were similar to the experimental fields we have employed to evoke the sensed presence and altered states within the laboratory, may have been generated within the area.

Catholicism↗
PubMed2001

Postnatal anoxia from CO2 for one minute produces sex-specific changes in contextual fear conditioning in adult rats.

In a split-litter design, equal numbers of male and female rats were exposed either to carbon dioxide for 1 min, or to the control condition on either postnatal Days 9-10 or 17-18. At 120 days of age half the numbers of rats in each condition were given subclinical dosages of lithium (1.5 mEq/kg) and pilocarpine (15 mg/kg) or saline. 40 days later all rats were tested in a conditioned fear paradigm. A four-way analysis of variance as a function of the variables anoxia, age at the time of anoxia sex, and subclinical seizure induction indicated a significant interaction between sex and anoxic history. Post hoc analysis showed that performance of male rats exposed to the anoxic condition did not differ from normal or anoxic female rats. The results suggest that only 1 min. of preweaning anoxia may produce permanent changes in contextual fear conditioning for male but not female rats.

Animals↗
PubMed2001

Normalization of spatial learning despite brain damage in rats receiving ketamine after seizure-induction: evidence for the neuromatrix.

The concept of the neuromatrix assumes that all behaviours are associated with complex spatiotemporal electromagnetic fields within the brain. The same complex magnetic field can be supported potentially by different mosaics of neuronal associations and result in the same behaviours. In the present study the accuracy of long-term and short-term spatial memory for rats that had been treated with 100 mg/kg of ketamine immediately after the induction of seizures by lithium and pilocarpine did not differ from normal rats despite the conspicuous multifocal neuronal loss. A 30-min. delay of treatment with ketamine resulted in significant memory impairment. Whereas deficits in short-term memory were significantly correlated with cell loss within the CA field of the hippocampus, deficits in long-term memory were related to cell loss within specific thalamic-amygdaloid structures. Implications for the concept of the neuromatrix, if valid, are discussed.

Analgesics↗
PubMed2001

Geophysical variables and behavior: XC. What people consider strange: change in proportions of reports of Fortean phenomena over time.

The proportions of 3,667 reports classified as unusual or odd events within eight major categories for four contiguous blocks of time between 1770 and 1970 were compared for disconcordance. The major source of the disconcordance (phi = .52) of reports between the major categories and time was due to the decrease in the numbers of reports of falls of ice, rocks, and animals but increased numbers of reports of odd luminosities, labelled as unidentified flying objects, after the mid 1930s. One hypothesis to explain this result is that cultural changes in attributions for causes of natural phenomena may affect their designation as strange rather than mundane.

Attitude↗
PubMed2001

Effects of permanent residence with foster mothers and new siblings upon numbers of mast cells within the thalamus of preweaned rats.

In a split-litter, cross-fostered design, the numbers of mast cells per 10 micrometer sections within the thalamic boundaries in rats that had been reared by 8 natural or 8 foster mothers were counted 5 days and 10 days after the transfer had occurred on postnatal Day 10. The rats from 4 litters with the highest numbers of thalamic mast cells exhibited marked reductions in these numbers when fostered by mothers of the 4 litters with the fewest numbers of thalamic mast cells. The reverse influence was not observed. These results suggest that adaptation to changing maternal environments for rats with congenitally elevated numbers of mast cells may increase the risk of degranulation and transient anomalies within cerebral vasculature or the blood-brain barrier.

Adaptation, Psychological↗
PubMed2001

Weight gain in post-seized rats is facilitated by adding aspirin, glucose, or glucose-taurine-acetaminophen to food mush.

Adult male rats were seized with lithium and pilocarpine and administered acepromazine to facilitate survival. After four days (1) 8 mg of acetylsalicylic acid (aspirin), (2) 100 mg taurine-15 mg acetaminophen (Tylenol)-40 mg glucose, (3) 40 mg glucose, or (4) water was added to the food mush daily for 30 days. A fifth group served as non-seized controls. Within one week all pharmacological treatments promoted more weight recovery than food mush only. The rats receiving aspirin (equivalent to 3 tablets/day for humans) showed the greatest early recovery. After 15 days of treatment the pharmacologically treated seized rats had returned to baseline weight and did not differ from normals whereas seized rats given only food mush had not. We suggest inhibiting prostaglandins by anti-inflammatory compounds or stimulating the GABA shunt pathway through enhanced dietary glucose to accelerate weight gain following the significant loss that accompanies brain injury.

Acepromazine↗
PubMed2001

Complex partial epileptic-like experiences in university students and practitioners of Dharmakaya in Thailand: comparison with Canadian university students.

We tested the hypothesis that individuals who frequently practice meditation within another culture whose assumptions explicitly endorse this practice should exhibit more frequent and varied experience associated with complex partial epilepsy (without the seizures) as inferred by the Personal Philosophy Inventory and Roberts' Questionnaire for the Epileptic Spectrum Disorder. 80 practitioners of Dharma Meditation and 24 university students in Thailand were compared with 76 students from first-year courses in psychology in a Canadian university. Although there were large significant differences for some items and clusters of items expected as a result of cultural differences, there were no statistically significant differences between the two populations for the proportions of complex partial epileptic-like experiences or their frequency of occurrence. There were no strong or consistent correlations between the history of meditation within the sample who practiced Dharma meditation and these experiences. These results suggest complex partial epileptic-like experiences may be a normal feature of the human species.

Adult↗