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Biomedical subjects

C A Hawkins

Publications and source records attributed to C A Hawkins.

23 records · Page 2Linked to original sources
PubMed1985

Antiepileptic and antiamnesic effect of carbamazepine in experimental limbic epilepsy.

Carbamazepine (20 mg/kg, 40 mg/kg or 60 mg/kg) given three times a day, has been demonstrated to have a significant anti-epileptic effect in rats with chronic limbic epilepsy induced by injecting tetanus toxin bilaterally into their hippocampi. This effect involved a reduction in the maximum number of fits occurring on one day, and with the highest dose, a significant reduction in the total number of fits. In a pilot experiment in which continuous EEG records were obtained throughout the syndrome, it appeared that the effect of carbamazepine was to reduce the proportion of EEG seizure discharges which lead to overt motor fits. With the higher drug dose plasma levels of carbamazepine were maintained around 2 micrograms/ml. This experimental epilepsy produces enduring deficits in the rats' memories for a light-discrimination task in a Y-maze learned before induction of epilepsy (8 weeks after initial learning). If the rats are dosed with carbamazepine during their epilepsy this memory deficit is abolished.

Amnesia↗
PubMedDate not supplied

Disruption of family rituals as a mediator of the relationship between parental drinking and adult adjustment in offspring.

This study investigated whether disruption of family-of-origin rituals and routines would mediate the relationship between family history of parental problem drinking (FH+, FH-) and two outcomes in adult offspring: adult children of alcoholics (ACOA) personality attributes and drinking problems. The self-reports of 143 students and 129 outpatients indicated that disruption of family routines and rituals mediated the relationship between family history status and both ACOA traits and problem drinking. These results suggest that the mediating effect of family-of-origin rituals and daily routines may explain some of the heterogeneity in adult outcomes of offspring from FH+ families, in both student and clinical samples.

Activities of Daily Living↗
PubMedDate not supplied

Limbic epilepsy induced by tetanus toxin: a longitudinal electroencephalographic study.

An epileptiform syndrome was induced in rats by injection of tetanus toxin (approximately 10 mouse LD50) unilaterally into the hippocampus. Continuous EEG records were obtained from implanted hippocampal electrodes for periods of 4-7 weeks in 14 rats. In a pilot study of two of these rats, three more recording electrodes were placed in other brain areas. Six of the rats (including the latter two) were simultaneously filmed using time-lapse videorecording, and the relationships between EEG events and overt motor fits were assessed using a split-screen video monitoring system. Characteristic peaks and troughs in the numbers of overt fits occurring each day were noted in all the rats that were filmed, and less marked peaks occurred in the numbers of hippocampal seizure discharges. At the start of the syndrome, seizure discharges occurred without accompanying fits; then overt fits occurred with some of the discharges; later the animals stopped having fits but seizure discharges continued to occur alone for several weeks. Fits only occurred with longer seizure discharges (more than approximately 30 s), but not all longer seizures were associated with fits. Whether or not a hippocampal seizure discharge leads to a motor fit appears to depend not on the nature of the electrical activity in the hippocampus but probably on the properties of areas, such as the cingulate gyrus, to which the seizure activity may spread. Large epileptiform spikes occurred throughout the syndrome, and their frequency was often increased for some minutes after a seizure discharge. While there was an overall correlation between the number of fits and the number of seizure discharges occurring during the entire syndrome, within relatively brief periods this relation was not consistent. The occurrence of motor fits was often associated with a decrease in seizure discharge frequency. In the four rats with bilateral electrodes, some independent EEG activity was observed in the uninjected hippocampus.

Animals↗
PubMedDate not supplied

Effect of experimental limbic epilepsy on the estrus cycle and reproductive success in rats.

Epilepsy was induced in female rats by the injection of tetanus toxin (5 mouse LD50) unilaterally into the ventral hippocampus under anesthesia. During the 2-4 weeks that the rats exhibited intermittent spontaneous convulsions, daily vaginal smear tests showed that their estrous cycle was interrupted. In control rats such interruption only occurred for just a few days after the operation. Investigation of mating behavior, on the first night of proestrus, which occurred after 7 weeks from the operation, showed that there were fewer mounts, intromissions or ejaculations from the males, which were caged with previously epileptic animals. These females produced slightly smaller litters than their controls and there was a marked failure of their young to thrive in comparison with those of the control females. This failure appeared to be related to relatively high "stress" levels in the general laboratory environment. The impairment of reproductive success only lasted about 3 months after the original induction of epilepsy since subsequent litters to the same animals thrived normally.

Animals↗