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Biomedical subjects

G P Frommer

Publications and source records attributed to G P Frommer.

18 recordsLinked to original sources
PubMed1986

Mood change preceding epileptic seizures.

Mood ratings were obtained for at least 56 days from 27 patients with diverse forms of epilepsy, 13 of whom suffered at least one seizure over the course of the study. For these 13 patients, mean ratings of mood on eight of the 10 scales showed a decline on the day(s) preceding the seizure and an increase after the seizure. Data from six patients accounted for most of the decline. Decline was most prominent on the Depression, Anxiety, Freedom, and Anger Scales. One patient's mood ratings rose significantly before seizures. Comments recorded before the seizures confirmed the decline in mood preceding seizures and showed an increase in negative life events for the patients whose mood declined before seizures. The relations of life events and mood to seizures apparently did not depend on each other.

Emotions↗
PubMed1985

Disruption of tactile discrimination in rats by bilateral stimulation of midbrain lemniscal pathways.

Bilateral stimulation in the midbrain medial lemniscus disrupted tactile discrimination in four of nine rats. Single conditioning shocks in the midbrain of these animals attenuated by more than 80% the somatosensory cortical evoked responses elicited by test shocks to the contralateral forepaw. Midbrain stimulation did not selectively disrupt discrimination in the remaining five rats, and midbrain conditioning shocks attenuated the cortical test response by less than 80% on at least one side. The four rats that showed disrupted discrimination and bilaterally strong attenuation of cortical responses also had both midbrain electrodes in or next to the medial lemniscus. The five rats that did not show these effects had at least one midbrain electrode away from that structure.

Animals↗
PubMed1984

Deficits in visual discrimination performance following neglect-producing unilateral lateral hypothalamic lesions in the albino rat.

Adult male albino rats were trained with water reinforcement on a lateralized visual discrimination task. For six rats the correct head turn--nose poke response was to the same side as the discriminative stimulus (Turn Towards group). For six others the correct response was to the side opposite from the discriminative stimulus (Turn Away group). Immediately after a rat had mastered its task, a unilateral electrolytic lesion was made under ether anesthesia through a stainless steel electrode previously implanted in the lateral hypothalamus (LH). Discrimination training continued until the rat's performance returned to criterion. The lesions produced contralateral neglect as demonstrated by deficits in turning and orientation contralateral to the lesion. The lesions also disrupted all measures of discrimination performance (% correct, latency, and duration of observing response) for trials on which responses contralateral to the lesion were correct, regardless of whether the discriminative stimulus was also contralateral (Turn Towards group) or was ipsilateral (Turn Away group). These data are interpreted as showing that contralateral neglect following LH lesions is associated with a deficit in initiating instrumental responses contralateral to the lesion. They also confirm previous results from a similar task using tactile discriminative stimuli.

Animals↗
PubMed1977

Somatosensory function and cortical unit activity in cats with only dorsal column fibers.

Cats received lesions that transected the entire thoracic cord except for partial sparing of the dorsal columns. The cats were required to discriminate the side on which they were touched, the size of simultaneously presented discs, or the direction their fur was stroked to obtain food reward. All cats found by anatomical and/or electrophysiological criteria to have any functional continuity in the dorsal columns were able to master the first of these tasks; some responded above chance on the second. Performance was at chance on blank trials, and cats with complete cord transection failed to discriminate. Lesioned cats did not orient or otherwise react to any nonrewarded stimulus below the level of the lesion. A total of 532 units were recorded under light barbiturate anesthesia from the hind paw projection near the tip of the ansate sulcus in these and other similarly prepared cats. Three-fourths of the units found before and acutely after the cord lesions were made were driven by hind limb stimulation. Only 27% of the units recorded 10 or more days afterwards could be driven. Of these driven units, 15 (38%) responded to foreleg stimulation, 13 exclusively so. No such units were found in intact or acutely lesioned cats.

Animals↗
PubMed1975

Hypothalamic influences on sensory reinforcement.

Rats were tested in a darkened chamber containing two levers, one of which turned on a dim light when depressed. Rats receiving non-contingent electrical stimulation of the lateral hypothalamus made many more lever presses than did unstimulated controls and made more presses on the light producing lever than on the inactive one. Pretests had shown that the electrical stimulation elicited consummatory behavior in the presence of appropriate goal objects. Dynamic hyperphagic rats maintained on a restricted diet made more total responses early in testing than did their controls which also received the same restricted diet. They also preferred the light producing lever, but not reliably more than did their controls. Static hyperphagic rats made fewer total responses than did their controls, both groups receiving food ad lib. Neither group showed any preference between the two levers.

Animals↗