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Biomedical subjects

G S Wasserman

Publications and source records attributed to G S Wasserman.

At least 73 records · Page 4Linked to original sources
PubMed1975

Lomotil ingestions in children.

Although the incidence of adverse reactions is relatively low in adults, Lomotil may result in serious toxicity in children. Early effects are often due to the atropine present in the compound, while the narcotic-like actions of diphenoxylate HCI tend to occur later. Respiratory depression is the most threatening reaction and should be treated with naloxone.

Atropine↗
PubMed1975

Limulus psychophysics: dark adaptation in the ventral eye.

Sudden illumination applied to Limulus produces an unconditioned downward tail movement which is under stimulus control and can be used to measure psychophysical thresholds. The method of constant stimuli was used to measure the behavioral dark-adaptation function mediated by the ventral eye of Limulus. The resulting function has two phases, each of which is rectified when log threshold is made a function of long time in the dark. Under the conditions of the present experiment, the transition between the two phases occurred at 6 min. This psychophysical dark-adaptation function has the same form as an electrophysiologic dark-adaptation function obtained by Fein and DeVoe (using the ventral eye receptor potential as the response). In more complex visual systems such two-phase, dark-adaptation functions would usually be interpreted in terms of screening pigment movements or changes in the neural contributions of different receptor classes, but neither interpretation is appropriate for the ventral eye of Limulus.

Animals↗
PubMed1974

Illusory correlation of brightness enhancement and transients in the nervous system.

Short light flashes can appear brighter than longer flashes. This brightness enhancement has often been attributed to neural transients occurring shortly after stimulus onset. This attribution assumes an equivalence between the totality of the response to a stimulus of a given duration and the instantaneous response at a given time after stimulus onset. Recordings from Limulus photoreceptors indicate that this attribution is an example of illusory correlation.

Animals↗
PubMedDate not supplied

Adaptation-dependent differences in electroretinographic latency patterns in uniform and variegated horseshoe crabs.

The carapaces of horseshoe crabs (Limulus polyphemus) differ. Some individuals have uniform carapaces and clear eyes while others have variegated carapaces and dark eyes. These differences have been reported to be correlated with latency differences in the electroretinogram (ERG) of the lateral eye. Such a result might have had a neural basis in the mechanisms underlying visual transduction but it could also have reflected a visual screening pigment difference. A direct experiment was therefore designed to choose between these two hypotheses by varying the relative state of adaptation. The results were as follows. In uniform animals, dark adaptation had the kind of effect seen in single photoreceptor cells - latencies were longer in dark-adapted eyes and latencies were also longer for dim flashes. However, variegated animals showed a significant adaptation interaction: in light adaptation, dimmer flashes produced the usual effect, namely a longer ERG latency, while in dark adaptation, latencies were close to equilatent, being within experimental error of each other for both flash energies. These data make it unlikely that the photoreceptor transduction mechanism is the locus of the visual differences between the two types of animals. Instead, they are consistent with an interaction of screening pigment effects with photoreceptor transduction effects.

Adaptation, Physiological↗