Light Avoidance Research Articles

Scotophobin A causes several responses in goldfish if the pineal gland is present

Rat scotophobin A increased dark avoidance in goldfish in dark and light avoidance shuttlebox experiments, controlled for general and light cycling-induced swimming activity. A possible site of action for scotophobin was suggested by the reports that dark avoidance was also increased in goldfish by pinealectomy, a treatment which increased shock sensitivity as well. It was found that scotophobin alone decreased the voltage required to induce tail-flip contractures in goldfish. The pineal gland was further implicated in the mode of action of scotophobin when it was found that this peptide suppressed the norepinephrine-induced aggregation of goldfish chromatophores whose state is in part controlled by pineal melatonin. Pinealectomized goldfish became insensitive to the effects of scotophobin upon both light-dark preference and chromatophore aggregation state. These observations strongly suggest that phe piaeal gland is required for the action of scotophobin.

Correlation between estrus and reduced light avoidance in mice

Female CD-1 mice showed reduced light avoidance at estrus compared to nonestrus in two experiments designed to control for possible effects of changes in general activity. Estrous mice were quicker to enter a light chamber from a dark chamber and slower to enter a dark chamber from a light chamber, than nonestrous mice. Also, estrous mice reared up on their hind legs more frequently than nonestrous mice in the light chamber, and there was no difference between estrous and nonestrous mice in motor activity in the dark chamber. These findings, along with previous findings of reduced shock avoidance at estrus, suggest a general decrement in avoidance motivation which may be adaptive to the process of mating and which does not appear to be secondary to a change in activity level.

Effects of subcortical lesions on visual intensity discriminations in rats

The role of several subcortical structures in visual intensity discrimination was examined by comparing the effects of localized lesions on a variety of intensity discriminations. In Experiment 1 light avoidance was unimpaired after lesions of the ventral lateral geniculate nucleus (LGNv), nucleus lateralis posterior (TLP), nucleus posterior of Gurdjian (NPG), dorsal pretectum (PTd), and ventral pretectum (PTv). The LGNv, TLP, NPG and PTv, but not the PTd, groups were impaired on a simultaneous black versus white (BW) discrimination in Experiment 2. None of these groups was impaired on a horizontal versus vertical discrimination (HV). The TLP group showed a transient impairment on a successive light versus dark discrimination, not present with the LGNv and NPG groups (Experiment 3). In Experiment 4 all three groups were impaired on a successive BW discrimination. In Experiment 5 rats with LGNv lesions but not with TLP lesions had elevated relative brightness thresholds. Both groups had normal absolute thresholds. The results are related to the possibility that information about intensity and pattern is coded in separate visual pathways.

Electronic circuit for controlling a shuttle box behavioural experiment

A circuit used to control the conditioning of fish to light avoidance, which is adaptable to other shuttle box applications, is described. Photocell detectors repetitively operate light sources and shock pulses at a rate dependent on the fish's response and pre-set delays between the CS (controlled stimuli).

Light aversion of normal and posterior neodecorticate rats

The light aversion behavior of normal rats and rats with posterior neocortex lesions was examined in a two-choice brightness (card) discrimination task. By varying pretraining procedures, normal rats could be shown to have apparent light preferences, light aversion, or no preferences. Neither normal rats nor lesioned rats showed light avoidance tendencies in tasks in which pretraining biases were removed. The results indicate that the light avoidance tendencies shown by the normal or lesioned rats in free choice tasks are not reflected on card discrimination tasks.

Complementation between mutants of Phycomyces with abnormal phototropism

Fifteen mutants of Phycomyces blakesleeanus with abnormal phototropism (phenotype mad), obtained by mutagenesis with nitrosoguanidine, were tested for genetic complementation using heterokaryons produced by grafting stage I sporangiophores. Five complementation groups were found, defining five genes, designated madA to madE. This grouping of the mutants is completely consistent with the phenotypic classification scheme of Bergman et al. (1973), based on sensory responses of the sporangiophore other than those to light (geotropism and avoidance), and two responses of the mycelium to light. At two points the complementation grouping refines this scheme. The groups A, B and C coincide with the class 1 mad mutants of Bergman et al. which have a high threshold for the photoresponses but show normal geotropism and avoidance. Class 1 can be subdivided further into 1.1 (groups A and B) and 1.2 (group C), depending on whether the mutants do not or do show normal mycelial responses. The groups D and E coincide with class 2 which is defective on the output side of the sporangiophore growth response.

Light avoidance in normal rats and rats with primary visual system lesions

The light-avoidance behavior of normal rats and rats with primary visual system lesions was examined in a differentially illuminated two-choice chamber over 28-58 days. Light avoidance in normal rats was distributed as a J curve, with some rats spending little time in the light and some rats spending up to 12 h each day in the light. Normal rats ate in the dark compartment, hoarded food to the dark, but defecated in the lighted compartment. Enucleation abolished light avoidance and the other behaviors. Neither small nor large posterior neocortex lesions affected light avoidance or other behaviors. Avoidance behavior was also unchanged following superior colliculus lesions and pretectal lesions, but was increased by lateral geniculate lesions, posterior thalamus lesions or combined posterior neocortex and hippocampal lesions, and posterior neocortex and superior colliculus lesions. The results do not support previous suggestions that primary optic-center lesions decrease light avoidance in the rat.

Synthetic scotophobin in goldfish: specificity and effect on learning.

Synthetic rat scotophobin was injected intracranially into common goldfish (Carassius auratus) which were then trained to avoid light or dark. The substance interacts with the learning process in goldfish in an apparently specific way, facilitating the acquisition of dark avoidance, a task homologous with that acquired by rats from which the natural peptide was isolated, while inhibiting acquisition of light avoidance.

Effects of Oxygen Depletion and of Carbon Dioxide Buildup on the Photic Behavior of the Walleye (Stizostedion vitreum vitreum)

In laboratory experiments under overhead white light, walleyes (Stizostedion vitreum vitreum (Mitchill)) displayed a negative phototactic response consistent with field observations and histological features of the walleye eye. The strength of this innate response proved to be largely dependent on the given respiratory situation: during oxygen depletion and during buildup of free carbon dioxide, this response diminished to the point of obliteration, which occurred at levels leaving mobility and equilibrium of the test specimens still intact. Whereas during the course of oxygen depletion a wide indifference zone (little or no change of light behavior) could be observed from saturation (= acclimation) level down to about 4–2 mg/liter, the fish reacted rather sensitively to increase of free carbon dioxide. Starting from acclimation levels of 1.0–2.0 mm Hg CO2, the light avoidance response declined gradually while approaching tensions of 5 mm Hg or more, being completely abandoned at levels above 15 mm Hg. This effect could not be attributed to pH shifts.

The effect of thigmo taxis on negative phototaxis in the earthworm

Negative phototaxic (light avoidance) responses of earthworms were measured under two thigmotaxic (bodily contact) conditions: presence or absence of an alley. As predicted by Smith (1902), the presence of an alley greatly increased the time taken by Ss to move away from a light source. It was concluded that thigmotaxis is a powerful motivational variable in the earthworm.

Occipital ablation and retention of a visual conditioned avoidance response in the rat

Retention of a cooperatively established light contingent avoidance response following bilateral occipital ablation was studied. The two variables of interest, level of preoperative training and duration of postoperative recovery period, had a significant effect upon postoperative retention.

Intraventricular administration of reserpine and its metabolites to conscious cats.

Intraventricular injection of reserpine in conscious cats produced relaxation of the nictitating membrane, miosis with narrowing of the palpebral fissure to a slit, avoidance of light, diarrhoea, anorexia, and tranquillization. Equivalent doses of trimethoxybenzoic acid, reserpic acid or methylreserpate separately or in combination did not produce such effects, indicating that these reserpine metabolites were not involved in these reserpine actions. 5-Hydroxytryptamine alone or in combination with subthreshold doses of reserpine also did not duplicate the effects observed after effective doses of reserpine. The possible central sites of reserpine action are discussed.

The Distribution of Neomysis americana in the Estuary of the Delaware River1

Observations on the planktonic shrimp, Neomysis americana (Smith), in the Delaware River estuary were carried out over a period of two years. It was found that Neomysis was far more abundant in the deep water of the estuary than in the near‐surface or shallow water. Moreover, it was more abundant within the estuary than in the coastal waters at the mouth of Delaware Bay. Measurements of the length of the animal showed increase in size from the ocean toward the river end of the estuary. These features are interpreted in light of the probable circulation of the estuary to show that the animals became older during their “up‐estuary” drift in deep water. Furthermore, they tended to accumulate within the estuary due to their avoidance of the out‐flowing surface waters. A principal source for Neomysis in the coastal waters outside the Bay is thus suggested. During spring and summer, however, reproduction within the Bay contributed to the stock of animals there. The up‐estuary extent of Neomysis was related to the 4‰ isohaline, and the partial exclusion from surface waters was attributed to their avoidance of excessive light.

An investigation of light avoidance as motivation in a perceptual differentiation problem in the cat.

An investigation of light avoidance as motivation in a perceptual differentiation problem in the cat.

The application of light avoidance in a perceptual differentiation problem in the pekin duck.

The application of light avoidance in a perceptual differentiation problem in the pekin duck.

The utilization of light avoidance as motivation in the investigation of perceptual differentiation in the pigeon.

(1955). The Utilization of Light Avoidance as Motivation in the Investigation of Perceptual Differentiation in the Pigeon. The Journal of Genetic Psychology: Vol. 87, No. 2, pp. 293-299.

Environmental Changes in Herring Behaviour: a Theory of Light Avoidance, as Suggested by Echo-Sounding Observations in the North Sea

Environmental Changes in Herring Behaviour: a Theory of Light Avoidance, as Suggested by Echo-Sounding Observations in the North Sea