Motivational variables and the sensitization and habituation of aggression in the convict cichlid (Cichlasoma nigrofasciatum).

Four experiments using territorial Convict Cichlids investigated motivational factors involved in the incremental and decremental processes associated with aggression resulting from exposure to conspecifics intruded into the territory. The first three experiments varied some single aspect of the experimental situation (temperature, distance from the nest or size of the intruder). The fourth experiment combined those factors which resulted in faster habituation (small intruder, far from the nest, in cool water) and compared the response to factors which resulted in slower habituation or an increase in response rate (large intruder, close to the nest in warm water). While a combination of higher intensity stimuli did result in slower habituation than the combination of lower intensity stimuli, response rate was not a simple algebraic summation of the factors. Results are discussed in relation to multi-factor theory of habituation and the nature of "drive".

Morphine withdrawal induced behavior in the Syrian hamster (Mesocricetus auratus).

The effects of morphine withdrawal on a number of behaviors was assessed using a design varying sex, amount of morphine implanted, degree of dependence at the time of testing and amount of morphine antagonist injected. Increases in two types of agonistic behavior were seen and may be related to the aversive interoceptive stimuli associated with withdrawal. Furthermore, correlations for males were found between agonistic behavior and activity, wet shakes, digging and vocalization. Agonistic behavior was correlated only with activity in females.

The effects of pargyline, scopolamine, and imipramine on territorial aggression in the convict cichlid (Cichlasoma nigrofasciatum).

Scopolamine, pargyline, and imipramine reduce territorial aggression in the convict cichlid. Imipramine is effective at much lower doses than either scopolamine or pargyline. None of the drugs affected activity or predation/feeding, indicating that the observed drug effects are relatively specific.

Alcohol, habituation and the patterning of aggressive responses in a cichlid fish.

Territorial cichlids were presented for 30 min with a conspecific male intruder (contained in a clear glass tube). Eight hr prior, 2 groups were administered alcohol (0.15 or 0.30 percent in the aquaria water). A third group served as a control. Three responses were recorded to allow analysis of topographic changes in behavior as well as changes in absolute levels. During the habituation phase, the normal group showed a sequence of long displays, followed by shorter ones as the frequency of attacks increased. The occurrence of threat which gradually gives way to attack is characteristic of the agonistic behavior of this species. In contrast to the controls, the 0.15 percent group was hyperaggressive, while the 0.30 percent group was hypoaggressive. Furthermore, the patterning of responses were abnormal. The 0.15 percent group gave abbreviated threats and more attacks (interpreted as a tendency to attack without warning); whereas, the 0.30 percent group gave many long threat displays, but few attacks. A stimulus specificity test provided strong evidence that the waning found during the initial phase was habituation.

Differentiation by morphine of two types of aggressive behaviour in the convict cichlid (Cichlasoma nigrofasciatum).

Morphie sulfate (5 mg/l and 10 mg/l) significantly decreased the amount of territorial aggression in the convict cichlid (Cichlasoma nigrofasciatum). The same doses had no effect on predatory aggression (ingestion of brine shrimp). The data suggest that previously demonstrated morphine receptor in the fish has functional properties.

Retrograde amnesia produced by hippocampal spreading depression.

Injection of potassium chloride into the hippocampus produces a disruption of electrical activity; a concomitant of this disruption is a deficit in retention of conditioned suppression learned 24 hours before injection.