A neurophysiologic model for aggressive behavior in the cat

A neurophysiologic model for aggessive behavior in the cat is proposed. Stimulus-bound and seizure-bound aggression was evaluated in relation to limbic and basal ganglia induced seizures (after-discharges). Electrically induced limbic and basal ganglia afterdischarges were used because they are known to implicate septohypothalamic sites from which aggression can be elicited by direct stimulation. The occurrence of behavioral aggression is correlated with the discharge characteristics of a single discharging system and with two interacting discharging systems. Aggression is composed of autonomic and somato-motor components which poses relatively low and high thresholds, respectively, for their activation. Aggression occurring during a combined septum and amygdala discharge was more intense and prolonged than with a septum discharge alone. Participation of a slow frequency discharging basal ganglia system activated seizurebound aggression in an otherwise nonaggressive limbic seizure. The limbic and basal ganglia stimulations and after-discharges lowered the excitability threshold of the aggression system and made it more vulnerable to being activated by external stimuli, such as visual and auditory stimuli. These observations are reminiscent of patients with aggressive behavior associated with psychomotor seizures.     

Limbic system seizures and aggressive behavior (superkindling effects)

Integrative Psychological and Behavioral Science - This study was done to further analyze the neural mechanisms underlying aggressive behavior associated with psychomotor or temporal lobe seizures....     

The development of children's action memory: When do actions speak louder than words?

Summary Although acting consistently has been found to improve memory, the reasons for this are unclear. In this investigation, we tested whether acting improves recall by integrating separate elements within an action into an organized whole and whether this process may be strategic. First graders, fourth graders, and college-aged adults listened to, acted out, or watched the performance of action-object phrases and then verbally reported or enacted the phrases. Phrases composed of transitive verbs were expected to be integrated more by action than phrases composed of intransitive verbs, and consequently recalled better, especially by the younger children. Recall increased between first and fourth grades, suggesting that some aspects of action memory may be strategic; however, there was no evidence that acting improves recall by means of integration. The pattern of results suggested that the nature of an action's outcome may contribute to the enactment effect.     

A broadband digitizing rat detector: Simultaneous recording from all sound frequencies in the range of rat ultrasonic vocalizations

A system is described that digitizes rodent vocalizations after the signals have passed through a spectrum analyzer. The system’s capacity to record simultaneously from all frequencies in a range selected by the experimenter is demonstrated. In the graphic display, both single and simultaneous multiple vocalizations of rats ranging freely in large experimental rooms are presented. The capacity of this system to record simultaneous vocalizations in a form that permits rapid analysis of many of the parameters of the signals is especially useful in the analysis of rodent social behavior.     

Hypersexuality and limbic system seizures

Hypersexual behavior was induced in adult male cats by repeatedly evoked limbic system seizures. Accentuation of Dopaminergic activity with drugs was used to facilitate development of the seizure induced hypersexuality. Hypersexuality consisted of biting knap of neck, mounting, thrusting and coital intromission. The gradual development and eventual disappearance of hypersexuality was correlated with the progressive prolongation of the seizures in their evolution. There are three stages of seizure evolution in relation to sexuality. First stage-normal sexuality, intermediate stage-hypersexuality and late stage-hyposexuality. A theoretical “hypersexual growth and decay curve” was constructed in relation to the evolution of limbic seizure durations in the intermediate stage. It was suggested that the observed hypersexuality was related to the early discharge activation of hypothalamic, preoptic and basal ganglia neurohumeral facilitatory mechanisms for sexuality, and the late effects were related to discharge activation of brain stem serotonergic inhibitory mechanisms. The discussion attempts also to use these experimental findings to explain clinically observed hyposexuality and hypersexuality. It was suggested that either hypersexuality or hyposexuality may be associated with psychomotor seizures and that the predominating sexual state at a given moment is dependent upon the evolutionary stage of the seizure at that moment. Consequently, psychomotor seizures with associated hypersexuality should not be considered a clinical anachronism. In fact, these observations support the impression that rape may be a manifestation of a psychomotor seizure.