Aggressive behavior inhibition by serotonin and quipazine injected into the amygdala in the rat

The effects on aggressive behavior, open-field activity, and pain threshold of bilateral microinjections of serotonin (20 micrograms) and quipazine (20 micrograms), the direct serotonergic receptor agonist, into the cortico-medial amygdala were investigated in Wistar rats. Both drugs significantly prolonged the attack latency in isolated killer rats (predatory aggression model), and suppressed the incidence of aggressive postures/attacks in shock-induced fighting test (affective aggression). The only difference in the open-field behavior was the lower number of central square entries in drug-treated compared to saline-injected rats. None of the substances produced any significant change in jump threshold. It is concluded that stimulation of serotonin receptors within the amygdala produces inhibition of affective and muricidal behavior in isolated rats. The effect does not seem to be dependent on changes in general activity and pain sensitivity.     

The psychological cost of waiting

The study of any problem involving waiting situations invariably assumes that people dislike having to wait. The analysis of queueing problems usually prescribes that some costs should be associated with the time people spend waiting to be served. These are usually considered to be of an economic nature, though the existence of other costs of a psychological nature is accepted. It is generally accepted that after having to wait for a certain amount of time, anxiety and stress start to build up in an individual, due both to the sense of waste and the uncertainty involved in a waiting situation. This work provides a theoretical basis for analysing this building up process as it occurs during the waiting period. It is proved that, under very general conditions, the resulting psychological stress accumulated during the process is a marginal increasing function of the waiting time, and some strategies to minimise it are developed. The results obtained give theoretical support to the usual assumptions underlying the development of systems to provide “real time” information to people in waiting situations. This is especially important in the operation of public transportation systems. The results also provide theoretical support to the “convex” treatment usually given to the waiting cost function in queueing problems.     

Frequency of neurologic-psychiatric findings in the late phase following minor and medium severe blunt craniocerebral injuries

The authors present a short review of the pertinent literature and report on their own neuropsychiatric findings following internal craniocerebral injuries, at the same time drawing attention to the necessity of psychological examination. Statistical comparisons with the international literature are complicated owing to the different classifications used for craniocerebral injuries.     

Electromagnetic articulography: use of alternating magnetic fields for tracking movements of multiple points inside and outside the vocal tract

The purpose of this paper is to present a new electromagnetic device which uses alternating magnetic fields for tracking movements of multiple points inside and outside the vocal tract. It is biologically safe, noninvasive, it does not interfere with speech movements, allows for multiple recording in the same subject, and for easy collection of large amounts of data. It is especially suitable for evaluation of patients with speech motor impairments.