Effects of exposure to an estrous female on forebrain monoaminergic neurotransmission in the non-copulating male rat

Regional changes in the rate of brain monoamine synthesis were monitored in male rats exposed to, but prevented from physical contact with, an estrous or an ovariectomized female. The in vivo rate of tyrosine and tryptophan hydroxylase activities were estimated by measuring the accumulation of DOPA and 5-HTP following inhibition of cerebral aromatic l-amino acid decarboxylase by means of 3-hydroxybenzylhydrazine (NSD-1015) treatment (100 mg/kg i.p.) 5 min upon NSD-1015 treatment, the males were exposed to an intact estrous female or an ovariectomized female for 20 min before decapitation and brain dissections. Exposure to an estrous female produced an increased rate of tyrosine and tryptophan hydroxylase activity in the medial prefrontal cortex, the dorso-lateral neostriatum and in the ventral neostriatum, in comparison with home-cage controls. By the same comparison, exposure to an ovariectomized female resulted in an increased rate of tyrosine hydroxylase activity in the medial prefrontal cortex, byt not in the neostriatal areas, whereas tryptophan hydroxylase activity was unaffected. Finally, exposure to the empty test cage, with no stimulus females present, did not produce any statistically significant changes in the rate of tyrosine or tryptophan hydroxylase activity in any of the brain areas sampled. Taken together with recent findings from this laboratory, the present results demonstrate that the level of sexual motivation brought about by the olfactory, auditory and/or visual stimulation of a receptive female is associated with an increased demand on catecholamine and 5-hydroxytryptamine synthesis in the limbic forebrain of the male rat. The finding that the presence of an unestrous female produced an enhanced demand on tyrosine hydroxylase activity in the medial prefrontal neocortex demonstrates that the sexual incentive provided by the estrous female may not be the only factor responsible for all the effects observed in the present study. In fact, there is a distinct possibility that the intense challenge produced by sexually significant stimuli is but an endpoint, and that the changes found in forebrain monoamine synthesis is a reflection of an environmental challenge not necessarily specifically linked to the sexual behavior.     

Effects of 8-OH-DPAT on motor activity in the rat

The administration of 8-OH-DPAT to rats produced a dose-dependent suppression of spontaneous locomotor activity in an open field arena. 8-OH-DPAT was administered in the dose range 12.5-1,600 micrograms.kg-1 SC. Vertical activity ("rearing") was more sensitive to the treatment than horizontal activity ("locomotion"), both in terms of potency and efficacy. The activity along the walls of the open field arena ("peripheral activity") was increased, and the rearing activity was decreased, relative to total horizontal activity and total activity, respectively. There were no effects by 8-OH-DPAT on treadmill locomotion. The rectal temperature was decreased by 8-OH-DPAT administration, not only in animals tested in the open field, but also in animals with an increased body temperature, produced by treadmill locomotion.     

Traumatic experiences and posttraumatic stress reactions in children and their parents from Kurdistan and Sweden

This study was conducted to assess trauma scores and posttraumatic stress symptoms among Kurdistanian refugee children and their parents in Sweden and a comparable group of Swedish children and their parents. Comparative Kurdistanian and Swedish samples composed of 32 children each and their parents were interviewed by means of a specially devised trauma instrument (HUTQ-C), to identify traumatic events and to measure trauma scores, and with (PTSS-C) and (HTQ) to diagnose posttraumatic stress syndrome (PTSD) among children and adults, respectively. Although Kurdistanian parents reported considerably more traumatic events than Swedish parents, children in both samples showed more similarities than differences, both with regard to types and levels of traumatic events. Kurdistanian parents showed higher PTSD frequencies than Swedish parents. However, these differences proved to be significant with regard to both the mother's and the father's lifetime and current PTSD symptom scores. Kurdistanian parents have experienced more war traumas and differ with regard to trauma exposure and its consequences when compared with Swedish parents. Children from the two samples showed more similarities than differences with regard to reported trauma and PTSD-related symptoms. These results underline the significance of child-specific factors in trauma and PTSD.