Anatomical and developmental aspects of leaf galls induced by Schizomyia macrocapillata Maia (Diptera: Cecidomyiidae) on Bauhinia brevipes Vogel (Fabaceae)

Samples of healthy leaves and galls induced by Schizomyia macrocapillata Maia on Bauhinia brevipes Vogel were submitted to routine techniques to investigate gall anatomy and development. Pouch galls are induced on the abaxial surface of unfolded immature leaves, and become spheroid with long reddish hairs covering their external surface. Galls occur isolated or coalesce when in larger numbers. Gall development was divided into six phases: 1) initiation; 2) tissue re-arrangement; 3) tissue differentiation; 4) maturation; 5) growth phase; and 6) dehiscence. This last phase corresponds to gall senescence, which takes place just after the larva exits the chamber to pupate. An important developmental phase of tissue reorientation was recorded after the initiation phase. The presence of hyphae close to the covering layer characterizes this gall as an ambrosia gall and the feeding mode of the gall migde is discussed. Few hyphae were found during the first developmental phases and fungi may play an important role during gall morphogenesis. Neoformed trichomes may provide not only photoprotection but also protection against natural enemies and water loss. The neoformation of phloematic bundles suggests host manipulation and indicates the establishment of a deviating sink.

Maternal aggression in Wistar rats: effect of 5-HT2A/2C receptor agonist and antagonist microinjected into the dorsal periaqueductal gray matter and medial septum

The objective of the present study was to assess the role of the 5-HT2A/2C receptor at two specific brain sites, i.e., the dorsal periaqueductal gray matter (DPAG) and the medial septal (MS) area, in maternal aggressive behavior after the microinjection of either a 5-HT2A/2C receptor agonist or antagonist. Female Wistar rats were microinjected on the 7th postpartum day with the selective agonist alpha-methyl-5-hydroxytryptamine maleate (5-HT2A/2C) or the antagonist 5-HT2A/2C, ketanserin. The agonist was injected into the DPAG at 0.2 (N = 9), 0.5 (N = 10), and 1.0 µg/0.2 µl (N = 9), and the antagonist was injected at 1.0 µg/0.2 µl (N = 9). The agonist was injected into the medial septal area (MS) at 0.2 (N = 9), 0.5 (N = 7), and 1.0 µg/0.2 µl (N = 6) and the antagonist was injected at 1.0 µg/0.2 µl (N = 5). For the control, saline was injected into the DPAG (N = 7) and the MS (N = 12). Both areas are related to aggressive behavior and contain a high density of 5-HT receptors. Non-aggressive behaviors such as horizontal locomotion (walking) and social investigation and aggressive behaviors such as lateral threat (aggressive posture), attacks (frontal and lateral), and biting the intruder were analyzed when a male intruder was placed into the female resident's cage. For each brain area studied, the frequency of the behaviors was compared among the various treatments by analysis of variance. The results showed a decrease in maternal aggressive behavior (number of bites directed at the intruder) after microinjection of the agonist at 0.2 and 1.0 µg/0.2 µl (1.6 ± 0.7 and 0.9 ± 0.3) into the DPAG compared to the saline group (5.5 ± 1.1). There was no dose-response relationship with the agonist. The present findings suggest that the 5-HT2A/2C receptor agonist has an inhibitory effect on maternal aggressive behavior when microinjected into the DPAG and no effect when microinjected into the MS. Ketanserin (1.0 µg/0.2 µl) decreased locomotion when microinjected into the DPAG and MS, but did not affect aggressive behavior. We interpret these findings as evidence for a specific role of 5-HT2A/2C receptors in the DPAG in the inhibition of female aggressive behavior, dissociated from those on motor activity.

Motor behavioral abnormalities and histopathological findings of Wistar rats inoculated with HTLV-1-infected MT2 cells

The objective of the present study was to describe motor behavioral changes in association with histopathological and hematological findings in Wistar rats inoculated intravenously with human T-cell lymphotropic virus type 1 (HTLV-1)-infected MT2 cells. Twenty-five 4-month-old male rats were inoculated with HTLV-1-infected MT2 cells and 13 control rats were inoculated with normal human lymphocytes. The behavior of the rats was observed before and 5, 10, 15, and 20 months after inoculation during a 30-min/rat testing time for 5 consecutive days. During each of 4 periods, a subset of rats was randomly chosen to be sacrificed in order to harvest the spinal cord for histopathological analysis and to obtain blood for serological and molecular studies. Behavioral analyses of the HTLV-1-inoculated rats showed a significant decrease of climbing, walking and freezing, and an increase of scratching, sniffing, biting, licking, and resting/sleeping. Two of the 25 HTLV-1-inoculated rats (8%) developed spastic paraparesis as a major behavioral change. The histopathological changes were few and mild, but in some cases there was diffuse lymphocyte infiltration. The minor and major behavioral changes occurred after 10-20 months of evolution. The long-term observation of Wistar rats inoculated with HTLV-1-infected MT2 cells showed major (spastic paraparesis) and minor motor abnormalities in association with the degree of HTLV-1-induced myelopathy.