Aging accentuates decrease in tyrosine hydroxylase immunoreactivity associated with the increase in the motor impairment in a model of reserpine-induced parkinsonism.

Parkinson's disease (PD) is an age-related neurodegenerative disorder characterized by progressive dopaminergic neuron loss. Animal models have been used to develop a better understanding of the pathophysiologic mechanisms of PD. However, these models are usually conducted with young animals diverging of the age of PD patients, suggesting a bias in translational science. Thus, the aim of the study was to evaluate the effect of the age on rats in a progressive parkinsonism model induced by reserpine (RES). Adult (6 - 8 month-old) or elderly (18 - 24 month-old) male rats were assigned to six groups: control-elderly (CTL-ELDERLY), reserpine-elderly (RES-ELDERLY), reserpine-elderly withdrawal (RES-ELDERLY WITHDRAWAL), control-adult (CTL-ADULT), reserpine-adult (RES-ADULT), and reserpine-adult withdrawal (RES-ADULT WITHDRAWAL). Animals received 15 injections every other day of RES (0.1 mg / kg) or vehicle during 30 days. Throughout treatment, animals were evaluated in the catalepsy test (every 48 h) and open field test (24 h after the second injection), and weight assessment (every 4 days) was also made. Upon completion of behavioral tests, rat brains were collected for tyrosine hydroxylase (TH) immunohistochemical analysis. Main results demonstrated that RES-treated animals spent more time in the catalepsy bar compared with control groups, moreover the RES-elderly group showed a longer catalepsy time compared with the RES-ADULT group. A shorter time from RES treatment to the development of symptoms was observed in the RES-ADULT group, compared with the RES-ELDERLY group. In addition, RES-induced weight loss in both RES-ELDERLY and RES-ADULT when compared with their corresponding controls. Cessation of RES treatment was followed by weight gain only in the RES-ADULT group. A significant decrease in TH-immunoreactive cells was observed in the substantia nigra pars compacta (SNpc) and dorsal striatum (STR) in the rats in both the RES-ADULT and RES-ELDERLY groups and in the ventral tegmental area in rats in the RES-ADULT group. Furthermore, TH immunoreactivity decrease was not reversible in SNpc and STR in the RES-ELDERLY. These results show that RES has an age-dependent effect in rats, suggesting a greater sensitivity of the dopaminergic pathway to RES with advancing age. These suggest that the RES rat model of parkinsonism can be useful in improving our knowledge on the effect of aging on neurodegeneration.

Nociception alterations precede motor symptoms in a progressive model of parkinsonism induced by reserpine in middle-aged rats.

Nociception alterations are frequent non-motor symptoms of the prodromal phase of Parkinson's disease (PD). The period for the onset of symptoms and the pathophysiological mechanisms underlying these alterations remain unclear. We investigated the course of nociception alterations in a progressive model of parkinsonism induced by reserpine (RES) in rats. Male Wistar rats (6-7 months) received 5 or 10 subcutaneous injections of RES (0.1 mg/kg) or vehicle daily for 20 days. Motor evaluation and nociceptive assessment were performed throughout the treatment. At the end of the treatment rats were euthanized, the brains removed and processed for immunohistochemical analysis (TH and c-Fos). The RES-treated rats exhibited an increased nociceptive response to mechanical and chemical stimulation in the electronic von Frey and formalin tests, respectively. Moreover, these alterations preceded the motor impairment observed in the catalepsy test. In addition, the RES treatment reduced the TH-immunoreactivity in the ventral tegmental area (VTA) and increased the c-Fos expression in the ventral-lateral periaqueductal gray (vlPAG), rostral ventral medulla (RVM) and dorsal raphe nucleus (DRN) after noxious stimuli induced by formalin. Taken together, our results reinforce that nociceptive changes are one of the early signs of PD and monoamine depletion in basal ganglia can be involved in the abnormal processing of nociceptive information in PD.

Telencephalic distributions of doublecortin and glial fibrillary acidic protein suggest novel migratory pathways in adult lizards.

Adult neurogenesis has been reported in all major vertebrate taxa. However, neurogenic rates and the number of neurogenic foci vary greatly, and are higher in ancestral taxa. Our study aimed to evaluate the distribution of doublecortin (DCX) and glial fibrillary acidic protein (GFAP) in telencephalic areas of the adult tropical lizard Tropidurus hispidus. We describe evidence for four main neurogenic foci, which coincide anatomically with the ventricular sulci described by the literature. Based on neuronal morphology, we infer four migratory patterns/pathways. In the cortex, patterns of GFAP and DCX staining support radial migrations from ventricular zones into cortical areas and dorsoventricular ridge. Cells radiating from the sulcus septomedialis (SM) seemed to migrate to the medial cortex and dorsal cortex. From the sulcus lateralis (SL), they seemed to be bound for the lateral cortex, central amygdala and nucleus sphericus. We describe a DCX-positive stream originating in the caudal sulcus ventralis and seemingly bound for the olfactory bulb, resembling a rostral migratory stream. We provide evidence for a previously undescribed tangential dorso-septo-caudal migratory stream, with neuroblasts supported by DCX-positive fibers. Finally, we provide evidence for a commissural migration stream seemingly bound for the contralateral nucleus sphericus. Therefore, in addition to two previously known migratory streams, this study provides anatomical evidence in support for two novel migratory routes in amniotes.

Balance alterations and reduction of pedunculopontine cholinergic neurons in early stages of parkinsonism in middle-aged rats.

The purpose of the present study was to investigate balance alterations and the possible role of the cholinergic neurons in the pedunculopontine nucleus (PPN) in the early stages of a progressive animal model of Parkinson's disease (PD). Twenty-eight middle-aged (8-9 months) male Wistar rats received 4 or 10 subcutaneous vehicle (control, CTL) or reserpine (RES) injections (0.1 mg/kg). The animals were submitted to different behavioral tests. Forty-eight hours after the 4th injection, half of the animals of each group (n = 7) were perfused and submitted to immunohistochemical analysis for tyrosine hydroxylase (TH) and choline acetyltransferase (ChAT). The remaining animals (n = 7 per group) were killed 48 h after the 10th injection. RES group presented motor deficits in the catalepsy and open field tests starting at days 12 and 20 of treatment, respectively (only for the animals that received 10 injections). On the other hand, dynamic and static balance changes were observed at earlier stages of RES treatment, starting at days 6 and 4, respectively. At this point of the treatment, there was no decrease in the number of TH immunoreactivity neurons in the substantia nigra pars compacta (SNpc), ventral tegmental area (VTA) and dorsal striatum (DS). However, a decrease was observed in SNpc and dorsal striatum of animals that received 10 injections. In contrast, there was a decrease in the number of ChAT immunoreactive cells in PPN concomitantly to the balance alterations at the early stages of treatment (after 4 RES injections). Thus, by mimicking the progressiveness of PD, the reserpine model made it possible to identify static and dynamic balance impairments prior to the motor alterations in the catalepsy and open field tests. In addition, changes in balance were accompanied by a reduction in the number of ChAT immunoreactive cells in NPP in the early stages of treatment.

Short-term but not long-term exposure to an enriched environment facilitates the extinction of aversive memory.

Environmental enrichment (EE) has been used to investigate behavioral changes and neuroplasticity in brain in normal and pathological conditions. Besides, the EE has been used to understand the neurobehavioral systems involved in learning experiences, visual inputs, defensive responses, social interactions and memory. However, the required exposure duration to remove aversive memories remains lacking. Therefore, the purpose of the present study was to investigate the time-course effect of EE exposure on the extinction of aversive memory. Young adult male Wistar rats were exposed to two different EE protocols: short-term environmental enrichment (EE2 - animal kept under enriched conditions for two weeks) and long-term environmental enrichment (EE4 - animal kept under enriched conditions for four weeks). The contextual fear conditioning test was used to assess aversive memory. The both EE protocols provide changes in Zif-268 immunoreactivity in mesocorticolimbic areas such as CA1 and central amygdala; however, only short-term EE reduces the ZIF-268 immunoreactivity in VTA. Besides, both EE protocols also provide an increase in TH immunoreactivity in VTA and nucleus accumbens, but only the short-term EE modifies the TH immunoreactivity in CA1 and infralimbic region of the prefrontal cortex. The time-course effect of EE interferes differently on the extinction of aversive memory, being two weeks of exposure with EE sufficient to cause improvement in coping during aversive situations, favoring the extinction of conditioned fear memory.

Intracerebroventricular injection of deltamethrin increases locomotion activity and causes spatial working memory and dopaminergic pathway impairment in rats.

Deltamethrin (DM) is widely used in agriculture, veterinary medicine and control of domestic pests. Epidemiological studies suggest that DM exposure is a risk factor for neurodegenerative disorders such as Parkinson's (PD) and Alzheimer diseases; however the mechanisms are elusive. In the present study we evaluated the effects of intracerebroventricular (i.c.v.) administration of DM on locomotion activity, spatial working memory and dopaminergic pathway in the rat. Middle-aged male Wistar rats received three i.c.v. injections of DM 0.5 µg, DM 5 µg or vehicle, every other day. Across the treatment, the animals were submitted to behavioral evaluation in the catalepsy test, open field test, and spontaneous alternation task. Following completion of behavioral tests, rats were perfused and their brains were processed to tyrosine hydroxylase (TH) immunohistochemistry. We observed that i.c.v. administration of DM 5 µg increased locomotion activity (open field) and caused spatial working memory impairment (spontaneous alternation task). These alterations were accompanied by reduction TH immunoreactivity in the substantia nigra pars compacta (SNpc), ventral tegmental area (VTA) and dorsal striatum. Conversely, no motor change was observed in the catalepsy test. These results indicate that i.c.v. administration of DM can cause hyperactivity and cognitive alteration which may be related to disruption of the dopaminergic pathway.

Sex differences in the progressive model of parkinsonism induced by reserpine in rats.

Parkinson's disease (PD) exhibits sexual differences in susceptibility and pathogenesis in humans, with a high incidence in men and a high severity of motor symptoms in male rodents. Furthermore, studies showed that the administration of low dose of reserpine (RES) induces a progressive appearance of motor alterations similar with parkinsonism in male rodents. Here, we investigated sex differences in motor deficits and tyrosine hydroxylase (TH) immunoreactivity induced by a progressive model of parkinsonism. Gonadally intact male and female Wistar rats and ovariectomized female rats received 15 subcutaneous injections (s.c.) every other day of 0.1 mg/kg of RES or vehicle. The repeated administration of low doses of RES (0.1 mg/kg) produces sexually dimorphic impairments on motor performance (catalepsy and open field test). Intact and ovariectomized females were more resistant to the deleterious effect of repeated administration of reserpine in the early, but this resistance in intact female disappears over time. However, intact females showed a reduction of the TH immunoreactivity in substantia nigra pars compacta, but not in ventral tegmental area and dorsal striatum. These results suggest a possible application of this model in the study of sexual dimorphism throughout the progression of PD.

Serotonergic dysfunction in a model of parkinsonism induced by reserpine.

Parkinson's disease (PD) is mainly characterized by a dopamine deficiency accompanied by structural and functional changes in striatal neuronal projections. However, studies have considered PD as a multi-systemic disease in which the neurodegenerative process extends beyond the dopaminergic system. Therefore, the purpose of the present study was to investigate the time-course of serotonergic neuron damage in a progressive model of parkinsonism induced by a low dose of reserpine. Thus, male Wistar rats received 4 (ST, short-treatment of reserpine) or 10 (MT, middle-term treatment of reserpine) subcutaneous injections of vehicle or reserpine (0.1 mg/kg) at a volume of 1 mL/kg body weight, on alternate days. Animals were euthanized 48 h after the last injection for immunohistochemical analysis. After ST, 5-HT immunoreactivity decreased in hippocampal subareas (CA1 and CA3) and medial prefrontal cortex (mPFC) compared to vehicle. Furthermore, animals MT-treated also showed progressive decrease of 5-HT immunoreactivity in CA1 and CA3 subareas. Conversely, a significant increase of 5-HT immunoreactivity was found in mPFC and dorsal raphe nucleus (DRN) in animals submitted to MT when compared to ST exposure. The results showed that, in the repeated low-dose reserpine rat model, variations in the immunoreactivity of 5-HT start early in the course of progressive parkinsonism.

Depressant effect of geraniol on the central nervous system of rats: Behavior and ECoG power spectra.

Geraniol is a monoterpene alcohol that is derived from the essential oils of aromatic plants, with anti-inflammatory, antimicrobial, antioxidant and neuroprotective properties. This study characterized the effect of geraniol on behavior and brainwave patterns in rats. Male rats were submitted to administration of geraniol (25, 50 and 100 mg/kg). The hole board (HB) and open field (OF) tests were performed to evaluate anxiety and motor behavior, respectively. In addition, barbiturate-induced sleeping time (BIST) was used to analyze sedative effect. Finally, electrocorticogram (ECoG) recordings were used to characterize brain-wave patterns. The results showed that geraniol treatment in rats decreased the distance traveled, rearing numbers and lead to increase in immobility time in HB and OF tests. In BIST test, geraniol treatment increased sleep duration but not sleep latency in the animals. Furthermore, geraniol-treated animals demonstrated an increase in the percentage of delta waves in the total spectrum power. Taken together, our results suggested that geraniol exerted a depressant effect on the central nervous system of rats.

The Impact of Yoga Nidra and Seated Meditation on the Mental Health of College Professors.

BACKGROUND: World statistics for the prevalence of anxiety and mood disorders shows that a great number of individuals will experience some type of anxiety or mood disorder at some point in their lifetime. Mind-body interventions such as Hatha Yoga and seated meditation have been used as a form of self-help therapy and it is especially useful for challenging occupations such as teachers and professors. AIMS: In this investigation, we aimed at observing the impact of Yoga Nidra and seated meditation on the anxiety and depression levels of college professors. MATERIALS AND METHODS: Sixty college professors, men and women, aged between 30 and 55 years were randomly allocated in one of the three experimental groups: Yoga Nidra, seated meditation, and control group. Professors were evaluated two times throughout the 3-month study period. Psychological variables included anxiety, stress, and depression. RESULTS: Data analysis showed that the relaxation group presented better intragroup results in the anxiety levels. Meditation group presented better intragroup results only in the anxiety variable (physical component). Intergroup analysis showed that, except for the depression levels, both intervention groups presented better results than the control group in all other variables. CONCLUSIONS: Prepost results indicate that both interventions represent an effective therapeutic approach in reducing anxiety and stress levels. However, there was a tendency toward a greater effectiveness of the Yoga Nidra intervention regarding anxiety, which might represent an effective tool in reducing both cognitive and physiological symptoms of anxiety.

Excitotoxic lesion of the medial prefrontal cortex in Wistar rats: Effects on trait and state anxiety.

The neural substrate of anxiety response (state anxiety) to a threatening situation is well defined. However, a lot less is known about brain structures implicated in the individual's predisposition to anxiety (trait anxiety). Scientific evidences lead us to suppose that the medial prefrontal cortex (mPFC) is involved in both trait and state anxiety. Thus, the aim of this study was to investigate the involvement of mPFC in trait anxiety and to further evaluate its participation in state anxiety. Sixty six adult, Wistar, male rats were first tested in the free-exploratory paradigm (FEP) and were categorized according to their levels of trait anxiety (high, medium and low). Three to six days after this exposure, all animals were submitted to stereotaxic brain surgery. Half the animals from each anxiety category was allocated to the mPFC-lesioned group and the other half to the Sham-lesioned group. After seven to nine days, all animals were again tested in FEP. Eight to 10 days later, the animals were tested in the Hole Board test, a model of state anxiety. The mPFC lesion decreased levels of trait anxiety of highly anxious rats, whereas it reduced the state anxiety of all animals, regardless the level of trait anxiety. These data extend evidence of the participation of the mPFC in state anxiety and it demonstrate the involvement of this brain structure in trait anxiety, a personality trait supposed to be a predisposing factor for anxiety disorders.

Deltamethrin Intranasal administration induces memory, emotional and tyrosine hydroxylase immunoreactivity alterations in rats.

Parkinson's disease (PD) is a neurodegenerative disease related to the dopaminergic system. The etiology is not fully understood, but it is known that PD is a multifactorial disease that involves genetic and environmental factors, including pesticides. One of these, Deltamethrin (DM), has been widely used for vector control in crops, farming, veterinary medicine and domestic pest control. The purpose of the present study was to investigate the effect of DM repeated administration on motor, cognitive and emotional behavior and dopaminergic parameters. Male Wistar rats received 3 intranasal (i.n.) injections of 100 µL (50 µL/nostril) of DM 0.5 µg/µl or Vehicle (saline solution 0.9%), one injection per week. We observed that DM caused memory (novel object recognition task) and emotion (contextual conditioned fear) alterations accompanied by reduction of TH immunoreactivity in the substantia nigra pars compacta (SNpc) and ventral tegmental area (VTA), and increase of TH immunoreactivity in the dorsal striatum. Motor alterations (catalepsy and open field task) were not observed throughout treatment. These findings suggest a possible early disruption of the dopaminergic pathway caused by repeated DM exposure, similar to that observed in early stages of PD.

Carvacrol prevents impairments in motor and neurochemical parameters in a model of progressive parkinsonism induced by reserpine.

Parkinson's disease (PD) is a neurodegenerative disease characterized by a progressive degeneration of dopaminergic neurons in the substantia nigra pars compact (SNpc), with consequent depletion of dopamine in the striatum, which gives rise to the characteristic motor symptoms of PD. Although its etiology is unknown, several studies have suggested that oxidative stress plays a critical function in the pathophysiology of PD, and antioxidant agents could be helpful to slown down the dopaminergic neurodegeneration. Carvacrol (CA) is a phenolic monoterpene found in essential oils of many aromatic plants that presents antioxidant and neuroprotective effects. This study aimed to assess the effect of CA in a reserpine (RES)-induced rat model of PD. Male Wistar rats received 15 s.c. injections of 0.1 mg/kg RES or vehicle, every other day, concomitantly to daily i.p. injections of CA (12.5 or 25 mg/kg) or vehicle. Across the treatment, the animals were submitted to behavioral evaluation in the catalepsy test (performed daily), open field test (7th day) and assessment of vacuous chewing movements (12th, 20th and 30th days). Upon completion of behavioral tests, rats were perfused and their brains underwent tyrosine hydroxylase (TH) immunohistochemical analysis. Our results showed that CA (12.5 e 25 mg/kg) prevented the increase in catalepsy behavior and number of vacuous chewing movements, but failed to revert the decreased open-field locomotor activity induced by RES. In addition, CA in both doses prevented the decrease in TH immunostaining induced by RES in the SNpc and dorsal striatum. Taken together, our results suggest that CA shows a protective effect in a rat model of PD, preventing motor and neurochemical impairments induced by RES. Thus, the use of CA as a promising new strategy for the prevention and/or treatment of PD may be considered.

Passiflora cincinnata Extract Delays the Development of Motor Signs and Prevents Dopaminergic Loss in a Mice Model of Parkinson's Disease.

Passiflora cincinnata Masters is a Brazilian native species of passionflower. This genus is known in the American continent folk medicine for its diuretic and analgesic properties. Nevertheless, few studies investigated possible biological effects of P. cincinnata extracts. Further, evidence of antioxidant actions encourages the investigation of possible neuroprotective effects in animal models of neurodegenerative diseases. This study investigates the effect of the P. cincinnata ethanolic extract (PAS) on mice submitted to a progressive model of Parkinson's disease (PD) induced by reserpine. Male (6-month-old) mice received reserpine (0.1 mg/kg, s.c.), every other day, for 40 days, with or without a concomitant treatment with daily injections of PAS (25 mg/kg, i.p.). Catalepsy, open field, oral movements, and plus-maze discriminative avoidance evaluations were performed across treatment, and immunohistochemistry for tyrosine hydroxylase was conducted at the end. The results showed that PAS treatment delayed the onset of motor impairments and prevented the occurrence of increased catalepsy behavior in the premotor phase. However, PAS administration did not modify reserpine-induced cognitive impairments. Moreover, PAS prevented the decrease in tyrosine hydroxylase immunostaining in the substantia nigra pars compacta (SNpc) induced by reserpine. Taken together, our results suggested that PAS exerted a neuroprotective effect in a progressive model of PD.

Essential Oil of Ocimum basilicum L. and (-)-Linalool Blocks the Excitability of Rat Sciatic Nerve.

The racemate linalool and its levogyrus enantiomer [(-)-LIN] are present in many essential oils and possess several pharmacological activities, such as antinociceptive and anti-inflammatory. In this work, the effects of essential oil obtained from the cultivation of the Ocimum basilicum L. (EOOb) derived from Germplasm Bank rich in (-)-LIN content in the excitability of peripheral nervous system were studied. We used rat sciatic nerve to investigate the EOOb and (-)-LIN effects on neuron excitability and the extracellular recording technique was used to register the compound action potential (CAP). EOOb and (-)-LIN blocked the CAP in a concentration-dependent way and these effects were reversible after washout. EOOb blocked positive amplitude of 1st and 2nd CAP components with IC50 of 0.38 ± 0.2 and 0.17 ± 0.0 mg/mL, respectively. For (-)-LIN, these values were 0.23 ± 0.0 and 0.13 ± 0.0 mg/mL. Both components reduced the conduction velocity of CAP and the 2nd component seems to be more affected than the 1st component. In conclusion EOOb and (-)-LIN inhibited the excitability of peripheral nervous system in a similar way and potency, revealing that the effects of EOOb on excitability are due to the presence of (-)-LIN in the essential oil.

Characterization of NADPH Diaphorase- and Doublecortin-Positive Neurons in the Lizard Hippocampal Formation.

The lizard cortex has remarkable similarities with the mammalian hippocampus. Both regions process memories, have similar cytoarchitectural properties, and are important neurogenic foci in adults. Lizards show striking levels of widespread neurogenesis in adulthood and can regenerate entire cortical areas after injury. Nitric oxide (NO) is an important regulatory factor of mammalian neurogenesis and hippocampal function. However, little is known about its role in nonmammalian neurogenesis. Here, we analyzed the distribution, morphology, and dendritic complexity (Neurolucida reconstructions) of NO-producing neurons through NADPH diaphorase (NADPHd) activity, and how they compare with the distribution of doublecortin-positive (DCX+) neurons in the hippocampal formation of the neotropical lizard Tropidurus hispidus. NADPHd-positive (NADPHd+) neurons in the dorsomedial cortex (DMC; putatively homologous to mammalian CA3) were more numerous and complex than the ones in the medial cortex (MC; putatively homologous to the dentate gyrus). We found that NADPHd+ DMC neurons send long projections into the MC. Interestingly, in the MC, NADPHd+ neurons existed in 2 patterns: small somata with low intensity of staining in the outer layer and large somata with high intensity of staining in the deep layer, a pattern similar to the mammalian cortex. Additionally, NADPHd+ neurons were absent in the granular cell layer of the MC. In contrast, DCX+ neurons were scarce in the DMC but highly numerous in the MC, particularly in the granular cell layer. We hypothesize that NO-producing neurons in the DMC provide important input to proliferating/migrating neurons in the highly neurogenic MC.

The anticonvulsant effect of geraniol and inclusion complex geraniol: beta-cyclodextrin / El efecto anticonvulsivo de geraniol y la inclusión de geraniol complejo: beta-ciclodextrina

Geraniol (GR) is an acyclic monoterpene alcohol present in essential oils of aromatic plant species used in Brazilian folk medicine for the treatment of epilepsy. The present study was designed to evaluate the anticonvulsant effect of GR and of the inclusion complex geraniol:beta-cyclodextrin (GR:beta-CD). Mice were treated with GR or with GR:beta-CD (50, 100 and 200 mg/kg) 30 min before pentylenetetrazole (PTZ) or strychnine (STN). GR at 200 mg/kg and GR:beta-CD at the doses of 100 and 200 mg/kg significantly increased the latency for the first PTZ-induced convulsion and reduced the percentage of animals that convulsed. The pretreatment of flumazenil did not revert the anticonvulsant effect of GR in the PTZ-induced convulsion model. In the STN-induced convulsion model, the effects of GR were investigated and no difference was found against control. The results demonstrated an anticonvulsant activity of GR in the PTZ-model, which was potentialized by the complexation with beta-CD...

Geraniol (GR) es un alcohol monoterpeno acíclico presentes en los aceites esenciales de las especies de plantas aromáticas utilizadas en la medicina popular brasileña para el tratamiento de la epilepsia. El presente estudio fue diseñado para evaluar el efecto anticonvulsivo del GR y de la inclusión de geraniol complejo: beta-ciclodextrina (GR:beta-CD). Los ratones fueron tratados con GR o con GR:beta- CD (50, 100 y 200 mg/kg) 30 minutos antes de pentylenotetrazole (PTZ) o strichinine (STN). GR a 200 mg/kg y GR:beta-CD en las dosis de 100 y 200 mg/kg aumentó significativamente la latencia para la primera convulsión inducida PTZ-y redujo la porcentaje de animales que convulsionó. El tratamiento previo de flumazenil no revirtió el efecto anticonvulsivo de GR en el modelo de convulsión inducida con PTZ. En el modelo de convulsión inducida com STN, los efectos de GR fueron investigados y no se encontró ninguna diferencia contra el control. Los resultados demostraron una actividad anticonvulsiva de geraniol en el modelo de PTZ, que fue potenciada por la formación de complejos con beta-CD...

Low temperature-acclimation impairs cellular migration in the adult cerebral cortex of the tropical lizard, Tropidurus hispidus (Spix, 1825) (Squamata: Tropiduridae).

The effects of different temperature-acclimations on cellular proliferation and migration were studied in the cerebral cortex of the tropical lizard, Tropidurus hispidus. Lizards were divided in two groups: warm-acclimated lizards (WALs), maintained at the temperature and photoperiod conditions of their natural habitat (mean temperature 26°C; 12:12 light:dark) and the cold-acclimated lizards (CALs), maintained at the same cycle of illumination and a mean temperature of 16°C. Animals were injected with the proliferative marker 5-bromodeoxyuridine (BrdU) and euthanized fifteen or thirty days later for the immunostaining. There was no difference in the number of BrdU-positive nuclei between the experimental groups in any of the cortical layers. In CALs, the positive nuclei were found mostly close to the ependyma, whereas in WALs many positive nuclei were also found in the plexiform and cellular layers of the cortex. In CALs, BrdU-positive nuclei appeared grouped (of 2-3 nuclei), a characteristic not seen in the other group. These data suggest that temperature affects the migrating capability of the newly generated neurons in the lizard cortex, but appears not to interfere with its generation.

Epidemiological aspects of dengue in Aracaju, State of Sergipe, Brazil / Aspectos epidemiológicos da dengue em Aracaju, Estado de Sergipe, Brasil

INTRODUCTION: The dengue fever remains to be a disease of serious public health concern, and its incidence has increased in the past decades. This study aimed to characterize the epidemiological incidence of dengue in the period 2001-2010. METHODS: This is an epidemiological study of dengue in the municipality of Aracaju, state of Sergipe, in the period between 2001 and 2010, whose data were obtained from the Information System of Diseases Notifications. A descriptive analysis of the number of confirmed cases of dengue, according to year, semester, sanitary district, age, and sex, was performed. RESULTS: There were 16,462 confirmed cases, especially in 2008, which obtained the highest incidence of the disease, with 10,485 confirmed cases. The first semester obtained the highest registration of cases during the years of research; this was predominated by females between 15 and 49 years old. With regard to the territorial distribution, the second district of the municipality obtained the highest number of cases. CONCLUSIONS: In 2008, in the City of Aracaju, SE, a significant increase in the proportion of dengue cases compared with other years was verified. However, a fast decline in the other years was observed, possibly because of the intensification of preventive actions to combat the mosquito that transmits the dengue virus.

INTRODUÇÃO: A dengue permanece como uma doença de elevada significância para a saúde pública e sua incidência tem aumentado nas últimas décadas. Este estudo objetivou caracterizar a incidência epidemiológica da dengue no período de 2001-2010. MÉTODOS: Trata-se de um estudo epidemiológico da dengue no município de Aracaju, Sergipe, no período de 2001 a 2010, cujos dados foram obtidos do Sistema de Informação de Agravos de Notificações. Foi realizada a análise descritiva do número de casos confirmados de dengue segundo ano, semestre, distrito sanitário, faixa etária e sexo. RESULTADOS: Foram confirmados 16.462 casos, com destaque para o ano de 2008, o qual obteve maior incidência da doença, com 10.485 casos confirmados. O primeiro semestre obteve maior registro dos casos em todos os anos da pesquisa, com predomínio do sexo feminino e da faixa etária de 15-49 anos. Com relação à distribuição territorial, destaque para o segundo distrito do município que apresentou maior número de casos. CONCLUSÕES: Verificou-se que no ano de 2008, na Cidade de Aracaju, SE, houve aumento significativo da proporção de casos de dengue em relação aos demais anos. No entanto, nota-se um declínio vertiginoso nos anos posteriores, possivelmente devido à intensificação de ações de prevenção e combate ao mosquito transmissor do vírus da dengue.