Lobe-specific Expression of Phosphodiesterase 5 in Rat Prostate

OBJECTIVE To investigate the level and location of phosphodiesterase 5 (PDE5) expression in rat prostate. METHODS The ventral, dorsal, and lateral lobes of rat prostate were examined for PDE5 expression by Western blotting. Intact rat urogenital complex, including the urinary bladder and accessory reproductive glands, was examined for PDE5 expression by immunohistochemistry. Individual prostatic lobes were further examined by immunofluorescence for expression of PDE5, alpha-smooth muscle actin, and rat endothelial cell antigen. RESULTS Western blot analysis showed that PDE5 was expressed at a significantly lower level in dorsal lobe (DL) than in ventral lobe (VL) or lateral lobe (LL). Immunohistochemistry and immunofluorescence analyses showed that PDE5 was expressed in both acinar epithelium and periacinar smooth muscle. However, although similar levels of smooth muscle PDE5 expression were observed in all 3 prostatic lobes, significantly lower level of epithelial PDE5 expression was found in DL compared with VL or LL. In prostatic blood vessels, PDE5 expression was clearly visible in the endothelium but not as easily detectable in the smooth muscle. CONCLUSION PDE5 was expressed in the acinar epithelium and periacinar smooth muscle of rat prostate. However, the epithelial PDE5 expression was significantly less in DL than in VL or LL. Regardless, the acinar wall, not the blood vessel wall, is the predominant PDE5 expression site in rat prostate. (C) 2015 Elsevier Inc.

Maintaining internal representations: The role of the human superior parietal lobe

In sensorimotor integration, sensory input and motor output signals are combined to provide an internal estimate of the state of both the world and one's own body. Although a single perceptual and motor snapshot can provide information about the current state, computational models show that the state can be optimally estimated by a recursive process in which an internal estimate is maintained and updated by the current sensory and motor signals. These models predict that an internal state estimate is maintained or stored in the brain. Here we report a patient with a lesion of the superior parietal lobe who shows both sensory and motor deficits consistent with an inability to maintain such an internal representation between updates. Our findings suggest that the superior parietal lobe is critical for sensorimotor integration, by maintaining an internal representation of the body's state.

Design of surface emitting distributed feedback quantum cascade laser with single-lobe far-field pattern and high outcoupling efficiency

A 7.8-mu m surface emitting second-order distributed feedback quantum cascade laser (DFB QCL) structure with metallized surface grating is studied. The modal property of this structure is described by utilizing coupled-mode theory where the coupling coefficients are derived from exact Floquet-Bloch solutions of infinite periodic structure. Based on this theory, the influence of waveguide structure and grating topography as well as device length on the laser performance is numerically investigated. The optimized surface emitting second-order DFB QCL structure design exhibits a high surface outcoupling efficiency of 22% and a low threshold gain of 10 cm(-1). Using a pi phase-shift in the centre of the grating, a high-quality single-lobe far-field radiation pattern is obtained.

Investigations into the cellular and molecular changes in the amygdala in models of temporal lobe epilepsy and maternal immune activation

The amygdala is a limbic structure that is involved in many of our emotions and processing of these emotions such as fear, anger and pleasure. Conditions such as anxiety, autism, and also epilepsy, have been linked to abnormal functioning of the amygdala, owing to improper neurodevelopment or damage. This thesis investigated the cellular and molecular changes in the amygdala in models of temporal lobe epilepsy (TLE) and maternal immune activation (MIA). The kainic acid (KA) model of temporal lobe epilepsy (TLE) was used to induce Ammon’s-horn sclerosis (AHS) and to investigate behavioural and cytoarchitectural changes that occur in the amygdala related to Neuropeptide Y1 receptor expression. Results showed that KA-injected animals showed increased anxiety-like behaviours and displayed histopathological hallmarks of AHS including CA1 ablation, granule cell dispersion, volume reduction and astrogliosis. Amygdalar volume and neuronal loss was observed in the ipsilateral nuclei which was accompanied by astrogliosis. In addition, a decrease in Y1 receptor expressing cells in the ipsilateral CA1 and CA3 sectors of the hippocampus, ipsi- and contralateral granule cell layer of the dentate gyrus and ipsilateral central nucleus of the amygdala was found, consistent with a reduction in Y1 receptor protein levels. The results suggest that plastic changes in hippocampal and/or amygdalar Y1 receptor expression may negatively impact anxiety levels. Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the brain and tight regulation and appropriate control of GABA is vital for neurochemical homeostasis. GABA transporter-1 (GAT-1) is abundantly expressed by neurones and astrocytes and plays a key role in GABA reuptake and regulation. Imbalance in GABA homeostasis has been implicated in epilepsy with GAT-1 being an attractive pharmacological target. Electron microscopy was used to examine the distribution, expression and morphology of GAT-1 expressing structures in the amygdala of the TLE model. Results suggest that GAT-1 was preferentially expressed on putative axon terminals over astrocytic processes in this TLE model. Myelin integrity was examined and results suggested that in the TLE model myelinated fibres were damaged in comparison to controls. Synaptic morphology was studied and results suggested that asymmetric (excitatory) synapses occurred more frequently than symmetric (inhibitory) synapses in the TLE model in comparison to controls. This study illustrated that the amygdala undergoes ultrastructural alterations in this TLE model. Maternal immune activation (MIA) is a risk factor for neurodevelopmental disorders such as autism, schizophrenia and also epilepsy. MIA was induced at a critical window of amygdalar development at E12 using bacterial mimetic lipopolysaccharide (LPS). Results showed that MIA activates cytokine, toll-like receptor and chemokine expression in the fetal brain that is prolonged in the postnatal amygdala. Inflammation elicited by MIA may prime the fetal brain for alterations seen in the glial environment and this in turn have deleterious effects on neuronal populations as seen in the amygdala at P14. These findings may suggest that MIA induced during amygdalar development may predispose offspring to amygdalar related disorders such as heightened anxiety, fear impairment and also neurodevelopmental disorders.

Isolated conjugate gaze palsy after frontal lobe tumour surgery

Isolated conjugate gaze palsy following unilateral frontal lobe surgery is uncommon. When it does occur, usually it recovers within hours. We report a case of isolated conjugate gaze palsy which persisted for four weeks post-operatively before recovery commenced.

Problem-solving and spatial working memory in patients with schizophrenia and with focal frontal and temporal lobe lesions

Problem-solving ability was investigated in 25 DSM-IIIR schizophrenic (SC) patients using the Tower of Hanoi (TOH) task. Their performance was compared to that of: (1) 22 patients with neurosurgical unilateral prefrontal lesions, 11 left (LF) and 10 right hemisphere (RF); (2) 38 patients with unilateral temporal lobectomies, 19 left (LT) and 19 right (RT); and (3) 44 matched control subjects. Like the RT and LF group, the schizophrenics were significantly impaired on the TOH. The deficit shown by the schizophrenic group was equivalent whether or not the problems to be solved included goal-subgoal conflicts, unlike the LF group who were impaired specifically on these problems. The nature of the SC deficit was also distinct from that of the RT group, in that the problem-solving deficit remained after controlling for the effects of spatial memory performance. This study indicates, therefore, that neither focal frontal nor temporal lobe damage sustained in adult life is a sufficient explanation for the problem-solving deficits found in patients with schizophrenia. (C) 1999 Elsevier Science B.V. All rights reserved.

Frontal Lobe Function and Performance Monitoring following Total Sleep Deprivation

Imaging studies have shown reduced frontal lobe resources following total sleep deprivation (TSD). The anterior cingulate cortex (ACC) in the frontal region plays a role in performance monitoring and cognitive control; both error detection and response inhibition are impaired following sleep loss. Event-related potentials (ERPs) are an electrophysiological tool used to index the brain's response to stimuli and information processing. In the Flanker task, the error-related negativity (ERN) and error positivity (Pe) ERPs are elicited after erroneous button presses. In a Go/NoGo task, NoGo-N2 and NoGo-P3 ERPs are elicited during high conflict stimulus processing. Research investigating the impact of sleep loss on ERPs during performance monitoring is equivocal, possibly due to task differences, sample size differences and varying degrees of sleep loss. Based on the effects of sleep loss on frontal function and prior research, it was expected that the sleep deprivation group would have lower accuracy, slower reaction time and impaired remediation on performance monitoring tasks, along with attenuated and delayed stimulus- and response-locked ERPs. In the current study, 49 young adults (24 male) were screened to be healthy good sleepers and then randomly assigned to a sleep deprived (n = 24) or rested control (n = 25) group. Participants slept in the laboratory on a baseline night, followed by a second night of sleep or wake. Flanker and Go/NoGo tasks were administered in a battery at 1O:30am (i.e., 27 hours awake for the sleep deprivation group) to measure performance monitoring. On the Flanker task, the sleep deprivation group was significantly slower than controls (p's <.05), but groups did not differ on accuracy. No group differences were observed in post-error slowing, but a trend was observed for less remedial accuracy in the sleep deprived group compared to controls (p = .09), suggesting impairment in the ability to take remedial action following TSD. Delayed P300s were observed in the sleep deprived group on congruent and incongruent Flanker trials combined (p = .001). On the Go/NoGo task, the hit rate (i.e., Go accuracy) was significantly lower in the sleep deprived group compared to controls (p <.001), but no differences were found on false alarm rates (i.e., NoGo Accuracy). For the sleep deprived group, the Go-P3 was significantly smaller (p = .045) and there was a trend for a smaller NoGo-N2 compared to controls (p = .08). The ERN amplitude was reduced in the TSD group compared to controls in both the Flanker and Go/NoGo tasks. Error rate was significantly correlated with the amplitude of response-locked ERNs in control (r = -.55, p=.005) and sleep deprived groups (r = -.46, p = .021); error rate was also correlated with Pe amplitude in controls (r = .46, p=.022) and a trend was found in the sleep deprived participants (r = .39, p =. 052). An exploratory analysis showed significantly larger Pe mean amplitudes (p = .025) in the sleep deprived group compared to controls for participants who made more than 40+ errors on the Flanker task. Altered stimulus processing as indexed by delayed P3 latency during the Flanker task and smaller amplitude Go-P3s during the Go/NoGo task indicate impairment in stimulus evaluation and / or context updating during frontal lobe tasks. ERN and NoGoN2 reductions in the sleep deprived group confirm impairments in the monitoring system. These data add to a body of evidence showing that the frontal brain region is particularly vulnerable to sleep loss. Understanding the neural basis of these deficits in performance monitoring abilities is particularly important for our increasingly sleep deprived society and for safety and productivity in situations like driving and sustained operations.

Increased expression of "peripheral-type" benzodiazepine receptors in human temporal lobe epilepsy: implications for PET imaging of hippocampal sclerosis.

Increased binding sites for "peripheral-type" benzodiazepine receptor (PTBR) ligands have been described in a wide range of neurological disorders including both human and experimental epilepsy. This study was undertaken to assess PTBR expression in relation to the presence of hippocampal sclerosis in human temporal lobe epilepsy (TLE). For this purpose, hippocampal CA1 subfields were dissected from surgical samples from patients with therapy-refractive TLE with (n = 5) or without (n = 2) hippocampal sclerosis and from age-matched nonepileptic postmortem controls (n = 5). PTBR expression was assessed by immunohistochemistry and reverse-transcription polymerase chain reaction. Receptor sites were evaluated using an in vitro binding assay and the selective PTBR ligand [3H]PK11195. Epileptic patients with hippocampal sclerosis showed increases in PTBR binding sites, immunoreactivity, and mRNA expression compared to both nonsclerotic TLE patients and postmortem nonepileptic controls. Induction of PTBR expression and binding sites were directly correlated with the presence of hippocampal sclerosis and the accompanying reactive gliosis.

Friedensbilderbücher - Die österreichische Kinder- und Jugendbuchautorin Mira Lobe als Friedenserzieherin

Ce mémoire cherche à créer un dialogue entre les domaines de recherche du livre d’images et celui de recherches sur la paix afin d’exposer les différentes formes et fonctions des livres d’images pour la paix. Questionnant le pourquoi et le comment de ces œuvres, ce travail expose la façon et la manière avec lesquelles ces dernières contribuent à « l’alphabétisation de la paix » auprès des enfants et comment elles les motivent à agir en fonction de la paix. Les livres d’images constituent un média idéal pour éduquer les enfants à la paix. Très tôt dans le processus de socialisation, ces livres sauront transmettre et inculquer des concepts et aptitudes clefs et éventuellement ancrer dans l’esprit de l’enfant les valeurs d’une culture de la paix. Au centre de cette recherche est exposé le thème de la paix tel que traité à travers les œuvres de l’écrivaine autrichienne Mira Lobe (1913–1995). Par l’analyse de sept livres d’images pour la paix, ce travail explique quelles stratégies et méthodes littéraires, pédagogiques, sémiotiques, narratives et esthétiques sont employées par l’auteure pour réussir à bien présenter et à traiter de sujets politiques complexes et d’enjeux sociaux et humains parfois délicats et tabous à un jeune auditoire. Il montre également par quels moyens ces œuvres font naître l’empathie, une aversion pour la violence et comment elles pourront finalement amener les enfants à opter pour l’acte de la paix. En joignant et en mettant en relation les résultats et conclusions des deux champs de recherche observés dans ce travail, soit l’éducation à la paix et la recherche sur des livres d’images, il devient possible de démontrer comment Mira Lobe apporte, avec ses livres d’images pour la paix, une contribution universelle et intemporelle à l’éducation à la paix.

5-HT2C and NMDA Receptors, IP3, cGMP and cAMP Functional Regulation in Pilocarpine Induced Temporal Lobe Epilepsy in Rats: Neuroprotective Role of Bacopa monnieri

Department of Biotechnology, Cochin University of Science and Technology