Glymphatic system and aquaporin­4 in epilepsy.

Over the past decade glymphatic concept has gained more and more interest. Despite some lacking data regarding structural and functional aspects, glymphatic system is widely considered the main mechanism of water and solutes transport in brain parenchyma, as well as waste clearance from the brain. Glymphatic system modulates the extracellular space volume and is involved in spatial K+ buffering (via influencing Kir4.1 channel functioning), two factors crucial for neuronal excitability and seizure susceptibility, and is itself strongly stimulated during sleep. This review summarizes information regarding the potential role of the glymphatic system in the development and progression of epilepsy, especially the role of the glial water channel aquaporin­4 in modulation of brain excitability and in epilepsy. Data from animal models and human studies are presented.

Correlation of the ALA-PDT Treatment Efficacy and the HPV Genotype Profile of Genital Warts after Cryotherapy Failure and Podophyllotoxin Therapy in Male Patients.

BACKGROUND: Genital warts are the manifestation of the human papillomavirus (HPV) infection, which may last for weeks or months before the clinical presentation. The primary aim of the study was the correlation of the DNA HPV genotypes eradication with the treatment response in male patients with persistent genital warts. METHODS: Twenty-one male patients (age range: 22-58) after failure of cryotherapy and podophyllotoxin treatment were enrolled in the study. Genetic tests (Real Time - PCR method) analyzed the presence of DNA-HPV before and 6 months after four sessions (4 weeks apart) of photodynamic therapy with 5-aminolaevulinic acid (ALA-PDT). The treatment efficacy was evaluated before each PDT session and at the end of the study. RESULTS: The single HPV DNA type was present in 15/21 of the patients (13/15 HPV6). The high-risk HPV types were found in 8/21 subjects, of which 6/8 had several types. Six months after four sessions of PDT, complete response was found in 16/21 (76.19%; p = 0.0007) of patients, and DNA HPV clearance was found in 66.67% (p = 0.03). The eradication rate differed among patients with primary low-risk and high-risk HPV types-76.92% (10/13; p = 0.0003) and 50% (4/8; p = 0.05) respectively. CONCLUSION: ALA-PDT is an effective treatment even after the failure of previous modalities. The persistence of clinical lesions and high oncological risk HPV types should be an indication for treatment prolongation.

Hyaluronidase inhibition accelerates functional recovery from stroke in the mouse brain.

Perineuronal nets (PNNs) are presumed to limit plasticity in adult animals. Ischaemic stroke results in the massive breakdown of PNNs resulting in rejuvenating states of neuronal plasticity, but the mechanisms of this phenomenon are largely unknown. As hyaluronic acid (HA) is the structural backbone of PNNs, we hypothesized that these changes are a consequence of the altered expression of HA metabolism enzymes. Additionally, we investigated whether early hyaluronidase inhibition interferes with post-stroke PNN reduction and behavioural recovery. We investigated the mRNA/protein expression of these enzymes in the perilesional, remote and contralateral cortical regions in mice at different time points after photothrombosis, using quantitative real-time polymerase chain reaction and immunofluorescence. A skilled reaching test was employed to test hyaluronidase inhibitor L-ascorbic acid 6-hexadecanoate influence on post-stroke recovery. We found the simultaneous up-regulation of mRNA of HA synthesizing and degrading enzymes in the perilesional area early after stroke, suggesting an acceleration of HA turnover in ischaemic animals. Immunostaining revealed differential cellular localization of enzymes, with hyaluronidase 1 in astrocytes and hyaluronan synthase 2 in astrocytes and neurons, and post-stroke up-regulation of both of them in astrocytes. ß-glucuronidase was observed in neurons but post-stroke up-regulation occurred in microglia. Inhibition of hyaluronidase activity early after stroke resulted in improved performance in skilled reaching test, without affecting the numbers of PNNs. These results suggest that after stroke, a substantial reorganization of polysaccharide content occurs, and interfering with this process at early time has a beneficial effect on recovery.

Chondroitin sulfate metabolism in the brain.

Over the last twenty years chondroitin sulfate (CS) has become a focus of interest of neuroscience due to its indubitable role in shaping axonal growth, synaptic plasticity and glial scar forming. Various patterns of sulfation give rise to various CS molecules with different properties that are capable of interactions with a plethora of molecules, including growth factors, receptors and guidance molecules. The involvement of CS chains has been implicated in visual critical period regulation, memory formation, spinal cord regeneration. As part of proteoglycan molecules, they are widely expressed in the central nervous system, however, little is known about the enzymatic machinery responsible for CS synthesis and degradation. In this review we attempt to extract and collect the available information concerning the expression and function of enzymes of CS metabolism in the brain.

Seropositive bucks and within-herd prevalence of small ruminant lentivirus infection.

Caprine arthritis-encephalitis is an economically important disease of goats. It is evident that horizontal transmission through respiratory secretions and milk plays an important part in the disease spread whereas the role of sexual transmission remains questionable. The cross-sectional study was carried out to investigate the relationship between presence of small ruminant lentivirus (SRL V)-seropositive bucks and seroprevalence of SRL V infection in does in herds. The analysis included 76 goat herds seropositive for SRL V infection. A sample of adult female goats from each herd was selected in a simple random fashion. All males present in a herd were also enrolled in the study. The animals were screened with commercial serological immunoenzymatic tests. Standardized questionnaires were used to gather knowledge of 3 hypothesized herd-level confounding factors: number of years for which a herd had existed until testing, goat replacement from other herds in Poland and use of machine milking. Three-level hierarchical linear regression model was developed to evaluate the relationship (α = 0.05). Median (interquartile range) within-herd seroprevalence of SRL V was 60.1% (35.7% to 87.9%) and 35.8% (10.1% to 49.6%) in herds where seropositive males were present and absent, respectively. Controlling for possible confounders presence of SRL V-seropositive bucks proved to be an independent factor linked to the higher within-herd seroprevalence of SRL V (p = 0.001). The study indicates that seropositive bucks may facilitate the spread of SRL V infection in goat herds and therefore their presence should be considered as a risk factor.

Influence of small ruminant lentivirus infection on cheese yield in goats.

Three-year cohort study was carried out to investigate the influence of small ruminant lentivirus (SRLV) infection on cheese yield in goats. For this purpose records of milk yield, milk composition and cheese yield were collected in a dairy goat herd. Cheese yield was recorded as the amount of fresh cheese obtained from 1 kg milk. All goats were serologically tested for SRLV infection twice a year. The analysis included 247 records in total (71 for seropositive and 176 from seronegative individuals) and was carried out with the use of the four-level hierarchical linear model (α = 0·05). SRLV infection proved to be a statistically significant independent factor reducing cheese yield (P = 0·013)--when other covariates were held constant cheese yield was reduced by 4·6 g per each 1 kg milk in an infected goat compared with an uninfected goat. Other statistically significant covariates positively associated with cheese yield were protein contents, fat contents and the 3rd stage of lactation (P < 0·001 for all).

Biodegradation of oxyethylated fatty alcohols by bacteria Microbacterium strain E19.

The Microbacterium sp. E19 (E19) has been isolated from soil contaminated with crude oil and is a candidate for surfactant enhanced remediation of hydrocarbon polluted soil. Oxyethylated alcohols (OA) are candidates for this process enhancement. The aim of this work was the investigation of biodegradation of a representative oxyethylated fatty alcohol (polydispersal surfactant C12E10(C12E10)) by E19 under static model conditions with the surfactant as a sole source of organic carbon. LC-MS was used for the identification of metabolites and determination of surfactant and metabolite concentrations. Apart from [M+NH4](+) ethoxylate 'fingerprints', [M+2NH4](++) 'fingerprints' (m/z=22) were used for the identification of particular species. Primary biodegradation of C12E10 by E19 is almost complete over 30 days of the test (97 percent). The major metabolites during the initial period of the test are homologs of oxyethylated alcohols ω-carboxylated in the oxyethylene chain and poly(ethylene glycols). 1/3 of the total C12Ex is metabolized along this pathway. Concentration of these metabolites is stable over the subsequent days of the test. Further biodegradation of C12Ex causes an enrichment of the residue with C12Ex homologs having a longer oxyethylene chain. However, intermediates of this process were not identified.

Risk factors associated with seropositivity to small ruminant lentiviruses in goat herds.

Cross-sectional studies based on serological testing and questionnaires were conducted at 5-yr intervals (1996, 2002 and 2007) in goat breeding herds from Poland to determine true herd-level seroprevalence of caprine arthritis-encephalitis and the herd-level risk factors for seropositivity. Multivariable logistic regression models were developed for data from 1996 and the combined data from 2002 and 2007, separately. True herd-level seroprevalences in 1996, 2002 and 2007 were 30.8% (CI 95%: 20.5-41.0%), 65.7% and 71.9%, respectively. The import of goats from abroad was a risk factor only in 1996 (OR 13.6, CI 95%: 1.14-162). The presence of seropositive bucks in a herd was a risk factor in 1996 (OR 21, CI 95%: 1.89-233) and in 2002-2007 (OR 2.9, CI 95%: 1.04-8.4). Moreover, large herds (>30 does in 1996 or >100 does in 2002-2007) were more likely to be seropositive than smaller herds (OR=10.1, CI 95%: 2.17-46 in 1996 and OR 5.4, CI 95%: 1.11-26 in 2002-2007).

Comparison of matrix metalloproteinase activation after focal cortical ischemia in young adult and aged mice.

Matrix metalloproteinase (MMP) activity is implicated in the degradation of the extracellular matrix during cerebral ischemia. Although many studies have demonstrated spatiotemporal patterns of activation of gelatinases (MMP-9 and MMP-2) after ischemic stroke in young adult rodents, no data exist on MMP activity in old brains. In this study, we investigated the gelatinolytic activity in young adult (3-month-old) and aged (1-year-old) mice subjected to photothrombotic stroke. Using in situ zymography and gel zymography, we found that the basal gelatinolytic activity in the intact cerebral cortex was similar at both investigated ages. Similarly, after photothrombosis, the increased gelatinolytic response up to 7 days poststroke was the same in young and aged brains. At both ages, early activation of gelatinolysis in the ischemic core and the perilesional area was present in neuronal nuclei as revealed by colocalization of gelatinolytic product with NeuN immunostaining and DAPI. Additionally, application of specific antibodies against MMP-9 and MMP-2 revealed the increase in MMP-9 immunoreactivity in cell nuclei as early as 4 hr poststroke. No differences between young and aged mice were observed concerning the level and localization of MMP-9 immunoreactivity. The lack of age-related differences in the degree and pattern of activation of gelatinolysis after focal stroke and the lack of correspondence between the results of in situ and gel zymography suggest that extracellular proteolysis is not directly responsible for the more severe outcome of ischemic stroke in aged subjects.

Disturbance of perineuronal nets in the perilesional area after photothrombosis is not associated with neuronal death.

Perineuronal nets (PNNs) are a condensed form of extracellular matrix that covers the surface of a subset of neurons. Their presence limits neuronal plasticity and may protect neurons against harmful agents. Here we analyzed the relationship between spatiotemporal changes in PNN expression and cell death markers after focal cortical photothrombotic stroke in rats. We registered a substantial decrease in PNN density using Wisteria floribunda agglutinin staining and CAT-315 and brevican immunoreactivity; the decrease occurred not only in the lesion core but also in the perilesional and remote cortex as well as in homotopic contralateral cortical regions. Fluoro Jade C and TUNEL staining in perilesional and remote areas, however, showed a low density of dying cells. Our results suggest that the PNN reduction was not a result of cellular death and could be considered an attempt to create conditions favorable for synaptic remodeling.

Exercise-induced motor improvement after complete spinal cord transection and its relation to expression of brain-derived neurotrophic factor and presynaptic markers.

BACKGROUND: It has been postulated that exercise-induced activation of brain-derived neurotrophic factor (BDNF) may account for improvement of stepping ability in animals after complete spinal cord transection. As we have shown previously, treadmill locomotor exercise leads to up-regulation of BDNF protein and mRNA in the entire neuronal network of intact spinal cord. The questions arise: (i) how the treadmill locomotor training, supplemented with tail stimulation, affects the expression of molecular correlates of synaptic plasticity in spinal rats, and (ii) if a response is related to BDNF protein level and distribution. We investigated the effect of training in rats spinalized at low thoracic segments on the level and distribution of BDNF immunoreactivity (IR) in ventral quadrants of the lumbar segments, in conjunction with markers of presynaptic terminals, synaptophysin and synaptic zinc. RESULTS: Training improved hindlimb stepping in spinal animals evaluated with modified Basso-Beattie-Bresnahan scale. Grades of spinal trained animals ranged between 5 and 11, whereas those of spinal were between 2 and 4. Functional improvement was associated with changes in presynaptic markers and BDNF distribution. Six weeks after transection, synaptophysin IR was reduced by 18% around the large neurons of lamina IX and training elevated its expression by over 30%. The level of synaptic zinc staining in the ventral horn was unaltered, whereas in ventral funiculi it was decreased by 26% postlesion and tended to normalize after the training. Overall BDNF IR levels in the ventral horn, which were higher by 22% postlesion, were unchanged after the training. However, training modified distribution of BDNF in the processes with its predominance in the longer and thicker ones. It also caused selective up-regulation of BDNF in two classes of cells (soma ranging between 100-400 microm2 and over 1000 microm2) of the ventrolateral and laterodorsal motor nuclei. CONCLUSION: Our results show that it is not BDNF deficit that determines lack of functional improvement in spinal animals. They indicate selectivity of up-regulation of BDNF in distinct subpopulations of cells in the motor nuclei which leads to changes of innervation targeting motoneurons, tuned up by locomotor activity as indicated by a region-specific increase of presynaptic markers.

Parvalbumin-containing neurons, perineuronal nets and experience-dependent plasticity in murine barrel cortex.

The ability to undergo experience-dependent plasticity in the neocortex is often limited to early development, but also to particular cortical loci and specific experience. In layers II-IV of the barrel cortex, plasticity evoked by removing all but one vibrissae (univibrissa rearing) does not have a time limit except for layer IV barrels, where it can only be induced during the first postnatal week. In contrast, deprivation of every second vibrissa (chessboard deprivation) removes time limits for plasticity. The mechanism permitting plasticity in response to chessboard deprivation and halting it in reply to univibrissa rearing is unknown. Condensation of chondroitin sulfate proteoglycans into perineuronal nets and an increase in intracortical inhibition mediated by parvalbumin-containing interneurons are implicated in closing the critical period for ocular dominance plasticity. These factors could also be involved in setting up the critical period in barrels in a way that depends on a particular sensory experience. We therefore examined changes in density of parvalbumin-containing cells and perineuronal nets during development of mouse barrel cortex and after brief univibrissa and chessboard experience in adolescence. We observed a progressive increase in the density of the two markers across cortical layers between postnatal day 10 and 20, which was especially pronounced in the barrels. Univibrissa rearing, but not chessboard deprivation, increased the density of perineuronal nets and parvalbumin-containing cells in the deprived barrels, but only those that immediately neighbour the undeprived barrel. These data suggest the involvement of both tested factors in closing the critical period in barrels in an experience-dependent manner.

Spatiotemporal dynamics of astroglial and microglial responses after photothrombotic stroke in the rat brain.

The effects of photothrombotic stroke in primary somatosensory cortex on astroglial and microglial activation in various regions of lesioned brain were examined at different time points, using immunohistochemistry and lectin binding. The increase in GFAP expression was observed exclusively in the ipsilateral hemisphere, both in the perilesional area and cortical regions distant from the infarct. This remote increase was detectable up to sixty days after the infarct. Transient GFAP elevation was also found in the hippocampus one day after photothrombosis, whereas it was more prolonged in amygdala, as demonstrated at four days after lesion. In contrast to a widespread astrocytic activation, the microglial response was shortlasting and local, confined to lesion and perilesional area. Widespread and prolonged activation of astrocytes after stroke may provide factors promoting slowly developing recovery processes in the whole brain, while microglial response seems to be involved in local repair and removal of cellular debris.

[Ionotropic glutamate receptor trafficking--there and back again]. / Wedrówki receptorów jonotropowych--do synapsy i z powrotem.

Glutamate is a major excitatory neurotransmitter in brain. It engages mainly ionotropic glutamate receptors of AMPA and NMDA type. Thus, regulation of the number and properties of the receptors is crucial for correct neuronal communication, but also contributes to various forms of synaptic plasticity, namely neuronal development, learning and memory. Glutamate receptors are not static components of synapses. On the contrary, they are continuously delivered and removed from postsynaptic membranes and this process is regulated by synaptic activity, Receptor trafficking to synapses is a multi-step process, involving exit from endoplasmic reticulum, transport along dendrites, incorporation to postsynaptic membrane and finally removing them from synapses. The transport is regulated by numerous proteins, especially those bearing PDZ domains, or by receptors themselves.

Dissociation of synaptic zinc level and zinc transporter 3 expression during postnatal development and after sensory deprivation in the barrel cortex of mice.

In the neocortex, synaptic zinc level is regulated by sensory experience. Previously, we found that trimming of mystacial vibrissae resulted in an increase of synaptic zinc level in corresponding deprived barrels in the cortex of mice. The present study focused on the relationship between synaptic zinc and zinc transporter 3 (ZnT3) protein expression in the barrel cortex of mice during postnatal development and after sensory deprivation of selected vibrissae. Using immunocytochemistry and western blot analysis, we found that ZnT3 expression is delayed as compared with the onset of synaptic zinc and presynaptic markers, such as synapsin I and synaptophysin. Further, neither long-term deprivation in young mice nor short deprivation in adult mice, that resulted in an increase of synaptic zinc level, produced alterations in ZnT3, synapsin I or synaptophysin expression in deprived barrels. These results suggest that in the barrel cortex ZnT3, synapsin I or synaptophysin are not determinant for the activity-dependent regulation of the synaptic zinc level.

A surface antigen delineating a subset of neurons in the primary somatosensory cortex of the mouse.

Synapsins are a family of proteins associated with synaptic vesicles that are widely used as markers of synaptic terminals. We decided to investigate synapsin I expression in the mouse primary somatosensory cortex (SI). Immunostaining experiments using a polyclonal antibody against C-terminal domain of synapsin Ia/b (anti-SynI-C) showed an unusual pattern in the SI cortex compared to other regions of the neocortex. The staining delineated the cells located in barrel hollows. The immunoreactive product was located on the perikarya and proximal dendrites of gabaergic neurons found in layer IV and VI of the SI cortex. Other anti-synapsin antibodies did not reveal this pattern within the SI cortex, although in the hippocampus all antibodies examined produced a similar pattern of immunostaining. Deglycosylation of sections resulted in complete loss of immunodecoration on the cell perikarya. We suggest that the anti-SynI-C recognizes a saccharide surface epitope, possibly an element of perineuronal nets that is specific for the primary somatosensory cortex.

Chronic treatments with haloperidol and clozapine alter the level of NMDA-R1 mRNA in the rat brain: an in situ hybridization study.

The aim of the present study was to examine the influence of 3-month administration of the typical neuroleptic haloperidol (1 mg/kg/day) and the atypical one clozapine (30 mg/kg/day) on the expression of the NMDA-R1 mRNA in different brain structures using in situ hybridization in rats. A long-term treatment with haloperidol decreased the NMDA-R1 mRNA level in intermediate and caudal parts of the caudate-putamen and in more caudally localized regions of parietal and frontal cortices, but increased it in the CA1 region of the hippocampus. No significant changes in the nucleus accumbens, insular cortex, CA3 and dentate gyrus of the hippocampus were found after haloperidol administration. Clozapine did not influence the NMDA-R1 mRNA expression in the hippocampus, as well as in the intermediate and caudal regions of the caudate-putamen, but significantly increased it in the rostral region of the latter structure, in the nucleus accumbens and insular cortex. The present study suggests that both these neuroleptics influence the expression of the mRNA of the NMDA-R1 subunit in brain structures which are thought to be important for development of psychotic symptoms.