Laslo Puskas

Microvascular anatomy of the hippocampal formation

The hippocampal vessels were examined in 25 forebrain hemispheres injected with india ink or methylmethacrylate. There were two to seven hippocampal arteries, which measured 200-800 microns in diameter. The anterior hippocampal artery (AHA), which was present in 88.2% of the hemispheres, most often originated from the posterior cerebral and the anterior temporal arteries, that is, within the rostral hippocampo-parahippocampal arterial complex. It arose from the anterior choroidal artery in 29.4% of the hemispheres. The AHA extended between the uncus and the parahippocampal gyrus, and it supplied the head of the hippocampus. The middle hippocampal artery was constant. It most often arose from the posterior cerebral and the common temporal arteries. The middle hippocampal artery coursed just caudal to the uncus, in close relationship with the lateral posterior choroidal artery, and it usually supplied the middle part of the hippocampal formation. The posterior hippocampal artery, which existed in 94.1% of the hemispheres, most often arose from the posterior cerebral and the splenial arteries. It irrigated the caudal part of the hippocampal formation. The anastomoses connecting the posterior, middle, and the anterior hippocampal arteries were present in 29.4% of the hemispheres. The hippocampal arteries gave rise to the straight vessels, which divided into the large and the small intrahippocampal arteries. The highest density of the capillary network was noted in the pyramidal and molecular layers of the hippocampal formation. The clinical significance of the obtained microanatomical findings is discussed.

The thalamogeniculate perforators of the posterior cerebral artery: the microsurgical anatomy.

The thalamogeniculate (TG) arteries of 30 forebrain hemispheres were examined. These vessels varied from 2 to 12 in number (mean, 5.7), and from 70 to 580 microns in caliber (mean, 345.8 microns). The average caliber of all the TG vessels per posterior cerebral artery ranged from 700 to 3400 microns (mean, 1972 microns). The TG arteries most often originated as individual vessels; however, in 26.67% of the hemispheres examined they shared a common site of origin, and 33.33% of the hemispheres they arose from common stems. The common stems ranged from 320 to 800 microns in diameter (mean, 583 microns). The TG branches arose from the crural or ambient (P2) segment of the posterior cerebral artery in 80% of the hemispheres, from the P2 and the quadrigeminal (P3) segment in 20%, from both the distal segment of the posterior cerebral artery and the common temporal artery (13.33%), or from the distal segment and either the calcarine (3.33%) or parieto-occipital artery (3.33%). The TG arteries usually penetrated the medial geniculate body (100%), pulvinar thalami (80%), brachium of the superior colliculus (53.33%), or lateral geniculate body (13.33%). The collateral branches of the TG arteries were noted to reach the medial geniculate body (76.67%), pulvinar (70%), brachium of the superior colliculus (40%), crus cerebri (40%), and lateral geniculate body (6.67%). The anastomoses were present in 66.67%, usually between the TG vessels and the medial posterior choroidal artery (33.33%), or the mesencephalothalamic artery (26.67%). They ranged in number from 1 to 3 (mean, 1.2), and in caliber from 90 to 400 microns (mean, 197 microns).(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical significance of blood supply to the internal capsule and basal ganglia

Although the general vascular supply of the basal ganglia and internal capsule is well known, precise data are lacking regarding the variations of the vascular territories in the two regions. Twelve hemispheres were studied following an injection of coloured ink into the main cerebral arteries, namely the anterior cerebral (ACA), middle cerebral (MCA), anterior choroidal (AChA) and posterior cerebral artery (PCA). Serial sections of the injected hemispheres were taken in the axial or coronal plane. In 75% of the hemispheres, ACA perforators were seen to supply the inferomedial part of the head of the caudate nucleus and the anterior limb of the internal capsule, as well as the anterior and inferior portions of the putamen and globus pallidus. The MCA vessels perfused the superolateral part of the head and body of the caudate nucleus, the superior part of the entire internal capsule, most of the putamen and part of the globus pallidus. The AChA perforators perfused the medial segment of the globus pallidus, the inferior part of the posterior limb, the retrolenticular and sublenticular portions of the internal capsule, and occasionally its genu. The same segment of the globus pallidus and the inferior part of the genu of the internal capsule were most likely supplied by the perforators of the internal carotid artery. A predominance of ACA territory was noticed in one specimen (8.33%) and a predominance of MCA territory in two specimens (16.67%). The obtained anatomical data may help radiologic determination of perforators involved in ischemic events, as well as a better understanding of the neurological deficits in the same events.

Common features of the cerebral perforating arteries and their clinical significance

Dear Editor, I would like to thank Matthieu Delion and his colleagues for their compliments regarding our article [1]. At the same time, I am sorry for having not cited their valuable paper [2] on the insular branches of the middle cerebral artery. In general, there are some discrepancies in the terminology and definition of the insular and perforating branches. As we mentioned in our article, there are three main types of the branches of the cerebral arteries: the leptomeningeal, perforating and choroidal [3]. The superficial leptomeningeal vessels give rise to the penetrating branches, i.e. the cortical, subcortical and medullary twigs; the latter of which supply most of the white matter of the cerebral hemispheres, i.e. the centrum semiovale and the corona radiata [4]. On the other hand, the deep perforating vessels mainly originate from the basal cerebral arteries and supply the central hemispheric region, including the basal ganglia and the internal capsule. Accordingly, the mentioned long insular arteries, which arise from the M2 and M3 segments of the MCA, have nothing to do with the perforating vessels of the MCA from both the morphological aspect and the region of supply. These long insular vessels simply belong to the penetrating (medullary) twigs, which were not the subject of our article. As regards the short and medium-sized insular vessels, some of them can be classified as the Batypical^ perforators. However, we presented only the typical perforating arteries, i.e. those with certain common features, as was clearly described in our paper. For that reason, we did not mention the atypical perforators, such as those to the claustrum, the cerebellar roof nuclei and the hypothalamus. In any case, I am grateful to Delion and co-workers for their comment on our article, and for presenting the findings of their research.

Antidepressant effects of an inverse agonist selective for α5 GABA-A receptors in the rat forced swim test

Abstract It has been shown in electrophysiological studies that the ligand L-655,708 possesses a binding selectivity and a moderate inverse agonist functional selectivity for α5-containing GABA-A receptors. The present study is aimed to investigate the antidepressant effects of the ligand L-655,708 in the forced swim test (FST) and its impact on locomotor activity in rats. The behavior of the animals was recorded with a digital camera, and the data were analyzed by one-way ANOVA, followed by Dunnett’s test. In FST, L-655,708 significantly decreased immobility time at a dose of 3 mg/kg after a single and repeated administration (p<0.05), exerting acute and chronic antidepressant effects. However, it did not induce significant differences in the time of struggling behavior during FST. Furthermore, L-655,708 did not show a significant effect on locomotor activity (p>0.05). These data suggest that negative modulation at GABA-A receptors containing the α5 subunit may produce antidepressant effects in rats. These effects were not confounded by locomotor influences.

Profiling differences in chemical composition of brain structures using Raman spectroscopy.

Raman spectroscopy enables non-invasive investigation of chemical composition of biological tissues. Due to similar chemical composition, the analysis of Raman spectra of brain structures and assignment of their spectral features to chemical constituents presents a particular challenge. In this study we demonstrate that standard and independent component analysis of Raman spectra is capable of assessment of differences in chemical composition between functionally related gray and white matter structures. Our results show the ability of Raman spectroscopy to successfully depict variation in chemical composition between structurally similar and/or functionally connected brain structures. The observed differences were attributed to variations in content of proteins and lipids in these structures. Independent component analysis enabled separation of contributions of major constituents in spectra and revealed spectral signatures of low-concentration metabolites. This provided finding of discrepancies between structures of striatum as well as between white matter structures. Raman spectroscopy can provide information about variations in contents of major chemical constituents in brain structures, while the application of independent component analysis performed on obtained spectra can help in revealing minute differences between closely related brain structures.

NADPH oxidase and redox status in amygdala, hippocampus and cortex of male Wistar rats in an animal model of post-traumatic stress disorder

Abstract Post-traumatic stress disorder (PTSD) is a highly prevalent and impairing disorder. Oxidative stress is implicated in its pathogenesis. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is an important source of free radicals. The aim of the study was to assess oxidative stress parameters, activities of respiratory chain enzymes, and the expression of NADPH oxidase subunits (gp91phox, p22phox, and p67phox) in the single prolonged stress (SPS) animal model of PTSD. Twenty-four (12 controls; 12 subjected to SPS), 9-week-old, male Wistar rats were used. SPS included physical restraint, forced swimming, and ether exposure. The rats were euthanized seven days later. Cortex, hippocampus, amygdala, and thalamus were dissected. Malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), Complex I, and cytochrome C oxidase were measured using spectrophotometric methods, while the expression of NADPH oxidase subunits was determined by Western blot. Increased MDA and decreased GSH concentrations were found in the amygdala and hippocampus of the SPS rats. SOD activity was decreased in amygdala and GPx was decreased in hippocampus. Increased expression of the NADPH oxidase subunits was seen in amygdala, while mitochondrial respiratory chain enzyme expression was unchanged both in amygdala and hippocampus. In the cortex concentrations of MDA and GSH were unchanged despite increased Complex I and decreased GPx, while in the thalamus no change of any parameter was noticed. We conclude that oxidative stress is present in hippocampus and amygdala seven days after the SPS procedure. NADPH oxidase seems to be a main source of free radicals in the amygdala.

Cavum Septi Pellucidi as a Marker of the Neuropsychiatric Diseases: APointer or Mislead? A Cadaveric-Clinical Observation

Cavum Septi pellucid (CSP), a cavity between the laminae of the septum pellucidum, for a longer period has been reported as an anomaly of the brain midline, associated with neuropsychiatric diseases, mostly schizophrenia, but also posttraumatic stress disorder, De la Tourette disease, and persons who survived a repeated a serious head trauma, boxers on the first place. Our investigation has been performed on 479 unfixed frozen brains, of the autopsied individuals of both genders, and MRI scans of 250 examinees, out of which 110 had neuropsychiatric illness. In our sample, the prevalence of CSP was 22.96% among the autopsied individuals and 9.2% in examinees who underwent MRI scan. The cause of the death among schizophrenia suffering persons was suicide (18 out of 25 patients). Obviously, CSP is more frequently associated with neuropsychiatric diseases, but a dilemma still exists, did we make a bias in brain suitability for the examination or we did the same mistake in observing clinical cases. A large CSP, though, is an almost certain sign for an underlying neuropsychiatric impairment, especially schizophrenia. The CSP among alcoholics and persons with the priory sustained head blows is probably of the same cause and represents an aftermath of the diffuse axonal injuries, i.e. brain trauma.

Does the Strategy of Risk Group Testing for Hepatitis C Hit the Target

In the European Union, it is estimated that there are 5.5 million individuals with chronic infection of hepatitis C. Intravenous drug abuse is undoubtedly the key source of the hepatitis C epidemic in Europe and the most efficient mode of transmission of HCV infections (primarily due to short incubation time, but also because the virus is introduced directly into the blood stream with the infected needle). Potentially high-risk and vulnerable populations in Europe (and the world) include immigrants, prisoners, sex workers, men having sex with men, individuals infected with HIV, psychoactive substance users etc. Since there is a lack of direct evidence of clinical benefits of HCV testing, decisions related to testing are made based on indirect evidence. Clinical practice has shown that HCV antibody tests are mostly adequate for identification of HCV infection, but the problem is that this testing strategy does not hit the target. As a result of this health care system strategy, a large number of infected patients remain undetected or they are diagnosed late. There is only a vague link between screening and treatment outcomes since there is a lack of evidence on transmission risks, multiple causes, risk behavior, ways of reaching screening decisions, treatment efficiency, etc. According to results of limited number of studies it can be concluded that there is a need to develop targeted programmes for detection of HCV and other infections, but there also a need to decrease potential harms.

Phenotype of blood lymphocytes in correlation with histological picture in thyroid gland of rats treated with potassium iodide.

Having in mind the former results which confirmed the functional relationship between the thyroid and the immune system, and the administration of potassium iodide (KI) in the therapy of auto-immune diseases, we considered it of interest to investigate the pathogenesis of KI induced experimental thyroiditis, by studying the morphology of thymus, thyroid gland and spleen, as well as the phenotype of lymphocytes in the thymus and peripheral blood in relation to the expression of CD4 and CD8 molecules. The experiments have been carried out on 30 male Wistar rats, divided in 3 groups. The first group (n=10) received KI (225 μg/g, i.p.), the second group (n=10) received KI (675 μg/g, i.p.), while the third group (n=10) received sodium chloride (0.9%, i.p.). The intensity of histological lesions in the thyroid gland, was statistically significant (p<0.01) in KI treated groups, compared to the controls. KI also significantly decreased rat body mass, and increased masses of thymus and thyroid gland (p<0.05). No statistically significant difference was found in thymocyte and peripheral blood CD4+ and CD8+ subpopulation numbers between the groups. Our experiments suggest that KI, at least in some doses could induce mild lymphocytic thyroiditis in rats, and that this simple, practical and non-expensive model of experimental thyroiditis could be of importance for further research.