The function of the endocannabinoid system and glial cells in vivo in patients with first episode psychosis

Psychoses are relatively common and often severely debilitating mental disorders with a multifactorial etiological background involving both psychosocial and biological factors. Previously reported associations between the endocannabinoid and immune systems, and psychotic disorders, suggest that they are involved in the etiology of psychosis. Healthy individuals were studied with the selective type 1 endocannabinoid receptor (CB1R) radiotracer [18F]FMPEP-d2, and positron emission tomography (PET), for possible demographic confounders. Radiotracer synthesis and the compound’s behaviour in blood and brain tissues, were in line with reports from previous validation studies. Females had lower availabilities of CB1R than males in 17 discrete brain regions. Separate samples of male patients with first-episode psychosis (FEP) were then studied concurrently in Turku and London, using the CB1R radiotracers [18F]FMPEP-d2 and [11C]MEPPEP respectively. Lower CB1R availability was seen in FEP as compared to healthy controls. The availability of CB1R was also inversely associated with the symptomatology of the psychoses. Translocator protein (TSPO) expression has been postulated to represent glial cell and mitochondrial functions, both of which are influenced by endocannabinoid signalling. Another sample of male and female patients with first episode psychoses was studied using PET with the selective TSPO radiotracer [11C]PBR28. Male and female FEP subjects showed globally lower availability of brain TSPO in comparison to healthy controls. Two concurrent samples of FEP individuals showed persistent elevations of the chemokine CCL22 when compared to population controls. A subgroup of patients with the highest levels of CCL22 also had aberrant levels of other cyto- and chemokines. These results indicate that the immune and brain endocannabinoid systems have become dysregulated in early psychosis. Aberrant glial cell function and/or disturbances in cell metabolism are indicated by the lower availability of TSPO.Endokannabinoidijärjestelmän ja gliasolujen toiminta ensipsykooseissa Psykoosit ovat verrattain yleisiä, vakavia mielenterveyshäiriöitä, joiden syntyyn vaikuttaa sekä psykososiaaliset että biologiset tekijät. Endokannabinoidi- ja immuunijärjestelmien yhteydet psykooseihin, sekä dopamiinijärjestelmän toimintaan, viittaavat näiden järjestelmien toimivan osana psykoosien etiologiaa. Terveiden koehenkilöiden aivojen endokannabinoidijärjestelmän toimintaa tutkittiin tyypin 1 endokannabinoidireseptorin (CB1R) merkkiaineella [18F]FMPEPd2, ja positroniemissiotomografialla (PET), mahdollisten sekoittavien tekijöiden tunnistamiseksi. Merkkiaineen tuotannon laatua kuvaavat tunnusluvut, sekä merkkiaineen käyttäytyminen veressä ja aivokudoksessa, vastasivat aiempien validointitutkimusten tuloksia. Naiskoehenkilöillä oli alhaisemmat [18F]FMPEP-d2:n jakautumistilavuudet 17 aivoalueella verrattuna miehiin. Miespuolisten ensipsykoosipotilaiden aivojen endokannabinoidijärjestelmän toimintaa tutkittiin erikseen Turussa ja Lontoossa PET:lla vastaavasti CB1R merkkiaineilla [18F]FMPEP-d2 ja [11C]MEPPEP. Molempien otosten ensipsykoosipotilailla oli alhaisemmat merkkiaineiden jakautumistilavuudet verrattuna terveisiin koehenkilöihin. Merkkiaineen sitoutumiselle vapaat CB1R:t olivat lisäksi käänteisesti yhteydessä psykoosioireiden vaikeusasteeseen. Aivojen tukisolujen ja näiden mitokondrioiden toimintaan vaikuttavat sekä endokannabinoidiviestintä, että translokaattoriproteiinin (TSPO) toiminta. Ensipsykoosipotilailla oli kauttaaltaan alhaisemmat TSPO PET merkkiaineen [11C]PBR28 jakautumistilavuudet verrattuna terveisiin verrokkihenkilöihin. Ensipsykoosipotilaiden kemokiini CCL22:n pitoisuudet olivat verrokkien pitoisuuksia korkeammat. Korkeimpia CCL22:n pitoisuuksia omaavien potilaiden immuuniviestintä poikkesi muista verrokki- ja potilastutkittavista laaja-alaisesti. Nämä tulokset osoittavat, että immuuni- ja endokannabinoidijärjestelmät toimivat poikkeavasti ensipsykooseissa. TSPO:n poikkeava toiminta viittaa siihen, että aivojen tukisolut ja/tai solujen aineenvaihdunta häiriintyvät psykooseissa

Influence of galaxy stellar mass and observed wavelength on disc breaks in S4^4G, NIRS0S, and SDSS data

Breaks in the surface brightness profiles in the outer regions of galactic discs are thought to have formed by various internal and external processes, and by studying the breaks we aim to better understand what processes are responsible for the evolution of the outer discs. We use a large well-defined sample to study how common the breaks are, and whether their properties depend on galaxy stellar mass or observed wavelength. We study radial surface brightness profiles of 753 galaxies, obtained from the $3.6 \mu m$ images of the Spitzer Survey of Stellar Structure in Galaxies (S$^4$G), and the $K_s$-band data from the Near InfraRed S0-Sa galaxy Survey (NIRS0S), covering a wide range of galaxy morphologies and stellar masses. Optical SDSS or Liverpool telescope data was used for 480 of these galaxies. We find that in low-mass galaxies the single exponential discs (Type I) are most common, and that their fraction decreases with increasing galaxy stellar mass. The fraction of down-bending (Type II) discs increases with stellar mass, possibly due to more common occurrence of bar resonance structures. The up-bending (Type III) discs are also more common in massive galaxies. The observed wavelength affects the scalelength of the disc of every profile type. Especially the scalelength of the inner disc of Type II profiles increases from infrared to u-band on average by a factor of $\sim 2.2$. Consistent with the previous studies, we find that Type II outer disc scalelengths ($h_o$) in late-type and low-mass galaxies are shorter in bluer wavelengths, possibly due to stellar radial migration populating the outer discs with old stars. In Type III discs $h_o$ are larger in the u-band, hinting to the presence of young stellar population in the outer disc. While the observed wavelength affects the disc parameters, it does not significantly affect the profile type in our sample. (Abridged)Comment: 22 pages, 16 figures. Accepted for publication in Astronomy & Astrophysic

Kinematics and dynamics of the M51-type galaxy pair NGC 3893/96 (KPG 302)

We study the kinematics and dynamics of the M51-type interacting galaxy pair KPG 302 (NGC 3893/96). We analyse the distribution of the dark matter (DM) halo of the main galaxy in order to explore possible differences between DM halos of "isolated" galaxies and those of galaxies belonging to a pair. The velocity field of each galaxy was obtained using scanning Fabry-Perot interferometry. A two-dimensional kinematic and dynamical analysis of each galaxy and the pair as a whole is done emphasizing the contribution of circular and non-circular velocities. Non-circular motions can be traced on the rotation curves of each galaxy allowing us to differentiate between motions associated to particular features and motions that reflect the global mass distribution of the galaxy. For the main galaxy of the pair, NGC 3893, optical kinematic information is complemented with HI observations from the literature to build a multi-wavelength rotation curve. We try to fit this curve with a mass-distribution model using different DM halos. We find that the multi-wavelength rotation curve of NGC 3893, "cleaned" from the effect of non-circular motions, cannot be fitted neither by a pseudo-isothermal nor by a NFW DM halo.Comment: Accepted for publication in A&A. 11 pages, 9 figures and 2 table

Evidence for the concurrent growth of thick discs and central mass concentrations from S4^4G imaging

We have produced $3.6\mu{\rm m}+4.5\mu{\rm m}$ vertically integrated radial luminosity profiles of 69 edge-on galaxies from the Spitzer Survey of Stellar Structure in Galaxies (S$^4$G). We decomposed the luminosity profiles into a disc and a central mass concentration (CMC). These fits, combined with thin/thick disc decompositions from our previous studies, allow us to estimate the masses of the CMCs, the thick discs, and the thin discs ($\mathcal{M}_{\rm CMC}$, $\mathcal{M}_{\rm T}$, and $\mathcal{M}_{\rm T}$). We obtained atomic disc masses ($\mathcal{M}_{\rm g}$) from the literature. We then consider the CMC and the thick disc to be dynamically hot components and the thin disc and the gas disc to be dynamically cold components. We find that the ratio between the mass of the hot components and that of the cold components, $(\mathcal{M}_{\rm CMC}+\mathcal{M}_{\rm T})/(\mathcal{M}_{\rm t}+\mathcal{M}_{\rm g})$, does not depend on the total galaxy mass as described by circular velocities ($v_{\rm c}$). We also find that the higher the $v_{\rm c}$, the more concentrated the hot component of a galaxy. We suggest that our results are compatible with having CMCs and thick discs built in a short and early high star forming intensity phase. These components were born thick because of the large scale height of the turbulent gas disc in which they originated. Our results indicate that the ratio between the star forming rate in the former phase and that of the formation of the thin disc is of the order of 10, but the value depends on the duration of the high star forming intensity phase.Comment: Accepted for publication in A&

Comparison of bar strengths in active and non-active galaxies

Bar strengths are compared between active and non-active galaxies for a sample of 43 barred galaxies. The relative bar torques are determined using a new technique (Buta and Block 2001), where maximum tangential forces are calculated in the bar region, normalized to the axisymmetric radial force field. We use JHK images of the 2 Micron All Sky Survey. We show a first clear empirical indication that the ellipticies of bars are correlated with the non-axisymmetric forces in the bar regions. We found that nuclear activity appears preferentially in those early type galaxies in which the maximum bar torques are weak and appear at quite large distances from the galactic center. Most suprisingly the galaxies with the strongest bars are non-active. Our results imply that the bulges may be important for the onset of nuclear activity, but that the correlation between the nuclear activity and the early type galaxies is not straightforward.Comment: MNRAS macro in tex format, 9 pages, 10 figure

Bar-induced perturbation strengths of the galaxies in the Ohio State University Bright Galaxy Survey (OSUBGS) I

This paper presents bar strength measurements for a sample of 180 galaxies, based on the H-band images of the Ohio State University Bright Galaxy Survey (Eskridge et al. 2002, ApJS, 143, 73). We use a gravitational bar torque method, where the ratio of the maximum tangential force to the mean axisymmetric radial force is used as a quantitative measure of the bar strength. Based on our Fourier analysis we found that nearly 70 % of the galaxies classified as SAB-types in the near-IR might actually be non-barred systems. We also found that ovals are capable of inducing tangential forces at some level. The measurements of this study are used by Buta et al. (AJ, 127, 279) for the analysis of the distribution of bar strengths in spiral galaxies, and by Laurikainen et al. (ApJ, 607, 103) to study the connection between bar strength and nuclear activity.Comment: Monthly Notices, in press. 24 pages, 8 figure

Halpha Kinematics of S4G Spiral Galaxies - III. Inner rotation curves

We present a detailed study of the shape of the innermost part of the rotation curves of a sample of 29 nearby spiral galaxies, based on high angular and spectral resolution kinematic Halpha Fabry-Perot observations. In particular, we quantify the steepness of the rotation curve by measuring its slope dRvc(0). We explore the relationship between the inner slope and several galaxy parameters, such as stellar mass, maximum rotational velocity, central surface brightness ({\mu}0), bar strength and bulge-to-total ratio. Even with our limited dynamical range, we find a trend for low-mass galaxies to exhibit shallower rotation curve inner slopes than high-mass galaxies, whereas steep inner slopes are found exclusively in high-mass galaxies. This trend may arise from the relationship between the total stellar mass and the mass of the bulge, which are correlated among them. We find a correlation between the inner slope of the rotation curve and the morphological T-type, complementary to the scaling relation between dRvc(0) and {\mu}0 previously reported in the literature. Although we find that the inner slope increases with the Fourier amplitude A2 and decreases with the bar torque Qb, this may arise from the presence of the bulge implicit in both A2 and Qb. As previously noted in the literature, the more compact the mass in the central parts of a galaxy (more concretely, the presence of a bulge), the steeper the inner slopes. We conclude that the baryonic matter dominates the dynamics in the central parts of our sample galaxies.Comment: 11 pages, 11 figures, accepted for publication in MNRA

On the Link Between Central Black Holes, Bar Dynamics, and Dark Matter Halos in Spiral Galaxies

The discovery of a relationship between supermassive black hole (SMBH) mass and spiral arm pitch angle (P) is evidence that SMBHs are tied to the overall secular evolution of a galaxy. The discovery of SMBHs in late-type galaxies with little or no bulge suggests that an underlying correlation between the dark matter halo concentration and SMBH mass (MBH) exists, rather than between the bulge mass and MBH. In this paper we measure P using a two-dimensional fast fourier transform and estimate the bar pattern speeds of 40 barred spiral galaxies from the Carnegie-Irvine Galaxy Survey. The pattern speeds were derived by estimating the gravitational potentials of our galaxies from Ks-band images and using them to produce dynamical simulation models. The pattern speeds allow us to identify those galaxies with low central dark halo densities, or fast rotating bars, while P provides an estimate of MBH. We find that a wide range of MBH exists in galaxies with low central dark matter halo densities, which appears to support other theoretical results. We also find that galaxies with low central dark halo densities appear to follow more predictable trends in P versus de Vaucouleurs morphological type (T) and bar strength versus T than barred galaxies in general. The empirical relationship between MBH and total gravitational mass of a galaxy (Mtot) allows us to predict the minimum Mtot that will be observationally measured of our fast bar galaxies. These predictions will be investigated in a subsequent paper.Comment: 17 pages, 1 table, 11 figures, accepted for publication in MNRA

Extrapyramidal symptoms predict cognitive performance after first-episode psychosis

Publisher Copyright: © 2022, The Author(s).Extrapyramidal (EP) symptoms such as tremor, rigidity, and bradykinesia are common side effects of most antipsychotics, and may associate with impaired performance in neurocognitive testing. We studied EP symptoms in first-episode psychosis (FEP; n = 113). Cognitive testing and EP symptoms (three items of the Simpson-Angus Scale) were assessed at baseline and follow-up (mean follow-up time 12 months). Mild EP symptoms were present at treatment onset in 40% of the participants. EP symptoms were related with lower performance in neurocognitive testing at baseline and at follow-up, especially among those with nonaffective psychotic disorder, and especially in tasks requiring speed of processing. No associations between EP symptoms and social cognition were detected. In linear regression models, when positive and negative symptom levels and chlorpromazine equivalents were accounted for, baseline EP symptoms were associated with worse baseline global neurocognition and visuomotor performance. Baseline EP symptoms also longitudinally predicted global, verbal, and visuomotor cognition. However, there were no cross-sectional associations between EP symptoms and cognitive performance at follow-up. In sum, we found both cross-sectional and longitudinal associations between EP symptoms and neurocognitive task performance in the early course of psychosis. Those without EP symptoms at the start of treatment had higher baseline and follow-up neurocognitive performance. Even mild EP symptoms may represent early markers of long-term neurocognitive impairment.Peer reviewe