Inducing sterile pyramidal neuronal death in mice to model distinct aspects of gray matter encephalitis

Up to one person in a population of 10,000 is diagnosed once in lifetime with an encephalitis, in 50–70% of unknown origin. Recognized causes amount to 20–50% viral infections. Approximately one third of affected subjects develops moderate and severe subsequent damage. Several neurotropic viruses can directly infect pyramidal neurons and induce neuronal death in cortex and hippocampus. The resulting encephalitic syndromes are frequently associated with cognitive deterioration and dementia, but involve numerous parallel and downstream cellular and molecular events that make the interpretation of direct consequences of sudden pyramidal neuronal loss difficult. This, however, would be pivotal for understanding how neuroinflammatory processes initiate the development of neurodegeneration, and thus for targeted prophylactic and therapeutic interventions. Here we utilized adult male NexCre‑ ERT2xRosa26-eGFP-DTA (= ‘DTA’) mice for the induction of a sterile encephalitis by diphtheria toxin-mediated ablation of cortical and hippocampal pyramidal neurons which also recruits immune cells into gray matter. We report multifaceted aftereffects of this defined process, including the expected pathology of classical hippocampal behaviors, evaluated in Morris water maze, but also of (pre)frontal circuit function, assessed by prepulse inhibition. Importantly, we modelled in encephalitis mice novel translationally relevant sequelae, namely altered social interaction/cognition, accompanied by compromised thermoreaction to social stimuli as convenient readout of parallel autonomic nervous system (dys)function. High resolution magnetic resonance imaging disclosed distinct abnormalities in brain dimensions, including cortical and hippocampal layering, as well as of cerebral blood flow and volume. Fluorescent tracer injection, immunohistochemistry and brain flow cytometry revealed persistent blood–brain-barrier perturbance and chronic brain inflammation. Surprisingly, blood flow cytometry showed no abnormalities in circulating major immune cell subsets and plasma high-mobility group box 1 (HMGB1) as proinflammatory marker remained unchanged. The present experimental work, analyzing multidimensional outcomes of direct pyramidal neuronal loss, will open new avenues for urgently needed encephalitis research

FIGURES 5–13 in Review of some mites (Acari: Laelapidae) associated with ants and bumblebees in Western Siberia, Russia

FIGURES 5–13. DIC micrographs of Cosmolaelaps dendrophilus, female. 5, idiosoma in dorsal view, enlarged section not to scale; 6, idiosoma in ventral view; 7, general view of some dorsal setae; 8, general view of setae Z5 and anal shield; 9, chelicera, fixed digit; 10, femur leg II; 11, femur leg III; 12, femur and trochanter leg IV; male. 13, chelicera.Published as part of Joharchi, Omid, Tolstikov, Andrei V., Khaustov, Alexander A., Khaustov, Vladimir A. & Sarcheshmeh, Mohammadhassan Abbasi, 2019, Review of some mites (Acari: Laelapidae) associated with ants and bumblebees in Western Siberia, Russia, pp. 71-92 in Zootaxa 4613 (1) on page 75, DOI: 10.11646/zootaxa.4613.1.3, http://zenodo.org/record/323807

Pneumolaelaps marginepilosa Sellnick

Pneumolaelaps marginepilosa (Sellnick) Figures 62–66. Specimens examined. Two females, RUSSIA, Tyumen Province, vicinity of lake Kuchak, 57°21’N, 66°03’E, 27 April and 06 September 2018 O. Joharchi coll., on Bombus sp. (Hymenoptera: Apidae). Notes. Pneumolaelaps marginepilosa was described from Iceland (Sellnick, 1940) where it was found on Bombus jonellus Kirby (Hymenoptera: Apidae). Bregetova (1977) and Karg (1993) considered that Pneumolaelaps marginalis is a junior synonym of Pneumolaelaps marginepilosa. Pneumolaelaps marginalis was described from Germanny (Willmann, 1953). It has been found on Bombus mucidus Gerstäcker (Hymenoptera: Apidae) (Willmann, 1953). This species widely distributed in Europe and Russia in association with bumblebees or their nests (Bregetova, 1977; Karg, 1993). In addition, Davydova & Nikolsky (1986) reported this species from Western Siberia on the basis of specimens collected on bumblebees. We have not had the opportunity to examine any specimens to confirm this identification. Our specimens agree well with the descriptions given by Sellnick (1940, Figs 86–95) and Evans & Till (1966, Fig. 34). The species is easily recognised by cells of reticulation of dorsal shield small, mostly as long as wide, dorsal shield setae j2, j3, z2–z4, s1–s4 and r2–r5 as long as j1, setae of opisthonotal area decreasing in length from anterior to posterior (Fig. 62), pre-sternal and sternal shields well separated, posterior margin of sternal shield strongly concave (Fig. 63), poststigmatal plate prominent, elongated triangular, genital shield elongate, rounded posteriorly, surface with irregular diagonal lines and polygonal cells (Fig. 63), anal shield nearly as long as wide (Fig. 63), hypostomal groove with six rows, each row with 3–12 denticles (Fig. 66). Opisthogastric cuticle and lateral margins densely hypertrichous, more than ten pairs of long setae in the area between genital and anal shield (Fig. 64).Published as part of Joharchi, Omid, Tolstikov, Andrei V., Khaustov, Alexander A., Khaustov, Vladimir A. & Sarcheshmeh, Mohammadhassan Abbasi, 2019, Review of some mites (Acari: Laelapidae) associated with ants and bumblebees in Western Siberia, Russia, pp. 71-92 in Zootaxa 4613 (1) on page 88, DOI: 10.11646/zootaxa.4613.1.3, http://zenodo.org/record/323807

Androlaelaps myrmecophilus

Androlaelaps myrmecophilus (Evans & Till) Figures 1–4. Androlaelaps casalis myrmecophila Evans & Till, 1966: 154. Androlaelaps myrmecophila.— Huhta & Karg, 2010: 334. Specimens examined. Four females, RUSSIA, Tyumen Province, vicinity of lake Kuchak, 57°21’N, 66°03’E, 27 April 2018, O. Joharchi coll., in the nest of Formica rufa L. (Hymenoptera: Formicidae), six females, RUSSIA, Tyumen Province, vicinity of lake Kuchak, 57°21’N, 66°03’E, 16 June 2016, A.A. Khaustov coll., in the nest of Formica pratensis Retzius (Hymenoptera: Formicidae). Notes. Androlaelaps myrmecophilus was described as a new subspecies of A. casalis (Berlese) from Great Britain (Evans & Till 1966). It has been found associated with Formica rufa L. (Hymenoptera: Formicidae). Huhta & Karg (2010) raised it to the species level and examined specimens from ants’ nests from Finland. Davydova & Nikolsky (1986) reported Androlaelaps aff. casalis from Western Siberia on the basis of specimens collected from the ants’ nests. We have not had the opportunity to examine any specimens to confirm this identification. A. myrmecophilus is now recorded in Western Siberia for the first time. Our specimen agrees very well with the description given by Evans & Till (1966, Fig. 11). This species most resembles A. casalis but differs from it by basally inflated pilus dentilis (Fig. 4) (vs. slender in A. casalis), smaller body size (Figs 1, 2) and setae Z5 obviously longer and thicker than all dorsal seate, with 2–4 minute barbs (Fig. 3) (vs. setae Z5 short, simple and the same thickness with the other dorsal setae in A. casalis).Published as part of Joharchi, Omid, Tolstikov, Andrei V., Khaustov, Alexander A., Khaustov, Vladimir A. & Sarcheshmeh, Mohammadhassan Abbasi, 2019, Review of some mites (Acari: Laelapidae) associated with ants and bumblebees in Western Siberia, Russia, pp. 71-92 in Zootaxa 4613 (1) on page 72, DOI: 10.11646/zootaxa.4613.1.3, http://zenodo.org/record/323807

FIGURES 26–34 in Review of some mites (Acari: Laelapidae) associated with ants and bumblebees in Western Siberia, Russia

FIGURES 26–34. DIC micrographs of Cosmolaelaps siberiensis sp. nov., female. 26, idiosoma in dorsal view; 27, idiosoma in ventral view; 28, general view of some dorsal setae, 29, genital and anal shields, general view of some opisthogastric setae; 30, genital and sternal shields; 31, epistome; 32, subcapitulum; 33, chelicera, fixed digit; 34, palp and apotel.Published as part of Joharchi, Omid, Tolstikov, Andrei V., Khaustov, Alexander A., Khaustov, Vladimir A. & Sarcheshmeh, Mohammadhassan Abbasi, 2019, Review of some mites (Acari: Laelapidae) associated with ants and bumblebees in Western Siberia, Russia, pp. 71-92 in Zootaxa 4613 (1) on page 79, DOI: 10.11646/zootaxa.4613.1.3, http://zenodo.org/record/323807