using-an-automated-3d-tracking-system-to-record-individual-shoals

Using an Automated 3D-tracking System to Record Individual and Shoals of Adult Zebrafish

Like many aquatic animals, zebrafish (Danio rerio) moves in a 3D space. It is thus preferable to use a 3D recording system to study its behavior. The ...

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The optomotor response (OMR) is a simple experimental paradigm that is widely used in the study of visual system functions. In the current paper we investigated how spatial and temporal properties of repetitive stimuli determine the OMR in zebrafish. The experiments showed that the OMR has the temporal characteristic of a low-pass filter when the spatial frequencies are low and of a band-pass filter when the spatial frequencies are high. These findings are discussed on the basis of inherent sampling constraints of any motion detector. We found some indications that the strength and direction of the OMR vary with the spatio-temporal frequency of the stimulus pattern as has previously been described for other species.

Spatio-temporal frequency characteristics of the optomotor response in zebrafish.

Centrifugal innervation of the neural retina has been documented in many species. In zebrafish Danio rerio, the only so-far described centrifugal pathway originates from terminal nerve (TN) cell bodies that are located in the olfactory bulb. Most of the TN axons terminate in the forebrain and midbrain, but some project via the optic nerve to the neural retina, where they synapse onto dopaminergic interplexiform cells (DA-IPCs). While the anatomical pathway between the olfactory and visual organs has been described, it is unknown if and how olfactory signals influence visual system functions. We demonstrate here that olfactory input is involved in the modulation of visual sensitivity in zebrafish. As determined by a behavioral assay and by electroretinographic (ERG) recording, zebrafish visual sensitivity was increased upon presentation of amino acids as olfactory stimuli. This effect, however, was observed only in the early morning hours when zebrafish are least sensitive to light. The effect of olfactory input on vision was eliminated after lesion of the olfactory bulbs or after the destruction of DA-IPCs. Intraocular injections of a dopamine D(2) but not a D(1) receptor antagonist blocked the effect of olfactory input on visual sensitivity. Although we cannot exclude the involvement of other anatomical pathways, our data suggest that the TN and DA-IPCs are the prime candidates for olfactory modulation of visual sensitivity.

Olfactory input increases visual sensitivity in zebrafish: a possible function for the terminal nerve and dopaminergic interplexiform cells.

We describe a dominant mutation, night blindness d (nbd), that causes late-onset rod photoreceptor cell degeneration in zebrafish. The mutation was induced by treating male zebrafish with N-ethyl-N-nitrosourea (ENU). Visual sensitivity was tested using a behavioral assay based on a visually mediated escape response. At a young age, the heterozygous (nbd+/-) fish did not show any signs of night blindness or retinal degeneration. At 2 years, their behaviorally assessed visual sensitivity was decreased, albeit no alterations in the electroretinogram (ERG) were detected. Histology revealed that in the mutant retinas the rod photoreceptor cell outer segments (ROS) were thinned out. In homozygous larvae (nbd-/-), mass neural degeneration was detectable at about 2 days post fertilization (dpf). They died at an early age, usually no later than 8 dpf. In conclusion, nbd is a dominant mutation that causes late-onset night blindness with slow progression. However, nbd is not photoreceptor cell-specific, as becomes clear from the systemic dysfunctions of the homozygous larvae.

ENU-induced late-onset night blindness associated with rod photoreceptor cell degeneration in zebrafish.

We describe here the morphological and functional alterations of the retina of mutant zebrafish, night blindness c ( nbc ). The nbc mutant was isolated from the F1 generation of N -ethyl- N -nitrosourea mutagenized founders. Visual sensitivity of wildtype and heterozygous ( nbc (+/-)) mutant fish was determined using a behavioral assay based on visually mediated escape responses. Histology, immunocytochemistry, and electroretinography were used to study structural and functional changes of the outer retina. The behavioral visual response of nbc (+/-) mutants started to deteriorate at 12 months of age. Considerable variations existed between the extents of retinal degeneration of individual fish. In the most severe cases, both rod and cone outer segments were degenerated. In moderate cases, only rod outer segments were affected. Yet in other cases, no degeneration was detected. The retina of homozygous ( nbc (-/-)) larvae had a normal appearance. However, they develop abnormally and died before 9 days post fertilization. In conclusion, nbc causes late-onset and progressive dominant retinal degeneration of both rod and cone photoreceptor cells. However, nbc is not a retina-specific gene, as the homozygous fish displayed extra-retinal defects.

Slow-progressing photoreceptor cell degeneration in night blindness c mutant zebrafish.

Dopamine (DA) is an important neuromodulator in the visual system. The release of DA in the retina largely depends on environmental lighting conditions. Most previous studies have assessed the effect of illumination on retinal DA or its metabolites using homogenates or in vitro preparations. This study was designed to investigate the effect of transitions between lighting conditions--from dark to steady or flickering light and vice versa--on retinal DA release in zebrafish using in vivo microdialysis. The transition from dark to flickering light increased DA release, whereas the transition from flickering light to dark decreased it. This latter effect depended on time of day within the light period, e.g., it was strongest in the late afternoon. When using steady light, none of these effects were seen. Our study also demonstrates that in vivo microdialysis can successfully be applied to the investigation of retinal DA release in zebrafish.

An in vivo microdialysis study of light/dark-modulation of vitreal dopamine release in zebrafish.

Here we report three dominant nightblindness mutations in zebrafish: nightblindness e (nbe), nightblindness f (nbf) and nightblindness g (nbg). The mutants were isolated in the F1 generation of N-ethyl-N-nitrosourea (ENU) mutagenized zebrafish using a behavioral assay based on visually mediated escape responses. Subsequently, electroretinographic (ERG) recordings were made, and histological sections were screened for degenerative processes. For each mutant line, correlation analysis between behavioral, ERG and histological parameters was performed, and their relationships were determined by either calculating the Pearson correlation coefficient or by ANOVA. nbe is characterized by severe rod outer segments (ROS) degeneration. The degeneration correlates weakly with behavioral threshold and ERG b-wave amplitude, however, behavioral threshold correlates strongly with ERG b-wave. nbf is characterized by a dual histological pathology: patchy ROS-degeneration and 'gaps' homogeneously distributed over the outer nuclei layer (ONL) and between cone outer segments (COS). The correlations between histological pathology and behavioral threshold, and between behavioral threshold and ERG b-wave amplitude are obvious, but the correlation between histology and b-wave amplitude is less prominent. nbg is characterized by moderate ROS degeneration and moderate correlation between histology and behavioral threshold. Interestingly, behavioral threshold correlated inversely with ERG b-wave amplitude and threshold. Thus, contrary to what is normally seen in other nightblindness mutants, in nbg, the fish with the lowest behavioral threshold had the smallest b-waves amplitudes and the highest b-wave threshold. In our interpretation, the major impairment in nbe is photoreceptor-specific. In nbf, both photoreceptor degeneration and altered post-photoreceptor signaling are responsible for the behavioral deficit. In nbg, we find hypersensitivity at a post-photoreceptoral level concurrently with behavioral impairment.

Behavioral screening for nightblindness mutants in zebrafish reveals three new loci that cause dominant photoreceptor cell degeneration.

The vertebrate retina receives centrifugal input from the brain. In zebrafish, the major centrifugal input originates in the terminal nerve (TN). TN cell bodies are located in the olfactory bulb and ventral telencephalon. The TN projects axons to the retina where they branch in the inner plexiform layer (IPL) and synapse onto several inner retinal cell types, including dopaminergic interplexiform cells (DA-IPCs). This olfactoretinal centrifugal input plays a role in modulating retinal ganglion cell (RGC) activity, probably via dopamine-mediated Ca2+ signalling pathways. Normally, dopamine inhibits RGC firing by decreasing the inward Ca2+ current. Olfactory stimulation with amino acids decreases dopamine release in the retina, thereby reducing dopaminergic inhibition of RGCs. This model of olfacto-visual integration was directly tested by recording single-unit RGC activity in response to olfactory stimulation in the presence or absence of dopamine receptor blockers. Stimulation of the olfactory neurones increased RGC activity. However, this effect diminished when the dopamine D1 receptors were pharmacologically blocked. In isolated RGCs, the application of dopamine or a dopamine D1 receptor agonist decreased voltage-activated Ca2+ current and lowered Ca2+ influx. Together, the data suggest that olfactory input has a modulatory effect on RGC firing, and that this effect is mediated by dopamine D1 receptor-coupled Ca2+ signalling pathways.

Olfactoretinal centrifugal input modulates zebrafish retinal ganglion cell activity: a possible role for dopamine-mediated Ca2+ signalling pathways.

&#x6210;&#x4EBA;&#x786C;&#x9AA8;&#x9C7C;&#x7C7B;&#x7684;&#x89C6;&#x7F51;&#x819C;&#x53EF;&#x4EE5;&#x91CD;&#x65B0;&#x751F;&#x6210;&#x795E;&#x7ECF;&#x5143;&#x635F;&#x4F24;&#x540E;&#x3002;&#x76EE;&#x524D;&#x7684;&#x7814;&#x7A76;&#x63D0;&#x4F9B;&#x4E86;&#x89C6;&#x7F51;&#x819C;&#x529F;&#x80FD;&#x5168;&#x518D;&#x751F;&#x7684;&#x6591;&#x9A6C;&#x9C7C;&#xFF0C;&#x8868;&#x8FBE;&#x5E8F;&#x5217;&#x6807;&#x7B7E;&#x7684;&#x6591;&#x9A6C;&#x9C7C;&#xFF0C;&#x7EC6;&#x80DE;&#x6BD2;&#x7D20;&#xFF0C;&#x773C;&#x5185;&#x7684;&#x6CE8;&#x5C04;&#x540E;&#x7684;&#x7B2C;&#x4E00;&#x4E2A;&#x6587;&#x6863;&#x54C7;&#x3002;&#x635F;&#x5931;&#x548C;&#x66F4;&#x6362;&#x7684;&#x53E0;&#x5C42;&#x89C6;&#x7F51;&#x819C;&#x7EC4;&#x7EC7;&#x76D1;&#x6D4B;&#x5206;&#x6790;&#x7EC6;&#x80DE;&#x6B7B;&#x4EA1;&#x4E0E;&#x7EC6;&#x80DE;&#x589E;&#x6B96;&#xFF0C;&#x800C;&#x7531;&#x89C6;&#x7F51;&#x819C;&#x7279;&#x5F02;&#x6027;&#x57FA;&#x56E0;&#x8868;&#x8FBE;&#x6A21;&#x5F0F;&#x7684;&#x5206;&#x6790;&#x3002;&#x65F6;&#x7A7A;&#x7684;&#x89C6;&#x7F51;&#x819C;&#x795E;&#x7ECF;&#x8282;&#x7EC6;&#x80DE; &#xFF08;&#x7814;&#x8D44;&#x5C40;) &#x518D;&#x751F;&#x8FC7;&#x7A0B;&#x4F7F;&#x7528;&#x9009;&#x62E9;&#x6027;&#x6807;&#x8BB0;&#xFF0C;&#x5176;&#x6B21;&#xFF0C;&#x53CA;&#x88AB;&#x53D1;&#x73B0;&#xFF0C;&#x5F88;&#x5927;&#x7A0B;&#x5EA6;&#x4E0A;&#x5BF9;&#x4E00;&#x4E2A;&#x66F4;&#x627C;&#x8981;&#x7684;&#x80DA;&#x80CE;&#x795E;&#x7ECF;&#x8282;&#x7EC6;&#x80DE;&#x795E;&#x7ECF;&#x53D1;&#x751F;&#xFF0C;&#x65F6;&#x7A7A;&#x8FC7;&#x7A0B;&#x65F7;&#x65E5;&#x6301;&#x4E45;&#x7684;&#x65F6;&#x95F4;&#x6846;&#x67B6;&#x3002;&#x4F46;&#x662F;&#xFF0C;&#x67D0;&#x4E9B;&#x795E;&#x7ECF;&#x8282;&#x7EC6;&#x80DE;&#x6807;&#x8BB0;&#x7269;&#x7684;&#x916A;&#x6C28;&#x9178;&#x4E0D;&#x6307;&#x51FA;&#x3002;&#x589E;&#x957F;&#x548C;&#x5BFB;&#x8DEF;&#x7684;&#x795E;&#x7ECF;&#x8282;&#x7EC6;&#x80DE;&#x8F74;&#x7A81;&#x5BF9;&#x89C6;&#x795E;&#x7ECF;&#x5934; (ONH) &#x6D4B;&#x91CF;&#x7684;&#x8BC4;&#x4EF7;&#xFF0C;&#x5E76;&#x6062;&#x590D;&#x6B63;&#x5E38; ONH &#x5927;&#x5C0F;&#x7684;&#x53D1;&#x73B0;&#x5230;&#x5BF9;&#x5E94;&#x7684;&#x89C6;&#x89C9;&#x4ECB;&#x5BFC;&#x7684;&#x4E24;&#x79CD;&#x884C;&#x4E3A;&#x7684;&#x6062;&#x590D;&#x65F6;&#x95F4;&#x3002;&#x7136;&#x800C;&#xFF0C;&#x4E00;&#x4E9B;&#x5F02;&#x5E38;&#x6307;&#x51FA;&#x4E86;&#xFF0C;&#x5305;&#x62EC;&#x667A;&#x4E50;&#xFF0C;&#x751F;&#x4EA7;&#x8FC7;&#x5269;&#x548C;&#x5FAA;&#x5E8F;&#x6E10;&#x8FDB;&#x7684;&#x8FC7;&#x5EA6;&#x751F;&#x957F;&#x7684; ONH &#x957F;&#x7684;&#x6062;&#x590D;&#x65F6;&#x95F4;&#x3002;&#x6574;&#x4E2A;&#x89C6;&#x7F51;&#x819C;&#x518D;&#x751F;&#x6B64;&#x6A21;&#x578B;&#x7CFB;&#x7EDF;&#x63D0;&#x4F9B;&#x4E86;&#x5185;&#x5BB9;&#x4E30;&#x5BCC;&#x7684;&#x518D;&#x751F;&#x8FC7;&#x7A0B;&#x7684;&#x89C6;&#x56FE;&#x3002;

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The retinas of adult teleost fish can regenerate neurons following injury. The current study provides the first documentation of functional whole retina regeneration in the zebrafish, Danio rerio, following intraocular injection of the cytotoxin, ouabain. Loss and replacement of laminated retinal tissue was monitored by analysis of cell death and cell proliferation, and by analysis of retina-specific gene expression patterns. The spatiotemporal process of retinal ganglion cell (RGC) regeneration was followed through the use of selective markers, and was found to largely recapitulate the spatiotemporal process of embryonic ganglion cell neurogenesis, over a more protracted time frame. However, the re-expression of some ganglion cell markers was not observed. The growth and pathfinding of ganglion cell axons was evaluated by measurement of the optic nerve head (ONH), and the restoration of normal ONH size was found to correspond to the time of recovery of two visually-mediated behaviors. However, some abnormalities were noted, including overproduction of RGCs, and progressive and excessive growth of the ONH at longer recovery times. This model system for whole-retina regeneration has provided an informative view of the regenerative process.

Ganglion cell regeneration following whole-retina destruction in zebrafish.

Les r&#xE9;tines de poissons t&#xE9;l&#xE9;ost&#xE9;ens adulte peut r&#xE9;g&#xE9;n&#xE9;rer les neurones apr&#xE8;s une l&#xE9;sion. La pr&#xE9;sente &#xE9;tude fournit la premi&#xE8;re documentation de la r&#xE9;g&#xE9;n&#xE9;ration r&#xE9;tine fonctionnelle tout dans le poisson-z&#xE8;bre, Danio rerio, suite &#xE0; l&#x26;#39;injection intra-oculaire de la cytotoxine, l&#x26;#39;ouaba&#xEF;ne. Perte et le remplacement du tissu r&#xE9;tinien feuillet&#xE9; a &#xE9;t&#xE9; suivi par une analyse de la mort cellulaire et la prolif&#xE9;ration cellulaire, et par l&#x26;#39;analyse de la r&#xE9;tine-sp&#xE9;cifiques profils d&#x26;#39;expression g&#xE9;nique. Le processus spatio-temporelle de la cellule ganglionnaire de la r&#xE9;tine (RGC) a &#xE9;t&#xE9; suivie de r&#xE9;g&#xE9;n&#xE9;ration gr&#xE2;ce &#xE0; l&#x26;#39;utilisation des marqueurs s&#xE9;lectifs, et a &#xE9;t&#xE9; retrouv&#xE9; en grande partie r&#xE9;capituler le processus spatio-temporelle de la neurogen&#xE8;se des cellules ganglionnaires embryonnaires, sur une p&#xE9;riode de temps plus longue. Cependant, la r&#xE9;-expression de certains marqueurs des cellules ganglionnaires n&#x26;#39;a pas &#xE9;t&#xE9; observ&#xE9;. La croissance et le pathfinding des axones des cellules ganglionnaires a &#xE9;t&#xE9; &#xE9;valu&#xE9;e par la mesure de la t&#xEA;te du nerf optique (TNO), et la restauration de la taille normale ONH a &#xE9;t&#xE9; trouv&#xE9; pour correspondre &#xE0; la p&#xE9;riode de reprise de deux comportements visuellement induites. Cependant, certaines anomalies ont &#xE9;t&#xE9; not&#xE9;es, y compris la surproduction des CGR, et la croissance progressive et excessive de l&#x26;#39;ONH au temps de r&#xE9;cup&#xE9;ration plus longues. Ce syst&#xE8;me mod&#xE8;le pour l&#x26;#39;ensemble de la r&#xE9;tine de r&#xE9;g&#xE9;n&#xE9;ration a fourni un point de vue instructif du processus de r&#xE9;g&#xE9;n&#xE9;ration.

La r&#xE9;g&#xE9;n&#xE9;ration des cellules ganglionnaires Apr&#xE8;s entier r&#xE9;tine destruction chez le poisson z&#xE8;bre

Die Netzhaut adulter teleost Fische k&ouml;nnen Neuronen nach Verletzung regenerieren. Die aktuelle Studie liefert die erste Dokumentation der funktionalen ganzen Netzhaut Regeneration in den Zebrafish Danio Rerio, intraokulare Injektion von das Antigen nach Strophanthin. Verlust und Ersatz von laminierten Netzhaut-Gewebe wurde &uuml;berwacht durch Analyse der Zelltod und Zellproliferation und durch Analyse der Netzhaut-spezifischen Genausdruck Muster. Der raumzeitliche Prozess der retinalen Ganglienzellen Zellregeneration (RGC) folgte durch selektive Marker und wurde gefunden, um weitgehend den raumzeitliche Prozess der embryonalen Ganglion Zelle Neurogenese, &uuml;ber eine mehr rekapitulieren Zeitrahmen langwierig. Jedoch wurde die Re-expression von einigen Ganglion Zelle Markierungen nicht beobachtet. Das Wachstum und die Bewegungsplanungs des Ganglion Zellen Axone wurde durch Messung des Sehnerven Kopfes (ONH) ausgewertet, und die Wiederherstellung der Normalgr&ouml;&szlig;e ONH wurde festgestellt, dass die Zeit der Verwertung von zwei optisch-vermittelte Verhaltensweisen entsprechen. Jedoch wurden einige Anomalien festgestellt, einschlie&szlig;lich &Uuml;berproduktion von Routinggruppenconnectors und progressive und &uuml;berm&auml;&szlig;ige Wachstum von der ONH bei l&auml;ngeren Recovery-Zeiten. Dieses Modellsystem f&uuml;r die gesamte Netzhaut Regeneration hat einen informativen Blick auf den regenerativen Prozess bereitgestellt.

Ganglion Zellregeneration nach Zerst&ouml;rung der gesamten Netzhaut im Zebrafisch.

Le retine dei pesci teleostei adulti possono rigenerare i neuroni a seguito di infortunio. Questo studio fornisce la prima documentazione di rigenerazione funzionale intera retina in zebrafish, Danio rerio, dopo iniezione intraoculare di citotossicit&agrave;, ouabaina. Perdita e la sostituzione del tessuto retinico laminato &egrave; stata monitorata mediante analisi di morte cellulare e la proliferazione cellulare e mediante l&#39;analisi dei modelli di espressione del gene specifico del retina. Il processo di rigenerazione cellulare (RGC) gangliari retiniche spatiotemporal fu seguito attraverso l&#39;uso di marcatori selettivi e fu trovato a ripassare in gran parte spatiotemporal processo di neurogenesi delle cellule gangliari embrionale, sopra un pi&ugrave; prolungato lasso di tempo. Tuttavia, la riespressione di alcuni marcatori di cellule gangliari non &egrave; stata osservata. La crescita e il pathfinding degli assoni delle cellule gangliari &egrave; stata valutata misurando la testa del nervo ottico (ONH), e il ripristino di normali dimensioni ONH &egrave; stato trovato a corrisponde al tempo di recupero di due comportamenti visivamente-mediata. Tuttavia, sono state notate alcune anomalie, tra cui una sovrapproduzione di RGCs e la crescita progressiva ed eccessiva dell&#39;ONH a tempi di recupero pi&ugrave; lunghi. Questo sistema di modello per la rigenerazione di tutta la retina ha fornito una vista informativa del processo rigenerativo.

Rigenerazione delle cellule gangliari dopo distruzione di tutta la retina nello zebrafish.

&#x5927;&#x4EBA;&#x306E;&#x786C;&#x9AA8;&#x9B5A;&#x9B5A;&#x306E;&#x7DB2;&#x819C;&#x306F;&#x3001;&#x50B7;&#x5BB3;&#x5F8C;&#x306E;&#x795E;&#x7D4C;&#x7D30;&#x80DE;&#x3092;&#x518D;&#x751F;&#x3059;&#x308B;&#x3053;&#x3068;&#x304C;&#x3067;&#x304D;&#x307E;&#x3059;&#x3002;&#x73FE;&#x5728;&#x306E;&#x7814;&#x7A76;&#x3067;&#x306F;&#x3001;&#x7D30;&#x80DE;&#x6BD2;&#x7D20;&#x3001;&#x30A6;&#x30A2;&#x30D0;&#x30A4;&#x30F3;&#x306E;&#x773C;&#x5185;&#x6CE8;&#x5C04;&#x5F8C;&#x306B;&#x3001;&#x30BC;&#x30D6;&#x30E9;&#x30D5;&#x30A3;&#x30C3;&#x30B7;&#x30E5;&#x3001;&#x30BC;&#x30D6;&#x30E9;&#x30D5;&#x30A3;&#x30C3;&#x30B7;&#x30E5;&#x3067;&#x6A5F;&#x80FD;&#x5168;&#x4F53;&#x306E;&#x7DB2;&#x819C;&#x518D;&#x751F;&#x306E;&#x6700;&#x521D;&#x306E;&#x30C9;&#x30AD;&#x30E5;&#x30E1;&#x30F3;&#x30C8;&#x3092;&#x63D0;&#x4F9B;&#x3057;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;&#x7A4D;&#x5C64;&#x7DB2;&#x819C;&#x7D44;&#x7E54;&#x306E;&#x640D;&#x5931;&#x3001;&#x4EA4;&#x63DB;&#x306F;&#x7D30;&#x80DE;&#x6B7B;&#x3068;&#x7D30;&#x80DE;&#x5897;&#x6B96;&#x306E;&#x89E3;&#x6790;&#x306B;&#x3088;&#x3063;&#x3066;&#x3001;&#x7DB2;&#x819C;&#x7279;&#x7570;&#x7684;&#x907A;&#x4F1D;&#x5B50;&#x767A;&#x73FE;&#x30D1;&#x30BF;&#x30FC;&#x30F3;&#x306E;&#x89E3;&#x6790;&#x306B;&#x3088;&#x3063;&#x3066;&#x30E2;&#x30CB;&#x30BF;&#x30FC;&#x3057;&#x305F;&#x3002;&#x7DB2;&#x819C;&#x795E;&#x7D4C;&#x7BC0;&#x7D30;&#x80DE;&#xFF08;RGC&#xFF09;&#x306E;&#x6642;&#x7A7A;&#x9593;&#x30D7;&#x30ED;&#x30BB;&#x30B9;&#x306F;&#x3001;&#x518D;&#x751F;&#x304C;&#x9078;&#x629E;&#x30DE;&#x30FC;&#x30AB;&#x30FC;&#x3092;&#x4F7F;&#x7528;&#x3057;&#x3066;&#x7D9A;&#x3044;&#x305F;&#x3001;&#x3068;&#x5927;&#x90E8;&#x5206;&#x306F;&#x3082;&#x3063;&#x3068;&#x9577;&#x5F15;&#x304F;&#x6642;&#x9593;&#x67A0;&#x3067;&#x3001;&#x80DA;&#x306E;&#x795E;&#x7D4C;&#x7BC0;&#x7D30;&#x80DE;&#x306E;&#x795E;&#x7D4C;&#x767A;&#x751F;&#x306E;&#x6642;&#x7A7A;&#x9593;&#x904E;&#x7A0B;&#x3092;&#x518D;&#x73FE;&#x3059;&#x308B;&#x3053;&#x3068;&#x304C;&#x5224;&#x660E;&#x3057;&#x305F;&#x3002;&#x3057;&#x304B;&#x3057;&#x3001;&#x3044;&#x304F;&#x3064;&#x304B;&#x306E;&#x795E;&#x7D4C;&#x7BC0;&#x7D30;&#x80DE;&#x30DE;&#x30FC;&#x30AB;&#x30FC;&#x306E;&#x518D;&#x767A;&#x73FE;&#x306F;&#x8A8D;&#x3081;&#x3089;&#x308C;&#x306A;&#x304B;&#x3063;&#x305F;&#x3002;&#x795E;&#x7D4C;&#x7BC0;&#x7D30;&#x80DE;&#x8EF8;&#x7D22;&#x306E;&#x6210;&#x9577;&#x3068;&#x7D4C;&#x8DEF;&#x63A2;&#x7D22;&#x306F;&#x3001;&#x8996;&#x795E;&#x7D4C;&#x4E73;&#x982D;&#xFF08;ONH&#xFF09;&#x306E;&#x6E2C;&#x5B9A;&#x306B;&#x3088;&#x3063;&#x3066;&#x8A55;&#x4FA1;&#x3055;&#x308C;&#x3001;&#x901A;&#x5E38;&#x306E;ONH&#x30B5;&#x30A4;&#x30BA;&#x306E;&#x5FA9;&#x5143;&#x306F;2&#x8996;&#x899A;&#x7684;&#x306B;&#x5A92;&#x4ECB;&#x884C;&#x52D5;&#x306E;&#x56DE;&#x5FA9;&#x306E;&#x6642;&#x9593;&#x306B;&#x5BFE;&#x5FDC;&#x3059;&#x308B;&#x3053;&#x3068;&#x304C;&#x5224;&#x660E;&#x3057;&#x305F;&#x3002;&#x3057;&#x304B;&#x3057;&#x3001;&#x3044;&#x304F;&#x3064;&#x304B;&#x306E;&#x7570;&#x5E38;&#x304C;RGC&#x306E;&#x904E;&#x5270;&#x7523;&#x751F;&#x3001;&#x304A;&#x3088;&#x3073;&#x3088;&#x308A;&#x9577;&#x3044;&#x56DE;&#x5FA9;&#x6642;&#x9593;&#x3067;ONH&#x306E;&#x9032;&#x884C;&#x3084;&#x904E;&#x5EA6;&#x306E;&#x6210;&#x9577;&#x3092;&#x542B;&#x3081;&#x3001;&#x8A8D;&#x3081;&#x3089;&#x308C;&#x305F;&#x3002;&#x5168;&#x4F53;&#x306E;&#x7DB2;&#x819C;&#x518D;&#x751F;&#x306E;&#x305F;&#x3081;&#x306E;&#x3053;&#x306E;&#x30E2;&#x30C7;&#x30EB;&#x30B7;&#x30B9;&#x30C6;&#x30E0;&#x306F;&#x3001;&#x518D;&#x751F;&#x30D7;&#x30ED;&#x30BB;&#x30B9;&#x306E;&#x6709;&#x76CA;&#x306A;&#x30D3;&#x30E5;&#x30FC;&#x3092;&#x63D0;&#x4F9B;&#x3057;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;

&#x30BC;&#x30D6;&#x30E9;&#x30D5;&#x30A3;&#x30C3;&#x30B7;&#x30E5;&#x306B;&#x304A;&#x3051;&#x308B;&#x795E;&#x7D4C;&#x7BC0;&#x7D30;&#x80DE;&#x306E;&#x518D;&#x751F;&#x306B;&#x7D9A;&#x3044;&#x3066;&#x5168;&#x4F53;&#x306E;&#x7DB2;&#x819C;&#x306E;&#x7834;&#x58CA;

&#xC131;&#xC778; teleost &#xBB3C;&#xACE0;&#xAE30;&#xC758; &#xB9DD;&#xB9C9; &#xC2E0;&#xACBD; &#xBD80;&#xC0C1; &#xB2E4;&#xC74C; &#xB2E4;&#xC2DC; &#xB9CC;&#xB4E4; &#xC218; &#xC788;&#xC2B5;&#xB2C8;&#xB2E4;. &#xD604;&#xC7AC; &#xC5F0;&#xAD6C; zebrafish Danio rerio, cytotoxin&#xC758; &#xC548; &#xAD6C;&#xB0B4; &#xC8FC;&#xC0AC;&#xB97C; &#xB2E4;&#xC74C;&#xC5D0; &#xC7AC;&#xC0DD; &#xAE30;&#xB2A5; &#xC804;&#xCCB4; &#xB9DD;&#xB9C9;&#xC758; &#xCCAB; &#xBC88;&#xC9F8; &#xBB38;&#xC11C;&#xB97C; &#xC81C;&#xACF5; ouabain. &#xC190;&#xC2E4; &#xBC0F; &#xC801; &#xCE35;&#xB41C; &#xB9DD;&#xB9C9; &#xC870;&#xC9C1; &#xAD50;&#xCCB4; &#xC138;&#xD3EC; &#xC99D;&#xC2DD;, &#xC138;&#xD3EC;&#xC758; &#xC8FD;&#xC74C;&#xC758; &#xBD84;&#xC11D; &#xBC0F; &#xB9DD;&#xB9C9; &#xAD00;&#xB828; &#xC720;&#xC804;&#xC790; &#xD45C;&#xD604; &#xD328;&#xD134; &#xBD84;&#xC11D; &#xD558; &#xC5EC; &#xBAA8;&#xB2C8;&#xD130;&#xB9C1; &#xD588;&#xC2B5;&#xB2C8;&#xB2E4;. Spatiotemporal &#xB9DD;&#xB9C9; &#xC2E0;&#xACBD; &#xC808; &#xC138;&#xD3EC; (RGC) &#xC7AC;&#xC0DD; &#xACFC;&#xC815; &#xC120;&#xD0DD; &#xB9C8;&#xCEE4;&#xB97C; &#xD1B5;&#xD574; &#xB4A4;&#xB97C; &#xC774;&#xC5C8;&#xB2E4; &#xACE0; &#xD06C;&#xAC8C; &#xB354; &#xC774;&#xC0C1; &#xBC30;&#xC544; &#xC2E0;&#xACBD; &#xC808;&#xC758; &#xC138;&#xD3EC; &#xC2E0;&#xC0DD; spatiotemporal &#xACFC;&#xC815; &#xC815;&#xB9AC;&#xB97C; &#xAE30;&#xAC04; &#xC5F0;&#xC7A5;&#xC73C;&#xB85C; &#xBC1D;&#xD600;&#xC84C;&#xB2E4;. &#xADF8;&#xB7EC;&#xB098;, &#xC77C;&#xBD80; &#xC2E0;&#xACBD; &#xC808;&#xC758; &#xC138;&#xD3EC; &#xB9C8;&#xCEE4; &#xD45C;&#xC815; &#xAD00;&#xCC30; &#xD558;&#xC9C0;&#xB294;. &#xC131;&#xC7A5; &#xC2E0;&#xACBD; &#xC808; &#xC138;&#xD3EC; &#xCD95; &#xC0AD;&#xC758; pathfinding &#xC2DC; &#xC2E0;&#xACBD; &#xBA38;&#xB9AC; (ONH)&#xC758; &#xCE21;&#xC815;&#xC5D0; &#xC758;&#xD574; &#xD3C9;&#xAC00; &#xB418;&#xC5C8;&#xB2E4; &#xACE0; &#xC815;&#xC0C1;&#xC801;&#xC778; ONH &#xD06C;&#xAE30;&#xC758; &#xBCF5;&#xC6D0; &#xB450; &#xC2DC;&#xAC01;-&#xC911;&#xC7AC; &#xB3D9;&#xC791;&#xC758; &#xD68C;&#xBCF5;&#xC758; &#xC2DC;&#xAC04;&#xC5D0; &#xD574;&#xB2F9; &#xD558; &#xCC3E;&#xC544;&#xB0C8;&#xB2E4;. &#xADF8;&#xB7EC;&#xB098; RGCs, &#xACFC;&#xC789; &#xBC0F; &#xAE34; &#xBCF5;&#xAD6C; &#xC2DC;&#xAC04;&#xC5D0;&#xB294; ONH&#xC758; &#xC9C4;&#xBCF4;&#xC801;&#xC774; &#xACE0; &#xACFC;&#xB3C4; &#xD55C; &#xC131;&#xC7A5;&#xC744; &#xD3EC;&#xD568; &#xD558; &#xC5EC; &#xBA87; &#xAC00;&#xC9C0; &#xC774;&#xC0C1;&#xC774; &#xC9C0;&#xC801; &#xD588;&#xB2E4;. &#xC804;&#xCCB4; &#xB9DD;&#xB9C9; &#xC911;&#xC0DD;&#xC744; &#xC704;&#xD55C; &#xBAA8;&#xB378; &#xC2DC;&#xC2A4;&#xD15C;&#xC774; &#xC7AC;&#xC0DD; &#xACFC;&#xC815;&#xC758; &#xC815;&#xBCF4; &#xBCF4;&#xAE30;&#xB97C; &#xC81C;&#xACF5; &#xD558;&#xACE0;&#xC788;&#xB2E4;.

Zebrafish&#xC758; &#xC804;&#xCCB4; &#xB9DD;&#xB9C9; &#xD30C;&#xAD34;&#xC5D0; &#xB530;&#xB77C; &#xC2E0;&#xACBD; &#xC138;&#xD3EC; &#xC7AC;&#xC0DD;.

Las retinas de los peces tele&#xF3;steos adulto puede regenerar neuronas despu&#xE9;s de una lesi&#xF3;n. El presente estudio proporciona la primera documentaci&#xF3;n de la regeneraci&#xF3;n funcional de la retina entera en el pez cebra, Danio rerio, despu&#xE9;s de la inyecci&#xF3;n intraocular de la citotoxina, ouaba&#xED;na. P&#xE9;rdida y sustituci&#xF3;n de tejido retinal laminado fue monitorizada por an&#xE1;lisis de la muerte celular y la proliferaci&#xF3;n celular, y por an&#xE1;lisis de la retina-espec&#xED;ficos patrones de expresi&#xF3;n g&#xE9;nica. El proceso espacio-temporal de las c&#xE9;lulas ganglionares de la retina (CGR) de la regeneraci&#xF3;n fue seguida a trav&#xE9;s del uso de marcadores selectivos, y se encontr&#xF3; que recapitulan en gran medida el proceso espacio-temporal de la neurog&#xE9;nesis embrionaria de c&#xE9;lulas ganglionares, durante un per&#xED;odo de tiempo m&#xE1;s prolongado. Sin embargo, la re-expresi&#xF3;n de algunos marcadores de c&#xE9;lulas ganglionares no se observ&#xF3;. El crecimiento y pathfinding de axones de las c&#xE9;lulas ganglionares se evalu&#xF3; mediante la medici&#xF3;n de la cabeza del nervio &#xF3;ptico (HNO), y la restauraci&#xF3;n de tama&#xF1;o normal de HNO se encontr&#xF3; que corresponden al tiempo de recuperaci&#xF3;n de dos comportamientos mediados por visualmente. Sin embargo, algunas anomal&#xED;as se observaron, incluyendo la sobreproducci&#xF3;n de CGR, y el crecimiento progresivo y excesivo de la HNO en los tiempos de recuperaci&#xF3;n m&#xE1;s largos. Este sistema modelo para la regeneraci&#xF3;n de toda la retina-han aportado una visi&#xF3;n informativa del proceso de regeneraci&#xF3;n.

La regeneraci&#xF3;n de las c&#xE9;lulas ganglionares en general despu&#xE9;s de la retina-la destrucci&#xF3;n en el pez cebra

Behavioral changes in zebrafish induced by acute administration of buspirone have been interpreted to be the result of reduced anxiety. The purpose of the current study was to determine whether the effects of short-term and mid-term habituation to an open field corroborated the anxiolytic hypothesis. We exposed single zebrafish for 60 min to 5 mgL buspirone and tested them twice, immediately after exposure and again 3.5 h later. Each session lasted 20 min. Distance from bottom of tank, velocity, duration freezing, distance from center and horizontal distribution, and preferred spatial location were analyzed with a 3-D tracking system. In the early session (starting at 10:30), 20 min habituation of control zebrafish only marginally increased distance from bottom, which was still 90% higher in zebrafish treated with buspirone. When extending the habituation to 3.5 h, the picture became more complex. Distance from bottom did not further increase in control zebrafish. More importantly, some signs of increased anxiety were present in the buspirone group, such as increased freezing, reduced velocity, and increased bottom-dwelling. However, analyzing data of individual fish excluded rebound anxiety as unlikely. The delayed effects might be drug side effects, such as motor impairment and/or dizziness. The immediate and the delayed effects of buspirone have the appearance to be unrelated.

The immediate and the delayed effects of buspirone on zebrafish (Danio rerio) in an open field test: a 3-D approach.

Understanding the different patterns of anxiety-like behavioral responses is of great interest for pharmacological and genetic research. Here we report the effects of 3.5-hr habituation, buspirone and ethanol on those responses in shoaling zebrafish (Danio rerio). Since in these experiments we used a container with white walls, the effects of black-vs.-white walls were tested in a separate experiment. An important objective was to determine whether factors unrelated to anxiety played a role in modulating the responses. The anxiety-like behavioral responses studied here are social cohesion, distance from bottom and bottom-dwell time, radial distribution (to study thigmotaxis), transparent-wall preference (to study escape responses), locomotion and freezing. The experimental conditions yielded distinctly different response patterns. Thigmotaxis was the most obvious response to white walls and it was significantly reduced after 3.5-hr habituation. It was not affected by any of the drugs. The reduction of social cohesion after 3.5-hr habituation and in the 0.5% ethanol group was probably the most interesting effect seen in this study. A role of anxiety herein was suggested but could not be established with certainty. Other hypotheses were also discussed. The large increase of distance-from-bottom resulting in swimming close to the water surface, which occurred in both buspirone groups and in the 0.5%-ethanol group, is most likely not an anxiolytic response, because of the discrepancy with the in the literature well-established time-course and the absence of any effect of 3.5-hr habituation or black walls on vertical measures. Finally, locomotion and duration freezing could not be specifically taken as indicators for the state of anxiety and the results concerning transparent-wall preference were not sufficient clear. We conclude that the neuronal and ethological mechanisms underlying the effects of habituation, white-aversion, buspirone and ethanol on anxiety-like behavioral responses are complex and need further exploration.

Dissociating the effects of habituation, black walls, buspirone and ethanol on anxiety-like behavioral responses in shoaling zebrafish. A 3D approach to social behavior.

Because of its highly developed social character, zebrafish is a promising model system for the study of the genetic and neurochemical basis of altered social engagement such as is common in autism and schizophrenia. The traditional shoaling paradigm investigates social cohesion in homogeneous groups of zebrafish. However, the social dynamics of mixed groups is gaining interest from a therapeutic point of view and thus warrants animal modeling. Furthermore, mutant zebrafish are not always available in large numbers. Therefore, we developed a new paradigm that allows exploring shoaling in heterogeneous groups. The effects of MK-801, a non-competitive antagonist of the glutamate N-methyl-D-aspartate (NMDA) receptor, on social cohesion were studied to evaluate the paradigm. The drug has previously been shown to mimic aspects of autism and schizophrenia. Our results show that a single MK-801-treated zebrafish reduced social cohesion of the entire shoal drastically. Preliminary observations suggest that the social dynamics of the shoal as a whole was altered.

Hans Maaswinkel

R&D

xyZfish

Using an Automated 3D-tracking System to Record Individual and Shoals of Adult Zebrafish