The application of tissue-engineered fish swim bladder vascular graft.

Small diameter (< 6 mm) prosthetic vascular grafts continue to show very low long-term patency, but bioengineered vascular grafts show promising results in preclinical experiments. To assess a new scaffold source, we tested the use of decellularized fish swim bladder as a vascular patch and tube in rats. Fresh goldfish (Carassius auratus) swim bladder was decellularized, coated with rapamycin and then formed into patches or tubes for implantation in vivo. The rapamycin-coated patches showed decreased neointimal thickness in both the aorta and inferior vena cava patch angioplasty models. Rapamycin-coated decellularized swim bladder tubes implanted into the aorta showed decreased neointimal thickness compared to uncoated tubes, as well as fewer macrophages. These data show that the fish swim bladder can be used as a scaffold source for tissue-engineering vascular patches or vessels.

Reactions of goldfish (Carassius auratus) to three suture patterns following full thickness skin incisions.

Three different suture patterns (simple interrupted, interrupted horizontal mattress, subcuticular) were placed in a full thickness incision (skin and body wall) of 18 goldfish (Carassius auratus). After 14 days all fish were euthanized using benzocaine solution. The tissue reactions were evaluated by gross visual inspection and histopathological examination. The superficial inflammatory reactions were graded on a scale from 0 (no inflammation) to 3 (severe inflammation). The inflammatory response in histological examination was graded on a scale from 0 (no inflammatory response or normal skin tissue) to 5 (severe inflammatory response and necrosis). The interrupted horizontal mattress induced a moderately severe to severe inflammatory response and necrosis (grades 4-5) but the subcuticular suture induced a very mild to mild inflammatory response (grades 0-1). The simple interrupted suture induced a moderate to moderately severe inflammatory response (grades 2-4). In conclusion, results showed that a subcuticular suture is the most appropriate to use in the closure of a full thickness body wall incision.

L-histidine reduces inhibitory avoidance in Carassius auratus submitted to cerebellar ablation.

The effect of post-training treatment with L-histidine (LH) on the memory consolidation of inhibitory avoidance was investigated in Carassius auratus submitted to cerebellar ablation. The inhibitory avoidance procedure included 3 days: one habituation day, one training day (5 trials, T1-T5) and one test day. On the training day, each fish was placed individually in a white compartment separated from a black compartment by a sliding door. When the fish crossed into the black compartment, a weight was dropped in front of it (aversive stimulus) and the time to cross was recorded. Saline or LH (100 mg/kg) was injected intraperitoneally 10 min after the trials. Data were log10 transformed and analyzed by ANOVA and the Student-Newman-Keuls test (P < 0.05). In T5, all groups [ablation/LH (N = 15; 189.60 +/- 32.52), ablation/saline (N = 14; 204.29 +/- 28.95), sham/LH (N = 14; 232.36 +/- 28.15), and sham/saline (N = 15; 249.07 +/- 25.82)] had similar latencies that were significantly higher than T1 latencies [ablation/LH (89.33 +/- 20.41), ablation/saline (97.00 +/- 25.16), sham/LH (73.86 +/- 18.42), and sham/saline (56.71 +/- 17.59)], suggesting acquisition of inhibitory avoidance. For the test, there was a significant reduction in latencies of ablation/LH (61.53 +/- 17.70) and sham/saline (52.79 +/- 25.37) groups compared to the ablation/saline (213.64 +/- 29.57) and sham/LH (199.43 +/- 24.48) groups, showing that cerebellum ablation facilitated retention of inhibitory avoidance and LH reversed the effect of ablation. The results support other evidence that LH impairs memory consolidation and/or reduces the interpretation of aversion value.

L-histidine reduces inhibitory avoidance in Carassius auratus submitted to cerebellar ablation

The effect of post-training treatment with L-histidine (LH) on the memory consolidation of inhibitory avoidance was investigated in Carassius auratus submitted to cerebellar ablation. The inhibitory avoidance procedure included 3 days: one habituation day, one training day (5 trials, T1-T5) and one test day. On the training day, each fish was placed individually in a white compartment separated from a black compartment by a sliding door. When the fish crossed into the black compartment, a weight was dropped in front of it (aversive stimulus) and the time to cross was recorded. Saline or LH (100 mg/kg) was injected intraperitoneally 10 min after the trials. Data were log10 transformed and analyzed by ANOVA and the Student-Newman-Keuls test (P < 0.05). In T5, all groups [ablation/LH (N = 15; 189.60 ± 32.52), ablation/saline (N = 14; 204.29 ± 28.95), sham/LH (N = 14; 232.36 ± 28.15), and sham/saline (N = 15; 249.07 ± 25.82)] had similar latencies that were significantly higher than T1 latencies [ablation/LH (89.33 ± 20.41), ablation/saline (97.00 ± 25.16), sham/LH (73.86 ± 18.42), and sham/saline (56.71 ± 17.59)], suggesting acquisition of inhibitory avoidance. For the test, there was a significant reduction in latencies of ablation/LH (61.53 ± 17.70) and sham/saline (52.79 ± 25.37) groups compared to the ablation/saline (213.64 ± 29.57) and sham/LH (199.43 ± 24.48) groups, showing that cerebellum ablation facilitated retention of inhibitory avoidance and LH reversed the effect of ablation. The results support other evidence that LH impairs memory consolidation and/or reduces the interpretation of aversion value.

Surgical removal of retrobulbar hemangioma in a goldfish (Carassius auratus).

The surgical removal of retrobulbar hemangioma is described in a mature fantail goldfish (Carassius auratus) with a 6-week history of a swollen right eye. The fish was anesthetized using alfaxalnone at a concentration in the water of 5 mg/L to facilitate fine-needle aspiration and surgical removal of the eye. The fish was treated with enrofloxacin 5 mg intraperitoneally and recovered with major buoyancy deficits that corrected 20 minutes after treatment with methadone at a dose of 0.4 mg intramuscularly. Histologic examination of the excised tissue demonstrated that the tumor was a compact hemangioma.

Early abrupt recovery from ataxia during vestibular compensation in goldfish.

1. Vestibular compensation was studied in goldfish that had had the utriculus and semicircular canal organs unilaterally removed. Characteristic postoperative behavioural deficits of postural asymmetry were quantitatively scored. Operated animals were compared with those subject to the same duration of anaesthesia and restraint during a sham operation. 2. The period of several minutes following the operation was characterized by severe postural asymmetry and locomotor ataxia. In the operated fish, but not the sham-operated ones, the eyes rolled tonically towards the operated side without nystagmus, the body was flexed towards the operated side, and any swimming was disoriented with rolling motion towards the operated side. These deficits lasted less than 30 min after revival from the anaesthesia. All three behavioral deficits ended abruptly within 1 min of each other for individual fish, and normal, nearly upright swimming was then maintained, even in the dark. 3. We interpret this recovery as one of the first stages in the central process of vestibular compensation. The unusually abrupt end of these deficits in adult goldfish compared with that in other vertebrates suggests a remarkable capacity for the central nervous system to adapt. The speed of recovery of three distinct motor outputs supports models of early compensation that utilize central modulation or gain control of existing pathways, rather than anatomical reorganization.

Postural changes occurring during one month of vestibular compensation in goldfish.

1. Postural behavioural changes during vestibular compensation were studied in goldfish. The tilting posture induced by directional light in the dorsal light reflex (DLR) was monitored by an automated camera system. Responses were measured over a 1-month period following a partial unilateral labyrinthectomy. 2. After the fish had recovered from the ataxic stage, the first observable DLR had shifted strongly towards the operated side. This early bias decreased rapidly, then more gradually. Mean values for the DLR reached a steady state within 2 weeks. 3. Recovery rates were slowest for DLR tilts elicited by light presented from the operated side. 4. The DLR did not recover to preoperative control values for light from either the intact or operated side. Shortly after the operation, light from the operated side produced DLR values nearly double the normal; light from the intact side had an effect very little different from normal. At steady state, the light effect from the operated side had decreased from the high immediately post-ataxic levels to a level roughly 1.5 times normal, but the light effect from the intact side had increased, also reaching a level roughly 1.5 times normal. Thus the final values again show symmetry. 5. Variability appears to be an important feature of the response.