Is Forced Swimming Immobility a Good Endpoint for Modeling Negative Symptoms of Schizophrenia? - Study of Sub-Anesthetic Ketamine Repeated Administration Effects

ABSTRACT Immobility time in the forced swimming has been described as analogous to emotional blunting or apathy and has been used for characterizing schizophrenia animal models. Several clinical studies support the use of NMDA receptor antagonists to model schizophrenia in rodents. Some works describe the effects of ketamine on immobility behavior but there is variability in the experimental design used leading to controversial results. In this study, we evaluated the effects of repeated administration of ketamine sub-anesthetic doses in forced swimming, locomotion in response to novelty and novel object recognition, aiming a broader evaluation of the usefulness of this experimental approach for modeling schizophrenia in mice. Ketamine (30 mg/kg/day i.p. for 14 days) induced a not persistent decrease in immobility time, detected 24h but not 72h after treatment. This same administration protocol induced a deficit in novel object recognition. No change was observed in mice locomotion. Our results confirm that repeated administration of sub-anesthetic doses of ketamine is useful in modeling schizophrenia-related behavioral changes in mice. However, the immobility time during forced swimming does not seem to be a good endpoint to evaluate the modeling of negative symptoms in NMDAR antagonist animal models of schizophrenia.

Three days of intermittent stretching after muscle disuse alters the proteins involved in force transmission in muscle fibers in weanling rats

The aim of this study was to determine the effects of intermittent passive manual stretching on various proteins involved in force transmission in skeletal muscle. Female Wistar weanling rats were randomly assigned to 5 groups: 2 control groups containing 21- and 30-day-old rats that received neither immobilization nor stretching, and 3 test groups that received 1) passive stretching over 3 days, 2) immobilization for 7 days and then passive stretching over 3 days, or 3) immobilization for 7 days. Maximal plantar flexion in the right hind limb was imposed, and the stretching protocol of 10 repetitions of 30 s stretches was applied. The soleus muscles were harvested and processed for HE and picrosirius staining; immunohistochemical analysis of collagen types I, III, IV, desmin, and vimentin; and immunofluorescence labeling of dystrophin and CD68. The numbers of desmin- and vimentin-positive cells were significantly decreased compared with those in the control following immobilization, regardless of whether stretching was applied (P<0.05). In addition, the semi-quantitative analysis showed that collagen type I was increased and type IV was decreased in the immobilized animals, regardless of whether the stretching protocol was applied. In conclusion, the largest changes in response to stretching were observed in muscles that had been previously immobilized, and the stretching protocol applied here did not mitigate the immobilization-induced muscle changes. Muscle disuse adversely affected several proteins involved in the transmission of forces between the intracellular and extracellular compartments. Thus, the 3-day rehabilitation period tested here did not provide sufficient time for the muscles to recover from the disuse maladaptations in animals undergoing postnatal development.

Efeitos morfológicos do retorno da sobrecarga após imobilização em alongamento de músculo esquelético de ratas / Morphological effects of resumption of loading after immobilization of skeletal muscles in lengthened position in female rats

CONTEXTUALIZAÇÃO: Na reabilitação, a imobilização em alongamento do músculo esquelético é realizada como contramedida para reverter efeitos de encurtamento muscular severo e em eventos pós-cirúrgicos. Acredita-se que o retorno às atividades funcionais normais estimule mecanotransdutores capazes de reorganizar a citoarquitetura normal muscular, porém a descrição das alterações histopatológicas relacionadas a esses procedimentos são escassas na literatura. OBJETIVOS: Avaliar e quantificar anomalias histológicas induzidas pela imobilização em alongamento do músculo EDL (Extensor Digitorum Longus) e confrontá-las com a livre movimentação do animal após esse procedimento. MÉTODOS: Foram utilizadas 18 ratas Wistar, distribuídas nos grupos: controle (GC); imobilizadas em flexão plantar (EDL em posição alongada) por 14 dias (GI); imobilizadas por 14 dias e liberadas por dez dias (GIL). Fragmentos do EDL foram congelados, seccionados e processados com reações imuno-histoquímica para colágenos I e III e histoquímica para Adenosina Trifosfatase Miofibrilar e Hematoxilina-Eosina. RESULTADOS: Os animais do GI apresentaram discreto aumento da expressão de colágeno I e de fibras em processo degenerativo/necrótico, redução da proporção de fibras tipo (FT) 2A e do diâmetro menor de todos os tipos de fibras, quando comparados com os animais do GC. Para o GIL, observou-se retorno da quantidade de colágeno I às condições controle, além de redução na proporção de FT2D, aumento do número de núcleos centralizados e do diâmetro menor das fibras quando comparadas com o GI, porém a expressão de FT2B e FT2D não atingiu os valores de referência. CONCLUSÕES: Os dados apresentados mostram que a retomada da função durante dez dias foi parcialmente eficiente na recuperação das características do músculo EDL após o período de imobilização e que, se extrapolados os dados à clínica fisioterapêutica, a adoção de procedimentos orientados às disfunções primárias do músculo pode favorecer a resposta morfofuncional do segmento e o seu íntegro restabelecimento.

BACKGROUND: In rehabilitation, immobilization of skeletal muscles in the elongated position is performed as a countermeasure in order to reverse the effects of severe muscle shortening and postoperative events. The return to normal functional activities is believed to stimulate mechanotransducers capable of reorganizing the normal muscle cytoarchitecture, but few data describing the histopathological changes relating to these procedures are available in the literature. OBJECTIVES: To assess and quantify histological abnormalities induced by immobilization of the extensor digitorum longus (EDL) muscle in elongation and to compare them with free movement of the animal after this procedure. METHODS: Eighteen female Wistar rats were used, divided into the following groups: Control; Immobilized in plantar flexion (EDL in an elongated position) for 14 days (GI); Immobilized for 14 days and released for 10 days (GIL). EDL fragments were frozen, sectioned and processed through immunohistochemical reactions for collagens I and III and histochemical methods for myofibrillar adenosine triphosphatase using hematoxylin-eosin. RESULTS: GI animals presented slight increases in collagen I and fiber expression in a degenerative/necrotic process, and reductions in the proportion of FT2A fibers and in the diameters of all fiber types, compared with the controls. In GIL, the quantity of collagen I returned to control conditions; the proportion of FT2D decreased; the number of centralized nuclei increased; and the fiber diameter was smaller than in GI. However, FT2B and FT2D expression did not reach the reference values. CONCLUSIONS: The data presented show that the recovery of function over a 10-day period was partially efficient with regard to recuperation of the characteristics of the EDL muscle after the period of immobilization. If the data are extrapolated to physiotherapeutic clinical practice, use of procedures directed towards primary dysfunctions of the muscle may favor a morphofunctional response in the segment and its full recovery.

Efeitos da corrida em esteira em músculos sóleos de ratos encurtados por imobilização / Effects of running on treadmill in soleus muscles of rats shortened by immobilization

O objetivo deste trabalho foi verificar as adaptações de peso e comprimento do músculo sóleo de ratos Wistar machos, além da estimativa do total de sarcômeros em série e comprimento médio dos sarcômeros, quando submetidos a um processo de remobilização em esteira. Foram utilizados 18 ratos (Wistar), divididos em três grupos: GC - músculo sóleo esquerdo (MSE) imobilizado e remobilizado solto; G10 - MSE imobilizado e remobilizado em velocidade de 10m/min; e G12 (n = 6) - MSE imobilizado e remobilizado em velocidade de 12m/min. Os resultados mostraram as seguintes variações, peso muscular: GC -22,35 por cento (p = 0,0089), G10 -12,52 por cento (p = 0,0623), G12 -12,07 por cento, (p = 0,0004); comprimento muscular: GC -5,47 por cento (p = 0,0120), G10 -3,31 por cento (p = 0,2868), G12 0,41 por cento (p = 0,8987); estimativa de sarcômeros em série: GC -15,42 por cento (p = 0,0047), G10 -10,87 por cento (p = 0,0193), G12 -4,97 (p = 0,2409); comprimento de sarcômeros GC 11,16 por cento (p = 0,0142), G10 9,31 por cento (p = 0,1270), G12 5,58 por cento (p = 0,1327). Conclui-se que G12 obteve maior eficácia após o período de imobilização, pois apresentou maior semelhança com o membro não imobilizado.

The aim of this work was to compare weight and length adaptations of the soleus muscle of male Wistar rats as well as estimation of the total number of serial sarcomere and mean sarcomere length, when they are submitted to remobilization on treadmill. 18 Wistar male rats were used and divided in the three following groups: CG - left soleus (LS) muscle immobilized and remobilized free in the cage; G10 - LS muscle immobilized and remobilized in speed of 10 m/min on treadmill; and G12 - LS muscle immobilized and remobilized in speed of 12 m/min. The right muscles (RS) of each animal were used for comparison. The results showed the following variations, muscular weigh: CG -22.35 percent (p = 0.0089), G10 -12.52 percent (p = 0.0623), G12 -12.07 percent, (p = 0.0004); muscle length: CG -5.47 percent (p = 0.0120), G10 -3.31 percent (p = 0.2868), G12 0.41 percent (p = 0.8987); estimation of number of serial sarcomere: CG -15.42 percent (p = 0.0047), G10 -10.87 percent (p = 0.0193), G12 -4.97 (p = 0.2409); sarcomere length: CG 11.16 percent, (p = 0.0142), G10 9.31 percent (p = 0.1270), G12 5.58 percent (p = 0.1327). It was concluded that G12 presented the best effectiveness after immobilization period since it presented greater similarity with the non-immobilized soleus.

Efeito do sulfato de vanadil sobre o comprometimento metabólico muscular induzido pela imobilização de membro posterior de ratos / Efecto del sulfato de vanadil sobre comprometimiento metabólico muscular inducido por la inmovilización del miembro posterior en ratones / Effect of the vanadyl sulphate on the muscular metabolic compromising induced by immobilization of posterior limb of rats

A proposta deste trabalho foi avaliar o efeito do sulfato de vanadil (SV) no perfil metabólico muscular de membro posterior imobilizado de ratos. Ratos Wistar foram divididos nos grupos (n = 6): controle (C), imobilizado em posição neutra do tornozelo (I), tratado com sulfato de vanadil (SV, 0,25mM, VO) e imobilizado tratado com SV (I + SV) durante sete dias. Após o período experimental, foram avaliadas as reservas de glicogênio (RG) dos músculos sóleo (S), gastrocnêmio branco (GB) e vermelho (GV), tibial anterior (TA) e extensor longo dos dedos (ELD), além do peso do S e ELD. A análise estatística foi realizada pela ANOVA seguida pelo teste de Tukey (p < 0,05). No grupo SV, os resultados mostraram elevação significativa nas RG (S 110 por cento, GB 71 por cento, GV 85 por cento, TA 125 por cento, EDL 108 por cento) e no peso (S 9 por cento, EDL 11 por cento). A imobilização reduziu significativamente as RG (S 31,6 por cento, GB 56,6 por cento, GV 39,1 por cento, ELD 41,7 por cento, TA 45,2 por cento) e peso (S 34,2 por cento e ELD 27 por cento); já no grupo I + SV, houve o aumento das RG em todos os músculos (S 211 por cento, GB 115 por cento, GV 148 por cento, ELD 161,9 por cento, TA 147 por cento), além de impedir a perda de peso do S (75 por cento) e ELD (46 por cento). O tratamento com sulfato de vanadil promoveu elevação nas reservas de glicogênio do grupo controle e imobilizado, além de impedir a perda de peso, demonstrando que seu efeito insulino-mimético é representado pela ação glicogênica associado a uma possível ação anticatabólica.

The purpose of this study was to evaluate the metabolic performance of immobilized skeletal muscle in rats treated with vanadyl sulphate. Male Wistar rats were divided in groups (n = 6): control (C), immobilized (I), treated with vanadyl sulphate (VS, 0,25 mM) and immobilized treated with vanadyl sulphate (I + VS) during seven days. The concentration of vanadyl sulphate diluted in water was 0,25 mM. After experimental stage, the glycogen content (GC) was evaluated in soleus (S), white gastrocnemius (WG), red gastrocnemius (RG), tibialis anterior (TA) and extensor digitorum longus (EDL) muscles, besides S and EDL weight. The statistical analysis was realized by the ANOVA followed by Tukey test (p < 0,05). In VS group, the results showed a significant increase in GC (S 110 percent, WG 71 percent, RG 85 percent, TA 125 percent, EDL 108 percent) and in the weight (S 9 percent, EDL 11 percent). The immobilization reduced significantly the GC (S 31.6 percent, WG 56.6 percent, RG 39.1 percent, EDL 41.7 percent, TA 45.2 percent) and weight (S 34.2 percent and ELD 27 percent), and in I + VS group, there was a increase of the GC in all muscles (S 211 percent, WG 115 percent, RG 148 percent, EDL 161.9 percent, TA 147 percent), besides hindering the weight loss in S (75 percent) and EDL (46 percent). The vanadyl sulphate treatment promoted an increase in the glycogen content of control and immobilized groups, besides hindering the weight loss, showing that the insulino-mimetic effect is represented by glycogenic action associate to a possible anti-catabolic action.

La propuesta de este trabajo ha sido la de evaluar el efecto del sulfato de vanadil (SV) en el perfil metabólico muscular de miembro posterior inmovilizado de ratones. Ratones Wistar fueron divididos en grupos (n = 6): control (C), inmovilizado en posición neutra de tobillo (I), tratado con sulfato de vanadil (SV, 0,25mM, VO) e inmovilizado tratado con SV (I + SV) durante 7 días. Después del periodo experimental, fueron evaluadas las reservas de glicógeno (RG) de los músculos soleo (S), gastrocnemio blanco (GB) y colorado (GV), tibial anterior (TA) y extensor largo de los dedos (ELD), además del peso de S y ELD. El análisis estadístico fue realizado por ANOVA seguido del test de Tukey (p < 0,05). En el grupo SV, los resultados mostraron elevación significativa en las RG (S 110 por ciento, GB 71 por ciento, GV 85 por ciento, TA 125 por ciento, EDL 108 por ciento) y en el peso (S 9 por ciento, EDL 11 por ciento). La inmovilización redujo significativamente las RG (S 31,6 por ciento, GB 56,6 por ciento, GV 39,1 por ciento, ELD 41,7 por ciento, TA 45,2 por ciento) y peso (S 34,2 por ciento e ELD 27 por ciento), por otro lado en el grupo I + SV, hubo aumento de las RG en todos los músculos (S 211 por ciento, GB 115 por ciento, GV 148 por ciento, ELD 161,9 por ciento, TA 147 por ciento), además de impedir la pérdida de peso de S (75 por ciento) y ELD (46 por ciento). El tratamiento con sulfato de vanadil promovió una elevación en las reservas de glicógeno del grupo control e inmovilizado, además de impedir la pérdida de peso, lo que demuestra que su efecto insulina mimético está representado por la acción glicogénica asociado a una posible acción anticatabólica.

Immobilization with Ketamine HCl and Tiletamine-Zolazepam in Cynomolgus Monkeys

To compare the effects of ketamine and tiletaminezolazepam (TZ) drugs widely used for the chemical restraint and immobilization of primates, on various physiological parameters and blood gas values in cynomolgus monkeys (Macaca facicularis). Rectal temperature, heart rate, respiration rate and blood gas analysis were measured before treatment and at 1, 10, 20, 30, 40, 50 and 60 min after administration. Additionally, in both groups, induction and maintenance times were compared. Heart rate, respiration rate, rectal temperature, pH and pCO2 were not significant different in the two groups. However, pO2 in the ketamine-treated group was significantly lower at 30 and 40 min than in the TZ-treated group. The induction time was short in both groups, and the maintenance time was longer in the TZ-treated group (67.8+/-6.5 min) than in the ketamine-treated group (42.3+/-6.7 min). However, decreased rectal temperatures must be watched and prevented following TZ administration to cynomolgus monkeys. It was considered that ketamine may be useful for short duration anesthesia including handling, physical examination, blood sampling and TZ may be useful for prolonged anesthesia including minor surgery and other surgical procedure.

Endogenous opiate analgesia induced by tonic immobility in guinea pigs

A function of the endogenous analgesic system is to prevent recuperative behaviors generated by tissue damage, thus preventing the emission of species-specific defensive behaviors. Activation of intrinsic nociception is fundamental for the maintenance of the behavioral strategy adopted. Tonic immobility (TI) is an inborn defensive behavior characterized by a temporary state of profound and reversible motor inhibition elicited by some forms of physical restraint. We studied the effect of TI behavior on nociception produced by the formalin and hot-plate tests in guinea pigs. The induction of TI produced a significant decrease in the number of flinches (18 + or - 6 and 2 + or - 1 in phases 1 and 2) and lickings (6 + or - 2 and 1 + or - 1 in phases 1 and 2) in the formalin test when compared with control (75 + or - 13 and 22 + or - 6 flinches in phases 1 and 2; 28 + or - 7 and 17 + or - 7 lickings in phases 1 and 2). In the hot-plate test our results also showed antinociceptive effects of TI, with an increase in the index of analgesia 30 and 45 min after the induction of TI (0.67 0.1 and 0.53 + or - 0.13, respectively) when compared with control (-0.10 + or - 0.08 at 30 min and -0.09 0.09 at 45 min). These effects were reversed by pretreatment with naloxone (1 mg/kg, ip), suggesting that the hypoalgesia observed after induction of TI behavior, as evaluated by the algesimetric formalin and hot-plate tests, is due to activation of endogenous analgesic mechanisms involving opioid synapses

Inmovilización prolongada / Prolonged immobilization

Ampliamente usado por muchos años para el manejo de traumatismo y enfermedades agudas, el reposo en cama y la inmovilización han sido estudiados en forma muy acabada durante las últimas décadas, demostrándose que los efectos perjudiciales de estos métodos terapéuticos superan, por gran margen, los efectos beneficiosos. Es así como se ha entendido que si bien la falta de actividad favorece la curación del órgano enfermo, igualmente causa un enorme deterioro en los órganos no afectados, comprometiendo no solo a un sistema corporal, sino prácticamente a todos los sistemas del organismo. Esta disfunción múltiple se conoce como desacondicionamiento y se compara como una entidad clínica separada y diferente del cuadro que le dió origen, conduciendo a complicaciones severas de difícil manejo y largo tratamiento. En el presente trabajo se revisan las causas que generan un estado de inmovilización prolongada, se describen sus principales efectos negativos y se entrega una visión de las acciones preventivas frente al tema

Glycerol production by immobilized mixed culture of TViride and S cerevisiae Y-1347

Calcium alginate as an entrapping gel at a 2% concentration attains higher bioconversion activities and glycerol yields [700 mg%] by immobilized mixed cultures of T. viride and S. cervisae y-1347. the entrapped mixed cultures could be repeatedly used in batch wise bioconversion successfully for at least six times as suspended in diluted nutrient medium. However, entrapped mixed cultures could be reused three times only when suspended in distilled water and must then be reactivated in nutrient medium to be reused

Participation of the periaqueductal gray matter in the modulation of tonic immobility in the guinea pig

Unilateral microinjection of carbachol (CCh, 1 microgram/0.2 microliter) into the specific sites in the ventral and ventrolateral portions of the periaqueductal gray (PAG) matter, which is known to be involved in analgesia, increases the duration of restraint-induced tonic immobility (TI) episodes induced in 23 adult male guinea pigs (Cavia porcellus). Mean duration of TI episodes was 107 +/- 16.38 s in the control group and increased to 220.7 +/- 40.24 s in the group microinjected with CCh. The potentiating effect of carbachol on TI duration was blocked by pretreatment with atropine (7.6 micrograms/0.4 microliter). These data suggest that PAG and the cholinergic system are involved in the modulation of the motor inhibition characteristic of TI which may be activated by the same stimuli that induce defensive analgesia.

Alteration of the motor response to an acute painful stimulus during tonic immobility

The motor responses caused by liminal (1.0 and 3.0 mA, applied for 3 s) and subliminal electrical stimuli (40 below the liminal value) applied to the dental pulp of the upper incisors of adult guinea pigs (N = 41) are more intense during tonic immobility (TI) than in control situations. Tonic immobility is a temporary state of profound motor inhibition elicited by some form of physical restraint in our experiment induced by maneuvers of lateral postural inversion and movement restraint. This suggests the occurrence of hyperalgesia in the trigeminal territory in situations of direct confrontation with a predator, as in the case for tonic immobility. This hyperalgesia may protect in a reflex manner vital regions of the head and neck from fatal bites inflicted by the predator, but without interrupting the state of immobility, since in our experiments the electric stimuli had no disruptive effect on TI episodes.

Fracturas diafisiarias del húmero: tratamiento funcional tipo Sarmiento / Fractures of the humeral shaft: Saramiento's functional treatment

El tratamiento funcional incruento con el método de Sarmiento para las fracturas diafisiarias del húmero, se basa en el comportamiento seudohidráulico de las partes blandas que rodean al hueso, lo cual promueve la osteogénesis y la consolidación. Es necesaria una vigilancia estrecha del aparato inmovilizador, con cambio o ajuste cada dos semanas. El uso de material plástico (Orthoplast) en la construcción del aparato funcional, simplifica su manejo. Se revisaron 40 casos de fracturas diafisiarias del húmero, tratados con este procedimiento, obteniéndose consolidasión en un 95 por ciento, con un promedio de inmovilización de 14.5 semanas, con reintegración a sus actividades en un período inferior a las 20 semanas. Hubo dos (5 por ciento) casos de seudoartrosis. En la evaluación final, 25(62.5 por ciento) casos fueron excelentes; buenos 11(27.5 por ciento); regulares dos (5 por ciento) y malos dos (5 por ciento).

Disruptive effect of the mesencephalic reticular formation on tonic immobility in guinea pigs

Cholinergic stimulation of the mesencephalic reticular formation with carbachol impairs the induction of tonic immobility (TI) by restreining maneuvers and reduces the duration of immobility episodes in guiena pigs TI which permits the animal to evaluate the best6 time for escape. It is possible that this monitoring inolves cirucits and neurotransmitters other than the ascending cholinergic system origination in the mesencephalic reticular formation