Effects of electroacupuncture on cardiac function and local field potential of sensory and motor cortices in mice with stress cardiomyopathy / 中国针灸

OBJECTIVE@#To observe the effects of electroacupuncture (EA) on cardiac function and local field potential (LFP) in sensory and motor cortices in mice with stress cardiomyopathy (SC), and to explore the possible mechanism of EA in improving SC.@*METHODS@#Twenty-seven female C57BL/6 mice were randomized into a blank group, a model group and an EA group, 9 mice in each group. In the model group and the EA group, SC model was established by continuous intraperitoneal injection of isoproterenol (ISO) for 14 days. At the same time of modeling, EA was applied at "Neiguan" (PC 6) and "Shenmen" (HT 7) in the EA group, with disperse-dense wave, in frequency of 2 Hz/15 Hz, 15 min each time, once a day for 14 days. After intervention, the total movement distance, the number of crossing grid and the number of crossing central grid of open field test within 5 minutes were observed; the left ventricular function indexes (left ventricular diameter of end-diastole [LVIDd], left ventricular diameter of end-systole [LVIDs], left ventricular volume of end-diastole [LVEDV], left ventricular volume of end-systole [LVESV], ejection fraction [EF] and fraction shortening [FS]) were detected by echocardiography; the changes in ST-segment amplitude and PR interval of electrocardiogram were observed; the morphology of myocardial tissue was observed by HE staining; the serum levels of cortisol (CORT), cardiac troponin T (cTnT) and brain natriuretic peptide (BNP) were detected by ELISA; the changes of LFP in sensory and motor cortices were recorded by Plexon multi-channel acquisition system.@*RESULTS@#Compared with the blank group, in the model group, the total movement distance, the number of crossing grid and the number of crossing central grid of open field test were decreased (P<0.05); LVIDd, LVIDs, LVEDV and LVESV were increased (P<0.05), EF and FS were decreased (P<0.05); ST-segment amplitude was increased (P<0.05) and PR interval was prolonged (P<0.05); irregular myocardial fiber arrangement, interstitial edema and inflammatory cell infiltration were observed; the serum levels of CORT, cTnT and BNP were increased (P<0.05); in the sensory cortex, the ratios of delta, theta, alpha and beta frequency bands were increased (P<0.05), the maximum energy spectrum of theta and beta frequency bands was increased (P<0.05), the power spectral density (PSD) of delta, theta, alpha, beta and gamma frequency bands was increased (P<0.05); in the motor cortex, the ratios of delta, theta, alpha and beta frequency bands were increased (P<0.05), the maximum energy spectrum as well as PSD of delta, theta, alpha, beta and gamma frequency bands were increased (P<0.05). Compared with model group, in the EA group, the total movement distance, the number of crossing grid and the number of crossing central grid of open field test were increased (P<0.05); LVIDd, LVIDs, LVEDV and LVESV were decreased (P<0.05), EF and FS were increased (P<0.05); ST-segment amplitude was decreased (P<0.05), and the PR interval was shortened (P<0.05); myocardial fiber injury and inflammatory cell infiltration were reduced; the serum levels of CORT, cTnT and BNP were decreased (P<0.05); in the sensory cortex, the ratios of theta, alpha and beta frequency bands were decreased (P<0.05), the ratio of gamma frequency band was increased (P<0.05), the maximum energy spectrum of theta frequency band as well as the PSD of theta, alpha, beta and gamma frequency bands were decreased (P<0.05); in the motor cortex, the ratios of theta, alpha and beta frequency bands were decreased (P<0.05) and the ratio of gamma frequency band was increased (P<0.05), the maximum energy spectrum of delta frequency band was increased (P<0.05), the maximum energy spectrum of theta frequency band as well as the PSD of theta and gamma frequency bands were decreased (P<0.05).@*CONCLUSION@#EA can improve cardiac function in mice with stress cardiomyopathy, and its mechanism may be related to the regulation of local field potentials in sensory and motor cortices.

Profound Hypothermia Provides Neuroprotection Following Hypothermic Circulatory Arrest: Ultrastructural Observations.

Objective: To assess whether cooling to 10°C can reduce neurological injury during 75 minutes of hypothermic circulatory arrest (HCA) compared to cooling to 18°C. Methods: Twelve domestic swine were used for this prospective blind randomized study. The animals were divided into 2 groups: Group A (n=6) underwent hypothermic circulatory arrest at 18oC for 75 min, and Group B (n=6) underwent hypothermic circulatory arrest at 10oC for 75 min. At the end of the experiment, the brains were removed and immersed in paraformaldehyde. All brains were dissected in the sagital plane. Tissue blocks from the left hemisphere were cut to encompass the sensory neocortex. Results: The selected area was identified with a dissecting microscope. Samples were examined in a blind fashion using electron microscope. Two investigators were instructed to find 10 representative neurons and analyze electron micrographs of these neurons for evidence of nuclear and cytoplasmic changes. Similarly, each investigator was instructed to examine the perinuclear neuronal mitochondria for abnormalities in mitochondrial distribution. Significant differences were observed between the 2 groups in mitochondria and rough endoplasmic reticulum (RER). In 5 of the 6 animals treated with 18oC HCA, neurons had slightly dilated RER, Golgi apparatus and mitochondria. In all 6 animals treated with 10oC HCA, the structure of the cytoplasmic organelles was intact, with no apparent dilatation (p=0.015). Conclusion: This study adds further support that hypothermia at 10oC exerts better cellular protection than hypothermia at 18oC, as evidenced by these electron microscopy findings.

Efecto de dosis única intraperitoneal de cipermetrina en la corteza cerebral somatosensorial de ratones CF- 1 / Effect of a single doses intraperitoneal of cypermethrin in brain somatosensory area of mice CF-1

La cipermetrina es un pesticida ampliamente utilizado en agricultura y en salud pública. Sus efectos histopatológicos a nivel de sistema nervioso central han sido poco estudiados, aún cuando se han demostrado casos de intoxicación en humanos, con importante compromiso neurológico. El propósito de este trabajo es conocer los efectos de una dosis única intraperitoneal de cipermetrina sobre la morfología neuronal de corteza somatosensorial (láminas superficiales y profundas) de ratones CF-1. 35 ratones fueron separados en tres grupos: control (n=5), control vehículo (n=15) y experimental (n=15); los dos últimos grupos sacrificados los días 1, 8, 18, 26 y 35, en grupos de a tres. Los encéfalos fueron removidos, fijados, y procesados con técnica de rutina, para un análisis morfométrico. Análisis estadístico con Kruskal Walli's test. Fueron evidenciadas alteraciones morfológicas correspondientes a muerte neuronal en todas las láminas estudiadas, a los distintos intervalos de tiempo.

The cypermethrin is a pesticide widely used in agriculture and public health. Their histopathological effects at central nervous system level, little have been studied, even though has demonstrated cases of poisoning in humans with important neurological commitment. The aim of this work is to know the effects a intraperitoneal single dose of cypermethrin on neuronal morphology of somatosensory cortex (superficial and deep laminae) of mice CF-1. 35 mice were separated in three groups: control (n=5), control vehicle (n=15) and experimental (n=15); the two last sacrificed groups 1, 8, 18, 26 and 35 days, three animals per group. The brain were removed, fixed, and process with routine technique, for a morphometric analysis. Statistical analysis with Kruskal Wallís test. We demonstrated corresponding morphologic alterations until death neuronal, in all studied laminae, at the different time intervals.

Dynamically Functional Reorganization inSomatosensory Cortex Induced byThe Contralateral Peripheral NerveTransfer to an Injured Arm / 生物化学与生物物理进展

Peripheral nerve injury of a limb usually causes functional reorganization of the contralateral somatosensory cortex.However, the patients with an operation of the contralateral seventh cervical nerve (C7) transfer to an injured arm with brachial plexusroot avulsions usually have the sole tactile sensibility of the healthy hand when the injured hand is touched at the early stage after theoperation. Then, at later stage they gradually get normal sense from the injured and the normal hands independently. Mimicked theprocess in a rat model based on the above operation, representations of the injured forepaw and the healthy forepaw in thesomatosensory cortex were studied by means of somatosensory evoked potential (SEP) recording. Somatosensory function shown inSEP response amplitude and peak latency of the injured forepaw gradually recovered with time after the operation due to thecontralateral C7 regeneration toward the injured limb, accompanied with the recovery process of limb movement. The somatosensoryrepresentation of the injured forepaw was observed exclusively in the ipsilateral somatosensory cortex since the 5th month after theoperation. Accordingly, the overlapped representation of the injured and healthy forepaws emerged in the ipsilateral somatosensorycortex of 13 rats studied except one with separated representation though the SEP latency and response amplitude were different inresponding to stimuli on the two forepaws. It is concluded that the contralateral peripheral nerve transfer to the injured arm can causedynamically functional reorganization in the ipsilateral somatosensory cortex suggesting a remarkable plasticity of the brain functioninduced by an alteration of sensory input between two sides of the body in adult rats.

Dynamically Functional Reorganization in Somatosensory Cortex Induced by The Contralateral Peripheral Nerve Transfer to an Injured Arm / 生物化学与生物物理进展

Peripheral nerve injury of a limb usually causes functional reorganization of the contralateral somatosensory cortex.However, the patients with an operation of the contralateral seventh cervical nerve (C7) transfer to an injured arm with brachial plexus root avulsions usually have the sole tactile sensibility of the healthy hand when the injured hand is touched at the early stage after the operation. Then, at later stage they gradually get normal sense from the injured and the normal hands independently. Mimicked the process in a rat model based on the above operation, representations of the injured forepaw and the healthy forepaw in the somatosensory cortex were studied by means of somatosensory evoked potential (SEP) recording. Somatosensory function shown in SEP response amplitude and peak latency of the injured forepaw gradually recovered with time after the operation due to the contralateral C7 regeneration toward the injured limb, accompanied with the recovery process of limb movement. The somatosensory representation of the injured forepaw was observed exclusively in the ipsilateral somatosensory cortex since the 5th month after the operation. Accordingly, the overlapped representation of the injured and healthy forepaws emerged in the ipsilateral somatosensory cortex of 13 rats studied except one with separated representation though the SEP latency and response amplitude were different in responding to stimuli on the two forepaws. It is concluded that the contralateral peripheral nerve transfer to the injured arm can cause dynamically functional reorganization in the ipsilateral somatosensory cortex suggesting a remarkable plasticity of the brain function induced by an alteration of sensory input between two sides of the body in adult rats.