Ismael Jiménez Estrada

Center for Research and Advanced Studies of the National Polytechnic Institute | Cinvestav · Departamento de Fisiología, Biofísica y Neurociencias

Several types of sensory perception have circadian rhythms. The spinal cord can be considered a center for controlling circadian rhythms by changing clock gene expression. However, to date, it is not known if mechanonociception itself has a circadian rhythm. The hypothalamic A11 area represents the primary source of dopamine (DA) in the spinal cord...

To investigate whether mother and sibling interactions during the preweaning period influence the histological and electrophysiological characteristics of the sensory sural nerve (SUn) in the adult rat, litters composed of 1, 3, 6, 9, and 12 male pups (P) were formed and the pups routinely weighed until postnatal day 60 (PND60). At PND9, 3P and 6P...

The sural sensory nerve, which innervates the lower extremities, is a useful model for studying the structural and functional characteristics of peripheral sensory nerves. Its development and myelination extends across the early postnatal through to the juvenile stage. Myelination of the sural nerve depends on interactions between axons and Schwann...

Ferulic acid (FA) is a phytochemical with various bioactive properties. It has recently been proposed that due to its phytogenic action it can be used as an alternative growth promoter additive to synthetic compounds. The objective of the present study was to evaluate the growth performance, carcass traits, fiber characterization and skeletal muscl...

Background: Hyperactive heart fire syndrome is characterized by anxiety, insomnia, dream-disturbed sleep, tongue ulcers, heat in the hands, and palpitations. However, syndrome differentiation is often subjective due to a lack of objective, quantifiable variables. Objectives: To identify changes in heart rate variability (HRV) and psychometric analy...

FA dietary supplementation on the growth performance, carcass traits and histochemical characteristics of the Longissimus thoracis muscle from finishing pigs was investigated. Four hundred and twenty pigs were used in this study, and 105 animals (with five replicate pens and 21 pigs per pen) were assigned to one of four treatments: basal diet (BD)...

The purpose of this study was to analyze the light-dark variations in the concentrations of several neurotransmitters in the lumbar spinal cord of rats. Six groups of male Wistar rats were exposed to a 12 h light-12 h dark cycle for 70 days. At different time points of the experimental day (8, 12, 16, 20, 24 and 4 h), one of the groups of rats was...

Several studies have proposed that cocoa products-enriched in flavonoids reduce anxiety and depressive symptoms. (-)–Epicatechin (Epi), a flavonoid present in high concentration in cocoa, has been associated with many dark chocolate effects and has been postulated as an exercise mimetic. Physical exercise is used as an adjuvant treatment for many d...

Resumen Existen diferentes interpretaciones sobre el deqi descrito en los textos de la Medicina Tradicional China, lo que ha generado controversia en cuanto a lo que es o debería constituir el deqi. Con base en el estudio de los caracteres tradicionales y de las evidencias experimentales recientes, el presente artículo propone un concepto integrado...

Patients with degenerative diseases refer to feeling more pain during the night. However, it is unknown whether spinal nociception can be circadian and how is it controlled. We investigated whether the paw withdrawal threshold (PWT) could exhibit physiological circadian behavior as well as the contribution of the dopaminergic A11 nucleus and the sp...

Several experimental strategies have been developed in past years for the repair of damages evoked in axons, myelin, and motor functions by spinal cord injuries. This chapter briefly reviews some of such strategies. On the one hand, it examines individual procedures, such as: tissue or cell transplants (i.e. evolving cells of the olfactory glia or...

Fiber type composition, organization, and distribution are key elements in muscle functioning. These properties can be modified by intrinsic and/or extrinsic factors, such as undernutrition and injuries. Currently, there is no methodology to quantitatively analyze such modifications. On one hand, we propose a fractal approach to determine fiber typ...

The regenerative capability of the central nervous system is limited after traumatic spinal cord injury (SCI) due to intrinsic and extrinsic factors that inhibit spinal cord regeneration, resulting in deficient functional recovery. It has been shown that strategies, such as pre-degenerated peripheral nerve (PPN) grafts or the use of bone marrow str...

La acupuntura es un enfoque terapéutico que surgió de la medicina tradicional china. La Organización Mundial de la Salud recomienda el uso de la acupuntura para el tratamiento de una amplia variedad de enfermedades. La evidencia experimental sugiere que el mecanismo de trabajo de la acupuntura puede incluir la activación de múltiples sistemas regul...

Acupuncture is a therapeutic approach that emerged from traditional Chinese medicine. The World Health Organization recommends the use of acupuncture for the treatment of a wide variety of diseases. Experimental evidence suggests that the working mechanism of acupuncture may include the activation of multiple regulatory systems in the organism incl...

During the lactation period, rat pups are fed by the dam, and the patterns of mother-pup interaction change during this period. Additionally, there are changes in feeding; first, mother´s milk is the only food needed for sustenance, and later, it is combined with solid food and water. GH serum concentrations depend on both maternal-pup interaction...

Many functional diseases are related to dysautonomia, and heart rate variability has been used to assess dysautonomia. However, heart rate variability has not been studied in Spleen-Qi deficiency syndrome (SQDS). Healthy volunteers (n = 37) and patients with SQDS (n = 67), recruited from the Clinic of the State University of Ecatepec Valley were in...

In this study, the effect of low and high frequency electroacupuncture (EA) on the negative components of the spinal cord dorsum potentials (CDPs) generated by the electrical stimulation of the sural nerve was analyzed in diabetic rats induced by streptozotocin (STZ). Two groups of Wistar rats (120-150 gr) were used: one received STZ (60mg/kgi.p.)...

To understand the mechanisms of acupuncture is indispensable a multidisciplinary approach and the participation of several disciplines such as neurosciences, computers, cybernetics and systems theory. In the present article we propose a model called “biocircuits” that is constructed from the current evidence of the effect of acupuncture at the card...

Introduction: Women often develop pelvic floor dysfunction due to damage to the pelvic musculature during childbirth; however, the effect on pelvic floor nerves function is less understood. This study used adult rabbits to evaluate the electrophysiological and histological characteristics of the bulbospongiosus (Bsn) and pubococcygeus nerves (Pcn)...

Early adverse experiences disrupt brain development and behavior, but little is known about how such experiences impact on the development of the peripheral nervous system. Recently, we found alterations in the electrophysiological and histological characteristics of the sensory sural (SU) nerve in maternally-deprived, artificially-reared (AR) adul...

Resumen La neuromodulación por estimulación eléctrica del sistema nervioso constituye una novedosa estrategia terapéutica para mitigar el dolor crónico. Se ha mostrado que la electroacupuntura (EA) activa las fibras nerviosas de manera similar a la estimulación eléctrica directa de los nervios periféricos. La diferencia estriba en que la EA constit...

Aims: We analyzed the effect of multiparity on the fiber type composition of two skeletal muscles involved in the maintenance of the micturition process, the pelvic pubococcygeus (Pc) and perineal bulbospongiosus (Bs) muscles in nulliparous and multiparous rabbits (Oryctolagus cuniculus). Methods: We used the basic ATPase and NADH-TR techniques...

OBJECTIVE Chordoma is a slow-growing, locally aggressive cancer that is minimally responsive to conventional chemotherapy and radiotherapy and has high local recurrence rates after resection. Currently, there are no rodent models of spinal chordoma. In the present study, the authors sought to develop and characterize an orthotopic model of human ch...

Aims: To characterize the contractile properties of the bulbospongiosus (Bsm), isquiocavernosus (Ism), and pubococcygeus muscles (Pcm), and their involvement in the genesis of vaginal pressure in nulliparous and multiparous rabbits. Methods: Age-matched nulliparous and multiparous rabbits were used to record the isometric contractile responses o...

Background context: Metastases to the spine are a common source of severe pain in cancer patients. The secondary effects of spinal metastases include pain, bone fractures, hypercalcemia, and neurological deficits. As the disease progresses, pain severity can increase until it becomes refractory to medical treatments and leads to a decreased qualit...

This study explored the effect of electroacupuncture stimulation (EA) on alterations in the Hoffman reflex (H-reflex) response and gait locomotion provoked by spinal cord injury (SCI) in the rat. A compression lesion of the spinal cord was evoked by insufflating a Fogarty balloon located in the epidural space at the T8–9 spinal level of adult Wista...

In Traditional Chinese Medicine, acupuncture points (APs) have been emphasized as key elements that generate the therapeutic effects of acupuncture. At the spinal cord or su-praspinal level, sensory neurons located in the dorsal horn receive an extensive supply of sensory information from skin and muscle receptors through peripheral afferent nerves...

BACKGROUND Chordoma (CHO) is a slow-growing, malignant, locally aggressive cancer that is minimally responsive to conventional chemotherapy and radiotherapy. It presents high local recurrence after surgical resection. There are no animal models of spinal chordoma. METHODS 34 immunocompromised rats were engrafted in the lumbar spine with human CHO...

This study was aimed to explore the action of electroacupuncture (EA) stimulation on the alterations provoked by a spinal compression in the Hoffman Reflex (HR) evoked in plantar muscles by tibial nerve (TN) stimulation (at 0.2, 5 y 10HZ). Locomotor behavior and gait kinematic analysis of rats were also evaluated. The spinal lesion was made by insu...

Hypertension is a major risk factor for ischemic heart disease and stroke, leading causes of morbidity and death worldwide. Intrauterine growth restriction (IUGR), caused by an excess of glucocorticoid exposure to the fetus, produces an imbalance in oxidative stress altering many biochemical and epigenetic gene transcription processes exposing the...

Locomotion recovery after a spinal cord injury (SCI) includes axon regeneration, myelin preservation and increased plasticity in propriospinal and descending spinal circuitries. The combined effects of tamoxifen and exercise after a SCI were analyzed in this study to determine whether the combination of both treatments induces the best outcome in l...

Diversos estudios experimentales han mostrado que la EA activa a las fibras nerviosas de manera similar a lo que ocurre con la estimulación eléctrica aplicada directamente a los nervios periféricos. La diferencia estriba en que la EA es una estimulación percutánea, por medio de agujas, de un área muy pequeña de la piel, la cual es menos traumática...

Acupuncture is an ancient therapeutic modality that emerged from Traditional Chinese Medicine. The efficacy of acupuncture for the treatment of pain has been evaluated in numerous clinical trials, but its action has not been experimentally supported due to some conceptual and methodological limitations. Recently, neuronal electrical stimulation the...

The electrophysiological alterations in nerves due to diabetes are classically studied in relation to their instantaneous frequency, conduction velocity and amplitude. However, analysis of amplitude variability may reflect the occurrence of feedback loop mechanisms that adjust the output as a function of its previous activity could indicate fractal...

Acupuncture is an ancient therapeutic modality that emerged from Traditional Chinese Medicine. The efficacy of acupuncture for the treatment of pain has been evaluated in numerous clinical trials, but its action has not been experimentally supported due to some conceptual and methodological limitations. Recently, neuronal electrical stimulationther...

We performed experiments in cats with a spinal cord penetrating hemisection at T13-L1 level, with and without tamoxifen treatment. The results showed that the numbers of the ipsilateral and contralateral ventral horn neurons were reduced to less than half in the nontreated animals compared with the treated ones. Also, axons myelin sheet was preserv...

The hippocampus role in sensory-motor integration remains unclear. In these experiments we study its function in the locomotor control. To establish the connection between the hippocampus and the locomotor system, electrical stimulation in the CA1 region was applied and EMG recordings were obtained. We also evaluated the hindlimbs and forelimbs kin...

The progressive degeneration of the dopamine neurons of the pars compacta of substantia nigra and the consequent loss of the dopamine innervation of the striatum leads to the impairment of motor behavior in Parkinson's disease. Accordingly, an efficient therapy of the disease should protect and regenerate the dopamine neurons of the substantia nigr...

Object: Transection of peripheral nerves produces loss of sensory and/or motor function. After complete nerve cutting, the distal and proximal segment ends retract, but if both ends are bridged with unaltered chitosan, progesterone-impregnated chitosan, or silicone tubes, an axonal repair process begins. Progesterone promotes nerve repair and has...

Contents Oviductal regions show particular histological characteristics and functions. Tubal pathologies and hypothyroidism are related to primary and secondary infertility. The impact of hypothyroidism on the histological characteristics of oviductal regions has been scarcely studied. Our aim was to analyse the histological characteristics of ovid...

Several studies have shown that gonadotropin-releasing hormone (GnRH) have extra-pituitary roles, including neurotrophic effects. This study was to evaluate the effects of GnRH treatment on the spinal cord injury (SCI) of rats. Ovariectomized rats were divided into: sham SCI surgery (Sham), SCI treated with saline solution (SCI + SS), and SCI treat...

Sensory and social deprivation from the mother and littermates during early life disturbs the development of the central nervous system, but little is known about its effect on the development of the peripheral nervous system. To assess peripheral effects of early isolation, male rat pups were reared artificially in complete social isolation (AR);...

In this study, we compare the effects of pre- and post-natal food deprivation on the relative proportion of fibre types and contractile responses in the extensor digitorum longus (EDL) muscle of female and male rats at different post-natal ages. EDL muscles from undernourished male (UM) rats showed a higher proportion of Type IIB than IIA fibres an...

The aim of this study was to explore the effect of electroacupuncture (EA) applied in the Zusanli (ST36) and Sanyinjiao (SP6) points on the N1 component of the cord dorsum potential (CDP) evoked by electrical stimulation of the sural nerve (SU) in the rat. The experiments were performed in 44 Wistar rats (250-300 g) anesthetized with ketamine (100...

Spontaneous negative cord dorsum potentials (spontaneous CDPs) are produced by the activation of dorsal horn neurons distributed along the L4 to S1 spinal cord segments, in Rexed́s laminae III-VI, in the same region in which there are interneurons rhythmically bursting during fictive scratching in cats. An interesting observation is that spontaneou...

The longitudinal distribution of the cord dorsum potentials (CDPs) produced by electroacupuncture (EA) stimulation at acupuncture points (APs) located on the hind limbs of rats was analyzed in this study. Single electrical pulses (0.05 ms, 1 Hz) applied to the bladder (BL) and the gallbladder (GB) APs produced CDPs on several spinal segments and we...

Acupuncture is a therapeutic modality of the traditional chinese medicine, which has been widely accepted by the World Health Organization. Considerable effort has been made to disclose the spinal mechanisms involved in the antinociceptive effect of electroacupuncture (EA). However, practically there is not information on the actions of EA on cutan...

Pelvic and perineal striated muscles are relevant for reproduction and micturition in female mammals. Damage to these muscles is associated with pelvic organ prolapse and stress urinary incontinence. The fiber type composition of skeletal muscle influences the susceptibility for damage and/or regeneration. The aim of the present study was to determ...

In a previous study (Neurosci. Lett, 2004), we have shown an increment in trial-to-trial amplitude variability of the compound action potential (CAP) recorded in the sural (SU) nerve of the chronic undernourished rat. Subsequently we found a reduction in amplitude of the different components in the Cord Dorsum Potential (CDP) and of the Dorsal Root...

In the present study, we analyze the influence of chronic undernutrition on protein expression, muscle fiber type composition, and fatigue resistance of the fast extensor digitorum longus (EDL) muscle of male juvenile rats (45 ± 3 days of life; n = 25 and 31 rats for control and undernourished groups, respectively). Using 2D gel electrophoresis and...

The longitudinal distribution of the cord dorsum potentials (CDPs) produced by electro-acupuncture (EA) stimulation at acupuncture points (APs) located on the hind limbs of rats was analyzed in this study. Single electrical pulses (0.05 ms, 1 Hz) applied to the bladder (BL) and the gallbladder (GB) APs produced CDPs on several spinal segments and w...

The first electrophysiological evidence of the phenomenon of traveling electrical waves produced by populations of interneurons within the spinal cord was reported by our interdisciplinary research group. Two interesting observations derive from this study: first, the negative spontaneous cord dorsum potentials (CDPs) that are superimposed on the p...

Cancer is a major global public health problem responsible for one in every four deaths in the United States. Prostate cancer alone accounts for 29% of all cancers in men and is the sixth leading cause of death in men. It is estimated that up to 30% of patients with cancer will develop metastatic disease, the spine being one of the most frequently...

Objective: To determine changes in morphometry and expression of oestrogen receptors (OR) in the pubococcygeus and bulbospongiosus muscles, and the concentration of serum oestradiol associated with multiparity. Study design: Twelve chinchilla-breed female rabbits were divided into multiparas who had undergone four consecutive deliveries and age-...

In the anaesthetized cat, the acute section of the saphenous (Saph) and/or the superficial peroneal (SP) nerves was found to produce a long lasting increase of the field potentials generated in the dorsal horn by stimulation of the medial branch of the sural (mSU) nerve. This facilitation was associated with changes in the level of the tonic primar...

We analyze the effect of chronic undernourishment on extensor digitorum longus (EDL) muscle maturation in the rat. Cytochrome c oxidase (COX) and alkaline ATPase histoenzymatic techniques were used to determine the relative proportion of different fiber types (oxidative/glycolytic and type I, IIa/IId, or IIb, respectively) and their cross-sectional...

In this study, we proposed a simple but physiologically plausible network model that can reproduce both the sinusoidal electrical wave propagation and the spontaneous zero-lag synchronization experimentally observed in the cat spinal cord. Our model enhances the hypothesis of the coexistence of two alternative assemblies in the cat spinal cord.

The aim of this study was to determine the effect of chronic undernutrition on the content and release of γ-amino butyric acid (GABA) and glutamate (GLU) transmitters in the rat spinal cord. The release of [(3)H]-GABA and [(3)H]-GLU was determined by radioactive liquid scintillation techniques, and the concentrations of GABA and GLU in spinal cord...

The aim of this study was to determine the effect of chronic undernourishment on the amplitude depression of the first negative component in the cord dorsum potentials (N(1)-CDPs) caused by the conditioning stimulation of sensory cutaneous nerves in the rat spinal cord. Single electrical pulses (1Hz; 2 times threshold) applied to the sural (SU) ner...

Simultaneous recordings of cord dorsum potentials along the lumbo-sacral spinal cord of the anaesthetized cat revealed the occurrence of spontaneous synchronous negative (n) and negative-positive (np) cord dorsum potentials (CDPs). The npCDPs, unlike the nCDPs, appeared preferentially associated with spontaneous negative dorsal root potentials (DRP...

Hypothalamic-pituitary-adrenal gland axis (HPA) dysfunction is at the origen of the metabolic syndrome (MS) diseases appearance and development. Environmental, nutritional and genetic factors are to blame for the prenatal disease programming due to epigenetic modifications that the biochemical and hormonal apparatus fix to 'balance' a survival cond...