Antonio García | Fresenius Kabi (original) (raw)

Papers by Antonio García

Research paper thumbnail of Chondroitin Sulfate Induces Depression of Synaptic Transmission and Modulation of Neuronal Plasticity in Rat Hippocampal Slices

Neural Plasticity, 2015

It is currently known that in CNS the extracellular matrix is involved in synaptic stabilization ... more It is currently known that in CNS the extracellular matrix is involved in synaptic stabilization and limitation of synaptic plasticity. However, it has been reported that the treatment with chondroitinase following injury allows the formation of new synapses and increased plasticity and functional recovery. So, we hypothesize that some components of extracellular matrix may modulate synaptic transmission. To test this hypothesis we evaluated the effects of chondroitin sulphate (CS) on excitatory synaptic transmission, cellular excitability, and neuronal plasticity using extracellular recordings in the CA1 area of rat hippocampal slices. CS caused a reversible depression of evoked field excitatory postsynaptic potentials in a concentration-dependent manner. CS also reduced the population spike amplitude evoked after orthodromic stimulation but not when the population spikes were antidromically evoked; in this last case a potentiation was observed. CS also enhanced paired-pulse facilitation and long-term potentiation. Our study provides evidence that CS, a major component of the brain perineuronal net and extracellular matrix, has a function beyond the structural one, namely, the modulation of synaptic transmission and neuronal plasticity in the hippocampus.

Research paper thumbnail of Desensitized nicotinic receptors that, however, afford cytoprotection in bovine chromaffin cells

Journal of Molecular Neuroscience, 2006

Research paper thumbnail of Inhibition of N and PQ calcium channels by calcium entry through L channels in chromaffin cells

Research paper thumbnail of Acetylcholine and potassium elicit different patterns of exocytosis in chromaffin cells when the intracellular calcium handling is disturbed

Research paper thumbnail of Riesz bases in related to sampling in shift-invariant spaces

Research paper thumbnail of Approximation from shift-invariant spaces by generalized sampling formulas

Research paper thumbnail of Body Awareness: Construct and Self-Report Measures

Research paper thumbnail of Differential effects of the neuroprotectant lubeluzole on bovine and mouse chromaffin cell calcium channel subtypes

British Journal of Pharmacology, 1997

Research paper thumbnail of Worth the ‘EEfRT’? The Effort Expenditure for Rewards Task as an Objective Measure of Motivation and Anhedonia

Research paper thumbnail of Reduced Spontaneous Eye Blink Rates in Recreational Cocaine Users: Evidence for Dopaminergic Hypoactivity

Research paper thumbnail of Losing the Big Picture: How Religion May Control Visual Attention

Research paper thumbnail of Reduced Attentional Scope in Cocaine Polydrug Users

Plos One, 2009

Cocaine is Europe's second preferred recreational... more Cocaine is Europe's second preferred recreational drug after cannabis but very little is known about possible cognitive impairments in the upcoming type of recreational cocaine user (monthly consumption). We asked whether recreational use of cocaine impacts early attentional selection processes. Cocaine-free polydrug controls (n = 18) and cocaine polydrug users (n = 18) were matched on sex, age, alcohol consumption, and IQ (using the Raven's progressive matrices), and were tested by using the Global-Local task to measure the scope of attention. Cocaine polydrug users attended significantly more to local aspects of attended events, which fits with the idea that a reduced scope of attention may be associated with the perpetuation of the use of the drug.

Research paper thumbnail of Paradoxical facilitation of exocytosis by inhibition of L-type calcium channels of bovine chromaffin cells

Biochemical and Biophysical Research Communications, 2011

Ca2+ entry through the L-subtype (α1D, Cav1,3) of voltage-dependent calcium channels (VDCCs) seem... more Ca2+ entry through the L-subtype (α1D, Cav1,3) of voltage-dependent calcium channels (VDCCs) seems to selectively regulate the endocytotic response after the application of a single depolarizing pulse to voltage-clamped bovine chromaffin cells. Here we have found that L channel blockade with nifedipine transformed the exocytotic responses elicited by a double-pulse protocol, from depression to facilitation. This apparent paradoxical effect was

Research paper thumbnail of Permissive role of sphingosine on calcium-dependent endocytosis in chromaffin cells

Pflugers Archiv-european Journal of Physiology, 2010

Sphingosine has been shown to modulate neurotransmitter release. Because membrane fusion and fiss... more Sphingosine has been shown to modulate neurotransmitter release. Because membrane fusion and fission involve lipid metabolism, we asked here whether sphingosine had a role in regulating endocytosis. To explore this hypothesis, we monitored changes of membrane capacitance (Cm) to study the effects of intracellular sphingosine on membrane retrieval after chromaffin cell stimulation with depolarising pulses (DPs). We found that: (1)

Research paper thumbnail of Opioid Inhibition of Ca 2+ Channel Subtypes in Bovine Chromaffin Cells: Selectivity of Action and Voltage-dependence

European Journal of Neuroscience, 1996

Research paper thumbnail of Hypoxia-elicited catecholamine release is controlled by L-type as well as N/PQ types of calcium channels in rat embryo chromaffin cells

American journal of physiology. Cell physiology, 2014

At early life, the adrenal chromaffin cells respond with a catecholamine surge under hypoxic cond... more At early life, the adrenal chromaffin cells respond with a catecholamine surge under hypoxic conditions. This response depends on Ca(2+) entry through voltage-activated calcium channels (VACCs). We have investigated here three unresolved questions that concern this response in rat embryo chromaffin cells (ECCs): 1) the relative contribution of L (α1D, Cav1.3), N (α1B, Cav2.2), and PQ (α1A, Cav2.1) to the whole cell Ca(2+) current (ICa); 2) the relative contribution of L and N/PQ channels to the cytosolic Ca(2+) elevations triggered by hypoxia (Δ[Ca(2+)]c); and 3) the role of L and non-L high-VACCs in the regulation of the catecholamine surge occurring during prolonged (1 min) hypoxia exposure of ECCs. Nimodipine halved peak ICa and blocked 60% the total Ca(2+) entry during a 50-ms depolarizing pulse to 0 mV (QCa). Combined ω-agatoxin IVA plus ω-conotoxin GVIA (Aga/GVIA) blocked 30% of both ICa peak and QCa. This relative proportion of L- and non-L VACCs was corroborated by Western b...

Research paper thumbnail of Right-Angled" Stapled Latero-lateral Duodenojejunal Anastomosis in the Duodenal Switch

Obesity Surgery, 2005

A simplified technique to perform the duodeno-enteral anastomosis in the duodenal switch is prese... more A simplified technique to perform the duodeno-enteral anastomosis in the duodenal switch is presented. A linear stapled duodeno-jejunal side-to-side anastomosis is performed. The technique is easy and rapid to perform, avoids passing an anvil through the mouth of the patient and is safe for the patient, with satisfactory short-term results.

Research paper thumbnail of E-cadherin, laminin and collagen IV expression in the evolution from dysplasia to oral squamous cell carcinoma

Medicina oral, patología oral y cirugía bucal, 2006

Study the loss or reduction of the cellular adhesion mediated for E-cadherin in oral leukoplakias... more Study the loss or reduction of the cellular adhesion mediated for E-cadherin in oral leukoplakias, oral squamous cell carcinomas and metastatic nodules. Study the loss of continuity of the laminin and collagen IV expression in the epithelial basal membrane from the biological development of the oral leukoplakias and oral carcinomas. we have studied 124 samples of patient pays leukoplakias and oral carcinomas with diverse diagnosis that embrace from normal epithelium (13 samples), mild dysplasias (2), moderate dysplasias (12), in situ carcinomas (13), microinvasive carcinomas (11) oral squamous cell carcinomas (64 samples) and metastatic nodules (9). 7 blocks of tissue microarrays were built with needle of 2mm and was carried out a study by means of immunohistochemical technique for E-cadherin (clone 36, Biogenex), Laminin (078P, Biogenex) and Collagen IV (PHM12, Biogenex). In Mild and Moderate Dysplasias the results present loss of E-cadherin, Laminin, and Collagen IV (20%) expressi...

Research paper thumbnail of A comparison between acetylcholine-like action potentials and square depolarizing pulses in triggering calcium entry and exocytosis in bovine chromaffin cells

Journal of Molecular Neuroscience, 2006

Research paper thumbnail of A two-step model for acetylcholine control of exocytosis via nicotinic receptors

Biochemical and Biophysical Research Communications, 2008

The view that Ca2+ entry through voltage-dependent Ca2+ channels (VDCC) and through nicotinic rec... more The view that Ca2+ entry through voltage-dependent Ca2+ channels (VDCC) and through nicotinic receptors for acetylcholine (nAChRs) causes equal catecholamine release responses in chromaffin cells, was reinvestigated here using new protocols. We have made two-step experiments consisting in an ACh prepulse followed by a depolarizing pulse (DP). In voltage-clamped bovine chromaffin cells an ACh prepulse caused a slow-rate release but

Research paper thumbnail of Chondroitin Sulfate Induces Depression of Synaptic Transmission and Modulation of Neuronal Plasticity in Rat Hippocampal Slices

Neural Plasticity, 2015

It is currently known that in CNS the extracellular matrix is involved in synaptic stabilization ... more It is currently known that in CNS the extracellular matrix is involved in synaptic stabilization and limitation of synaptic plasticity. However, it has been reported that the treatment with chondroitinase following injury allows the formation of new synapses and increased plasticity and functional recovery. So, we hypothesize that some components of extracellular matrix may modulate synaptic transmission. To test this hypothesis we evaluated the effects of chondroitin sulphate (CS) on excitatory synaptic transmission, cellular excitability, and neuronal plasticity using extracellular recordings in the CA1 area of rat hippocampal slices. CS caused a reversible depression of evoked field excitatory postsynaptic potentials in a concentration-dependent manner. CS also reduced the population spike amplitude evoked after orthodromic stimulation but not when the population spikes were antidromically evoked; in this last case a potentiation was observed. CS also enhanced paired-pulse facilitation and long-term potentiation. Our study provides evidence that CS, a major component of the brain perineuronal net and extracellular matrix, has a function beyond the structural one, namely, the modulation of synaptic transmission and neuronal plasticity in the hippocampus.

Research paper thumbnail of Desensitized nicotinic receptors that, however, afford cytoprotection in bovine chromaffin cells

Journal of Molecular Neuroscience, 2006

Research paper thumbnail of Inhibition of N and PQ calcium channels by calcium entry through L channels in chromaffin cells

Research paper thumbnail of Acetylcholine and potassium elicit different patterns of exocytosis in chromaffin cells when the intracellular calcium handling is disturbed

Research paper thumbnail of Riesz bases in related to sampling in shift-invariant spaces

Research paper thumbnail of Approximation from shift-invariant spaces by generalized sampling formulas

Research paper thumbnail of Body Awareness: Construct and Self-Report Measures

Research paper thumbnail of Differential effects of the neuroprotectant lubeluzole on bovine and mouse chromaffin cell calcium channel subtypes

British Journal of Pharmacology, 1997

Research paper thumbnail of Worth the ‘EEfRT’? The Effort Expenditure for Rewards Task as an Objective Measure of Motivation and Anhedonia

Research paper thumbnail of Reduced Spontaneous Eye Blink Rates in Recreational Cocaine Users: Evidence for Dopaminergic Hypoactivity

Research paper thumbnail of Losing the Big Picture: How Religion May Control Visual Attention

Research paper thumbnail of Reduced Attentional Scope in Cocaine Polydrug Users

Plos One, 2009

Cocaine is Europe's second preferred recreational... more Cocaine is Europe's second preferred recreational drug after cannabis but very little is known about possible cognitive impairments in the upcoming type of recreational cocaine user (monthly consumption). We asked whether recreational use of cocaine impacts early attentional selection processes. Cocaine-free polydrug controls (n = 18) and cocaine polydrug users (n = 18) were matched on sex, age, alcohol consumption, and IQ (using the Raven's progressive matrices), and were tested by using the Global-Local task to measure the scope of attention. Cocaine polydrug users attended significantly more to local aspects of attended events, which fits with the idea that a reduced scope of attention may be associated with the perpetuation of the use of the drug.

Research paper thumbnail of Paradoxical facilitation of exocytosis by inhibition of L-type calcium channels of bovine chromaffin cells

Biochemical and Biophysical Research Communications, 2011

Ca2+ entry through the L-subtype (α1D, Cav1,3) of voltage-dependent calcium channels (VDCCs) seem... more Ca2+ entry through the L-subtype (α1D, Cav1,3) of voltage-dependent calcium channels (VDCCs) seems to selectively regulate the endocytotic response after the application of a single depolarizing pulse to voltage-clamped bovine chromaffin cells. Here we have found that L channel blockade with nifedipine transformed the exocytotic responses elicited by a double-pulse protocol, from depression to facilitation. This apparent paradoxical effect was

Research paper thumbnail of Permissive role of sphingosine on calcium-dependent endocytosis in chromaffin cells

Pflugers Archiv-european Journal of Physiology, 2010

Sphingosine has been shown to modulate neurotransmitter release. Because membrane fusion and fiss... more Sphingosine has been shown to modulate neurotransmitter release. Because membrane fusion and fission involve lipid metabolism, we asked here whether sphingosine had a role in regulating endocytosis. To explore this hypothesis, we monitored changes of membrane capacitance (Cm) to study the effects of intracellular sphingosine on membrane retrieval after chromaffin cell stimulation with depolarising pulses (DPs). We found that: (1)

Research paper thumbnail of Opioid Inhibition of Ca 2+ Channel Subtypes in Bovine Chromaffin Cells: Selectivity of Action and Voltage-dependence

European Journal of Neuroscience, 1996

Research paper thumbnail of Hypoxia-elicited catecholamine release is controlled by L-type as well as N/PQ types of calcium channels in rat embryo chromaffin cells

American journal of physiology. Cell physiology, 2014

At early life, the adrenal chromaffin cells respond with a catecholamine surge under hypoxic cond... more At early life, the adrenal chromaffin cells respond with a catecholamine surge under hypoxic conditions. This response depends on Ca(2+) entry through voltage-activated calcium channels (VACCs). We have investigated here three unresolved questions that concern this response in rat embryo chromaffin cells (ECCs): 1) the relative contribution of L (α1D, Cav1.3), N (α1B, Cav2.2), and PQ (α1A, Cav2.1) to the whole cell Ca(2+) current (ICa); 2) the relative contribution of L and N/PQ channels to the cytosolic Ca(2+) elevations triggered by hypoxia (Δ[Ca(2+)]c); and 3) the role of L and non-L high-VACCs in the regulation of the catecholamine surge occurring during prolonged (1 min) hypoxia exposure of ECCs. Nimodipine halved peak ICa and blocked 60% the total Ca(2+) entry during a 50-ms depolarizing pulse to 0 mV (QCa). Combined ω-agatoxin IVA plus ω-conotoxin GVIA (Aga/GVIA) blocked 30% of both ICa peak and QCa. This relative proportion of L- and non-L VACCs was corroborated by Western b...

Research paper thumbnail of Right-Angled" Stapled Latero-lateral Duodenojejunal Anastomosis in the Duodenal Switch

Obesity Surgery, 2005

A simplified technique to perform the duodeno-enteral anastomosis in the duodenal switch is prese... more A simplified technique to perform the duodeno-enteral anastomosis in the duodenal switch is presented. A linear stapled duodeno-jejunal side-to-side anastomosis is performed. The technique is easy and rapid to perform, avoids passing an anvil through the mouth of the patient and is safe for the patient, with satisfactory short-term results.

Research paper thumbnail of E-cadherin, laminin and collagen IV expression in the evolution from dysplasia to oral squamous cell carcinoma

Medicina oral, patología oral y cirugía bucal, 2006

Study the loss or reduction of the cellular adhesion mediated for E-cadherin in oral leukoplakias... more Study the loss or reduction of the cellular adhesion mediated for E-cadherin in oral leukoplakias, oral squamous cell carcinomas and metastatic nodules. Study the loss of continuity of the laminin and collagen IV expression in the epithelial basal membrane from the biological development of the oral leukoplakias and oral carcinomas. we have studied 124 samples of patient pays leukoplakias and oral carcinomas with diverse diagnosis that embrace from normal epithelium (13 samples), mild dysplasias (2), moderate dysplasias (12), in situ carcinomas (13), microinvasive carcinomas (11) oral squamous cell carcinomas (64 samples) and metastatic nodules (9). 7 blocks of tissue microarrays were built with needle of 2mm and was carried out a study by means of immunohistochemical technique for E-cadherin (clone 36, Biogenex), Laminin (078P, Biogenex) and Collagen IV (PHM12, Biogenex). In Mild and Moderate Dysplasias the results present loss of E-cadherin, Laminin, and Collagen IV (20%) expressi...

Research paper thumbnail of A comparison between acetylcholine-like action potentials and square depolarizing pulses in triggering calcium entry and exocytosis in bovine chromaffin cells

Journal of Molecular Neuroscience, 2006

Research paper thumbnail of A two-step model for acetylcholine control of exocytosis via nicotinic receptors

Biochemical and Biophysical Research Communications, 2008

The view that Ca2+ entry through voltage-dependent Ca2+ channels (VDCC) and through nicotinic rec... more The view that Ca2+ entry through voltage-dependent Ca2+ channels (VDCC) and through nicotinic receptors for acetylcholine (nAChRs) causes equal catecholamine release responses in chromaffin cells, was reinvestigated here using new protocols. We have made two-step experiments consisting in an ACh prepulse followed by a depolarizing pulse (DP). In voltage-clamped bovine chromaffin cells an ACh prepulse caused a slow-rate release but