Rafael A. Vargas V.
GROUP LEADER NAME (as it appears in publications):
Rafael Antonio Vargas Vargas, MD, MSc, PhD
AFFILIATION:
Department of Physiological Sciences. School of Medicine. Pontificia Universidad Javeriana. Bogotá, Colombia.
TEL:* (57-1) 3208320 Ext. 2782
FAX:* (57-1) 3208320 Ext. 2782
EMAIL:*rafael.vargas@javeriana.edu.co; rvargas3200@hotmail.com
GROUP NAME / RESEARCH INTEREST IN FEW WORDS:
ZEBRAFISH GROUP. We have tree lines of research:
The neural control of cardiovascular function.
Spermatozoides and antioxidants.
Obesity and diabetes.
SHORT SUMMARY OF RESEARCH INTEREST (MAX. 200 WORDS):
In the field of neural control of cardiovascular function, we are exploring GABA neurotransmitter and its influence in cardiovascular regulation. Stress and cardiovascular disease have strong relationship and GABA as an inhibitory neurotransmitter could modulate neural control of cardiovascular function. This topic is a relevant area, with applications in basic (physiopathology, pharmacology) and clinical fields (cardiology, neurology).
In the field of zebrafish spermatozoids and antioxidants, we explore the effect of antioxidants over germ cells. This important area has applications in pharmacology, in vitro fertilization and long term preservation of cells.
The third line, obesity and diabetes, explore the obesity and its relationship with diabetes mellitus type II (obesity-induced type 2 diabetes). This area is relevant to basic and clinical research and it has applications in pathology, pharmacology, endocrinology, cardiology and neurology.
In each research area we are interested to use zebrafish from larvae to adult ages, which will give us information throughout zebrafish lifespan.
LIST OF UP TO FIVE RELEVANT PUBLICATIONS:
1- Spontaneous neural activity of the anterodorsal lobe and entopeduncular nucleus in adult zebrafish: A putative homologue of hippocampal sharp waves. Behavioural Brain Research 229(1): 10 – 20 2- Zebrafish brain a simple in vivo and in vitro model for studying spontaneous neural activity during development. Advances in physiology education 35(2):188-196.
GROUP MEMBERS (NAME, POSITION, EMAIL):*
1- Isabel Cristina Vazquez. MV, MSc. Assistant Professor.
2- Jesús Armando Sánchez. MD, MSc. Associated Professor.
3- Alain Riveros. MD, MSc. Assistant Professor.
4- Ignacio Zarante. MD – PhD. Associated professor.
5- Esperanza Holguín. MD – MSc. Assistant Professor.
6- André Riveros. Biol. PhD. Assistant Professor.
FISH FACILITIES (TYPE OF FISH SYSTEM/TANKS, CAPACITY, ETC.)*
We have a basic, custom-made, low cost fish facility system. We have five tanks each one of 25 liters
FISH LINES KEPT IN STOCK:*
We have around 100 males and females wild type.
OTHER EQUIPMENT RELATED TO ZEBRAFISH RESEARCH*
Inverted microscope.
Stereo microscope.
Research data acquisition system – PowerLab 4/35 (consist of hardware and software).
Laminar flow hood.
Carbon dioxide incubator.
Isolated perfused organs system.
LAB EXPERTISE AND TECHNICAL CAPABILITIES (RELATED TO ZEBRAFISH RESEARCH)*
SKILLS
Electrophysiology (TEVC and extra-cellular techniques) for examination of neural
transmission, synaptic function and synaptic plasticity.
Small animal surgery.
In vitro models: nerves, squeletal muscle, oocytes, Zebrafish brain.
Microinjection for heterologous expression.
OTHER RELEVANT INFORMATION:*
Cardiovascular activity is regulated by controlling several factors including neural, endocrine and immune systems. Some pathologies are associated with abnormal cardiovascular control. The primary goal our laboratory is to study the mechanisms that underlie the neural pathways that control cardiovascular activity, not only at central level but also at peripheral level. Zebrafish is a model unique, simple and economical that permits to study this topic from different levels including the cellular, tissue, isolated organ until a systemic level.
We are interesting in GABA (gamma aminobutyric acid) signal and its relationship with cardiovascular control. GABA is a widespread inhibitor neurotransmitter in central nervous system and has relationship with diverse neurological disease as epilepsy, anxiety and stress. Also GABA is a target for many drugs including anesthetics, hypnotic, ansiolitic agents. Patients with neurological disease have alterations in cardiac activity and it has been hypothesized that sudden dead could be caused as a consequence of problems in neural control of the heart. GABA is present in central nervous system and it has been identified not only in the neocortex but also in cardiovascular centers located in brainstem. Additionally, GABA has been identified in some structures in peripheral nervous system; however it is not known which the role at this level is. We are interested to explore GABA function related with cardiovascular function from central to peripheral nervous system.
For our studies we work with pharmacological agents and record activity of zebrafish heart in video. We study this in zebrafish larvae because larvae are completely transparent making them appropiated for studying heart activity. We use gabaergic and antigabaergic substances to explore changes in the cardiovascular activity under the effect of these substances. In video recordings we focus on studying heart rate variability (HRV) because this is a parameter which can show us the influence of nervous system over cardiovascular system.
Figura A. Acuarios con calefacción y filtros. Figura B. Ejemplar de pez cebra adulto. Figura C. Larvas de pez cebra de 5 días postfertilización (dpf) en caja de petri. Figura D. Larva de pez cebra de 5 dpf. Objetivo 0,5X. Figura E. Embrión de 24 horas postfertilización (hpf). Objetivo 10X. Figura F. Silueta cardiaca en larva de 5 dpf. Objetivo 40X. Flechas señalan silueta cardiaca. Imágenes obtenidas en Laboratorio de Fisiología del Departamento de Ciencias Fisiológicas. Facultad de Medicina. PUJ