Evolución ontogenética de un sistema de neurotransmisión en encéfalo y médula de rata

Abstract

Our goal is to search how inhibition is organised in rat Central Nervous System. In order to do it, we review the preface, the role of the neurotransmitter Gamma-Amino-Butyric acid, as well as the biosynthesis enzyme, the receptors, and how this neurotransmitter acts when it is at the synaptic cleft, on the post synaptic cell, producing an inhibitory post synaptic potential. Also we include a review of the distribution of GABA, on the different cerebral areas on adult animals. We can conclude that GABA is the most important inhibitory neurotransmitter in CNS in adults. A bibliographic review has been done in order to localise the neurotransmitter during development, on prenatal and postnatal periods, in different brain areas as development progress. Our objective has been create a comprehensive diagrams to localise GABA, during these periods till to achieve the adult distribution. The maps cover the period from ED-11 till PND-21/28. ED-11 is the first date that the sintesis enzyme is detected and PND-21/28 is the date proposed as the maturation of the gabaergic system. In these maps we can see how the neurotransmitter is detected in all new areas during the development of CNS. Along the morphological changes the gabaergic system also goes through functional changes, because during this developmental period the GABA acts as excitatory neurotransmitters: depolarising the post-synaptic cell, allowing the organisation of circuit in nearby areas. When all the process is finished, the neurotransmitter GABA became an inhibitory one, due to the change of chloride concentration as well as the structure of the receptor GABA-A. Finally we found a complete organised inhibitory system where the GABA acts producing hiperpolarization on the adult nervous system