Brain Microdialysis

DE MACEDO, C.E.A.; CUADRA G.; GOBAILLE, S.; DE MORAES MELLO, L.E.A.; LEVY ANDERSEN, M.; TUFIK, S.

Rodent Model as Tools in Ethical Biomedical Research

Springer International Publishing

Año: 2016; p. 217 - 233

Behavioral, cognitive, and emotional phenomena are ultimately encoded by intricate neural networks. During neurotransmission, which involves the movement of several chemicals and ions across the neural membrane, chemical messengers released during brief time intervals into the synaptic gap interact with receptors on the postsynaptic neuron. This can lead to cellular changes, such as an altered membrane potential, gene expression, the release of growth factors, metabolism, and altered responsiveness to further stimuli. It is also well known that numerous neurotransmitters coexist in a given synaptic bouton and that they could be released at different times. In addition, axon terminals of amino acidergic, cholinergic, neuroaminergic, and peptidergic neurons converge in the same brain region. These terminals can become active at different times yet participate in the same function. In vivo experiments have yielded many insights into the regulation of neurotransmission in neuronal circuits and the extracellular microenvironment. However, in vivo measurements are complicated by several factors, such as the wide variety of brain chemicals (~200 neuroactive compounds identified), the rapid fluctuations in neurotransmitter levels by the reuptake process and enzymatic degradation, the structural heterogeneity of the brain, and the occurrence of other cell types that also may release neurotransmitters. This neurochemical complexity demands sensitivity and versatility of the analytical methods used for chemical determination.