Distribuição do óxido nítrico no compartimento subcortical do telencéfalo e hipocampo do Mocó (Kerodon rupestris)

Abstract

Nitric oxide (NO) is a gaseous molecule that acts as a neurotransmitter, regulating synaptic events and participating in neural functions such as memory and learning. In the nervous system, NO is catalysed by neuronal nitric oxide synthase (nNOS). As a gaseous molecule, NO can diffuse freely trespassing the cells membrane. Because of this NO can act as a retrograde neurotransmitter and is usually treated as a local moderator. NO and nNOS are highly conserved among species and are present in the nervous system of many vertebrates. We performed immunohistochemical anti-nNOS and histochemical for NADPH-diaphorase in order to investigate the distribution of nitrergic cells in the subcortical compartment of the rock cavy (Kerodon rupestris) telencephalon. The data show a heterogeneous distribution of neurons immunoreactive to nNOS or with NADPH-diaphorase activity throughout the subcortical compartment. Neurons immunoreactive to nNOS were observed in the nucleus accumbens, associating NO with mechanisms of addiction and reward; in the nuclei of the amygdala and in the hippocampus, that are associated with learning and memory; in the bed nucleus of the stria terminalis, associated to defense behaviors, analgesia and cardiovascular functions; and in the basal nuclei, suggesting a putative neuroprotector role and neural regulation of the movement, being still associated with neurodegenerative diseases in these regions. The distribution of NO in the subcortical telencephalon of the rock cavy is broad, heterogeneous and complex, suggesting a broad role of NO in the cerebral functions of this species. In addition, the mapping of nNOS distribution is being important for the morphological definition of the rock cavy's brain areas in comparison with other species of rodents and other mammals.