Introduction: The immunohistochemical method was used to follow the expression ofneuropeptide Y in the course of pre ischemia of the rat brain. The aim of the study was to define all the areas of expression of this protein, show their localization, their map of distribution and histological types.
Material and methods: All the sections of telencephalon, diencephalon and midbrain were studied in resistant, and transitory ischemia, which enabled us to observe the reaction of neurons to an ischemic attack or to repeated attacks. The mapping was done for all three proteins by introducing our results into the maps of rat brain atlas, George Paxinos, Charles Watson. Photographing and protein expression was done using Analysis program.
Results: The results of this research show that there is a differens in reaction between the resistant and transitory ischemia groups of rats, especially in the caudoputamen, gyrus dentatus, corpus amygdaloideum, particularly in the medial nucleus. The mapping shows the reaction in caudoputamen, gyrusdentatus, corpus amygdaloideum- especially in the central nucleus, then in the sensitive and secondary auditory cortex, mostly in the laminae V/VI, but less in neuron groups CA1, CA2, CA3 of hippocampus.
Discussion: The phylogenetically older parts of the brain-rhinencephalon, also showed reaction, which lead us to conclude that both newer and older brain structures reacted immunohistochemically. Histological data have shown that small neurons are most commonly found while the second most common ones are big pyramidal cells of multipolar and bipolar type, with a different body shape.
Conclusion: Our findings have confirmed the results obtained in some rare studies dealing with this issue, and offered a precise and detailed map of cells expressing neuropeptide Y in the rat brain following ischemic attack.