*3.3. Morphological Studies of the Whole Brain of Young and Old Animals*

In the present study, the attention was focused on the expression and distribution of either mRNA (ISH) and protein (IHC) onto the areas responsible for the regulation of food intake: the ventral part of the telencephalon and the diencephalon in toto. However, positive labeling was also detected outside the above-mentioned areas, such as olfactory bulbs and dorsal telencephalon in the forebrain, optic tectum, and semicircular tori in the midbrain, which are known to mediate food appetite behavior [32]. Table 1 summarizes positive neurons and fibers localization of NUCB2B mRNA/Nesf-1 protein in young and old brains of *N. furzeri*. The neuroanatomical terminology followed the *N. furzeri* brain atlas [46].


**Table 1.** Summary of positive perikarya and fibers localization of NUCB2B mRNA and Nesf-1 protein in the forebrain of young and old *N. furzeri*.
