This study set out to investigate, for the first time, the distribution and colocalization pattern
of cocaine-and amphetamine-regulated transcript (CART) and one of the calcium binding-
-proteins: parvalbumin (PV) in the chinchilla’s hippocampus proper (HP). HP, consisting
of Ammon’s horn (CA) and the dentate gyrus (DG), is an important component of the limbic
system, involved in learning and memory processes. CA showed a higher immunoreactivity
of CART (-IR) compared to DG. CART-IR neurons were mainly observed in the molecular layer
of DG and in the pyramidal layer of CA. CART-IR fibers were present in the granular layer;
in the hilus numerous mossy fibers were detected, while in the molecular layer CART-IR fibers
were not found. In all CA fields (CA1-CA3), CART-IR fibers were only present in the lacunosum-molecular layer. Immunofluorescence with double- labeling showed that only CART-IR cells
stained positive for PV, whereas in CART-IR fibers there was no PV-positive reaction.
Our research supplements missing knowledge about the distribution and colocalization pattern
of CART with PV in the chinchilla’s hippocampus, and also provides a better understanding
of the similarities and differences among individuals of the same species and also with other
mammals.