Complete 3D visualization of primate striosomes by KChIP1 immunostaining

Area of Science:

• Neuroscience
• Neuroanatomy
• Cellular Biology

Background:

• Striosomes are integral components of the striatum, involved in motor control, reward, and cognition.
• Previous understanding of striosome organization lacked detailed quantitative analysis, particularly in primates.
• Identifying novel markers is crucial for detailed structural investigation of neuronal populations.

Purpose of the Study:

• To perform high-resolution 3D reconstruction and morphometric analysis of striosomes in macaque monkeys.
• To identify and characterize invariant quantitative features of striosome organization.
• To explore the relationship between striosome structure and potential function within the striatum.

Main Methods:

• Utilized immunocytochemistry with potassium channel interacting protein 1 (KChIP1) as a novel marker for striosomes.
• Employed high-resolution 3D reconstruction techniques.
• Performed quantitative morphometric analysis, including skeletonization, to measure branch dimensions and orientations.

Main Results:

• Striosomes form a connected reticulum with distinct planar sheets and finger-like branches in the macaque striatum.
• Individual striosome branches exhibit consistent diameters (355 ± 108.5 µm) and lengths (1,013 ± 751 µm), following a log-normal distribution.
• Striosome branches display three preferred, approximately orthogonal orientation preferences, suggesting a lattice-like structure.

Conclusions:

• Despite apparent spatial variability, striosomes possess invariant quantitative features, including branch dimensions and orientations.
• These invariant features suggest a fundamental, possibly lattice-like, organizational principle within the striatum.
• The findings provide insights into striatal function, development, and potential pathophysiology, highlighting KChIP1 as a valuable marker.