Dissecting the Non-human Primate Brain in Stereotaxic Space

Summary

The non-human primate is an important translational species for our understanding of the normal processing of the brain. The anatomical organization of the primate brain can provide important insights into normal and pathological conditions in humans.

Abstract

The use of non-human primates provides an excellent translational model for our understanding of developmental and aging processes in humans^1-6. In addition, the use of non-human primates has recently afforded the opportunity to naturally model complex psychiatric disorders such as alcohol abuse⁷. Here we describe a technique for blocking the brain in the coronal plane of the vervet monkey (Chlorocebus aethiops sabeus) in the intact skull in stereotaxic space. The method described here provides a standard plane of section between blocks and subjects and minimizes partial sections between blocks. Sectioning a block of tissue in the coronal plane also facilitates the delineation of an area of interest. This method provides manageable sized blocks since a single hemisphere of the vervet monkey yields more than 1200 sections when slicing at 50μm. Furthermore by blocking the brain into 1cm blocks, it facilitates penetration of sucrose for cyroprotection and allows the block to be sliced on a standard cryostat.

Protocol

Part 1: Pre-processing of tissue

1. Tissue should be well perfused with paraformaldehyde, glutaraldehyde, or formalin. This can be achieved through standard transcardial perfusion typically used to harvest other organs. In the present study the subject was deeply sedated with ketamine hydrochloride (10 mg/kg, i.m.), euthanized with an overdose of sodium pentobarbital (25 mg/kg, i.v.) and perfused transcardially with 0.1 M PBS until completely exsanguinated.This is followed by a 4% paraformaldehyde solution in PBS for 5 min (~1 liter).

Part 2: Stereotaxic blocking

1. Prior to placing the head into the stereotaxic frame....

Discussion

The St. Kitts vervet (Chlorocebus aethiops sabeus) is an Old World primate with similar patterns and rates of cortical and subcortical brain development to that of humans. This species has been used to model complex human behavioral disorders like anxious behavior, hypertension⁸, hemispherectomy⁹, Parkinson’s disease¹⁰, Alzhemier’s disease¹¹, and alcohol abuse¹². More recently, this species has been used to study the neuroanatomical effects of na.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Scalpel	Fine Science Tools	10003-12
Scalpel blades	Fine Science Tools	10011-00
Scissors	Fine Science Tools	14090-11	Any surgical scissors are sufficient
Rongeurs	Fine Science Tools	16121-14
Forceps	Fine Science Tools	11027-12
Filter paper	Fisher Scientific	09-924-150
Stereotaxic Frame	Kopf Instruments
Tissue slicing blade	Thomas Scientific