Apparatus for long-term ventricular access in the awake canine

Area of Science:

• Neuroscience
• Surgical Innovation

Background:

• Cerebrospinal fluid (CSF) research is crucial for understanding central nervous system (CNS) function.
• Previous methods for CSF sampling and infusion in awake animals were limited.
• The need for a reliable apparatus for repeated ventricular access in conscious canines was identified.

Purpose of the Study:

• To describe and evaluate a new apparatus for lateral ventricular cerebrospinal fluid (CSF) sampling and infusion in awake dogs.
• To assess the safety and efficacy of the apparatus for repeated experimental procedures.
• To investigate the central nervous system effects of peptide administration via the apparatus.

Main Methods:

• Development and application of a novel apparatus for ventricular cannulation in awake canines.
• Repeated CSF sampling and intracerebroventricular infusions of peptides (bombesin, somatostatin) over a 6- to 24-month period.
• Monitoring of CSF and peripheral blood peptide levels using radioimmunoassay.

Main Results:

• The apparatus allowed for safe and repeated CSF sampling and intracerebroventricular infusions in 25 dogs.
• Intracerebroventricular peptide administration resulted in detectable levels in CSF but not in peripheral blood, suggesting limited systemic leakage.
• Complications occurred in 10 dogs but were manageable, with three fatal outcomes (meningitis, seizures).

Conclusions:

• The described apparatus provides a viable method for repeated ventricular cannulation in awake canines.
• This tool facilitates the study of CSF dynamics and the central effects of administered substances.
• The findings support the use of this apparatus for CNS research without significant systemic peptide absorption.