Perivascular cholinesterase and morphological blood-brain barrier function

Area of Science:

• Neuroscience
• Vascular Biology
• Pharmacology

Background:

• The role of cholinesterase activity in cerebral microvessel walls is largely unknown.
• Systemic administration of physostigmine, a cholinesterase inhibitor, can open the blood-brain barrier.
• This observation suggested a role for perivascular cholinesterase in maintaining blood-brain barrier integrity.

Purpose of the Study:

• To investigate the function of cholinesterase activity in cerebral microvessel walls.
• To determine if perivascular cholinesterase is involved in maintaining blood-brain barrier function.
• To elucidate the mechanism behind physostigmine-induced blood-brain barrier opening.

Main Methods:

• Investigated the effects of physostigmine on blood-brain barrier permeability.
• Monitored physiological parameters including blood pressure and carbon dioxide levels.
• Analyzed the contribution of physostigmine-induced hypertension and hypercapnia to barrier opening.

Main Results:

• Physostigmine-induced blood-brain barrier opening is fully explained by acute hypertension and hypercapnia.
• The study found no evidence that perivascular cholinesterase directly maintains blood-brain barrier morphology.
• The enzyme's activity may act as a barrier to cholinergic agents.

Conclusions:

• Perivascular cholinesterase does not appear to play a direct role in maintaining blood-brain barrier integrity.
• The observed effects of physostigmine are secondary to systemic physiological changes.
• Further research is needed to understand the precise function of cholinesterase in cerebral microvessels, potentially as a barrier to cholinergic agents.