ABSTRACT
Quantitative analysis of ChAT immunoreactive neurones was used to evaluate the protective potential of BDNF or NT-3 against retrograde changes in nucleus basalis magnocellularis (nbm) cholinergic neurones after unilateral partial devascularization of the rat neocortex. A daily intracerebroventricular dose of 12 micrograms, proven to be effective for NGF and aFGF in the same experimental paradigm, was administered by minipump infusion for a 1-week period. Thirty days after lesioning, neuronal shrinkage and loss of neuritic processes were not prevented by treatment. The results indicate that intracerebroventricularly delivered BDNF and NT-3 are not as effective as NGF and aFGF in protection of nbm cholinergic neurones against lesion-induced changes in adult rat brain.
Subject(s)
Basal Ganglia/cytology , Nerve Growth Factors/pharmacology , Nerve Tissue Proteins/pharmacology , Neurons/drug effects , Parasympathetic Nervous System/cytology , Animals , Autonomic Pathways/cytology , Autonomic Pathways/drug effects , Basal Ganglia/drug effects , Brain-Derived Neurotrophic Factor , Cerebral Cortex/blood supply , Cerebrovascular Circulation/physiology , Choline O-Acetyltransferase/immunology , Choline O-Acetyltransferase/metabolism , Immunohistochemistry , Injections, Intraventricular , Male , Nerve Growth Factors/administration & dosage , Nerve Tissue Proteins/administration & dosage , Neurites/drug effects , Neurotrophin 3 , Parasympathetic Nervous System/drug effects , Rats , Rats, WistarABSTRACT
The neurotrophin gene family comprises four structurally related basic proteins, NGF, BDNF, NT-3 and NT-4/5. Despite high structural homology, these neurotrophins operate via different high-affinity membrane receptors, differ in target specificity, patterns of spatial and temporal distribution and responses to injury of the neuronal tissue. Based on the recent data, some aspects of BDNF and NT-3 neurotrophin activity and their possible role in normal and damaged nervous system are presented. Different effectiveness of exogenously applied neurotrophins in the injured brain as a consequence of responsiveness of particular neuronal populations to these factors, dose requirements, route of delivery, parenchymal penetration and target availability is discussed.
