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Adeno-associated virus (AAV) vector has been developed as an attractive gene delivery system with proven safety. Glial cell line-derived neurotrophic factor (GDNF) is proposed to be a promising therapeutic agent for amyotrophic lateral sclerosis (ALS) and other motor neuron diseases. The purpose of this report was to investigate transgenic GDNF expression at different time points post AAV mediated GDNF intramuscular delivery. An AAV vector was constructed to encode a recombinant fusion of GDNF tagged with a FLAG sequence at the C-terminal (AAV-GDNF) to distinguish it from its endogenous counterpart. A single intramuscular injection of AAV-GDNF led to substantial expression of transgenic GDNF which remained for at least 10 months in transduced gastrocnemius muscle. This transgenic GDNF was distributed in a large number of myofibers, mainly in the vicinity of the sarcolemma and predominantly concentrated at the sites of neuromuscular junctions (NMJs). Furthermore, transgenic GDNF, but not beta-galactosidase expressed as a control, was detected in the motoneurons that projected axons to the injected muscles, thus, indicating retrograde axonal transportation of the transgenic GDNF. This study provides a basis for a strategy of intramuscular AAV-GDNF delivery to protect motoneurons as a possible means of ALS treatment., (Copyright 2002 Elsevier Science Ireland Ltd and the Japan Neuroscience Society)

Choline acetyltransferase activities were measured in various forebrain regions 3, 7, 14, 21 and 28 days after bilateral lesions of the pedunculopontine nucleus area with ibotenic acid. The decrease was predominant in the ventral tegmental area and medial thalamus (especially at the caudal level). The decrease recovered as rapidly as 21 days after the lesions. It is concluded that the ascending cholinergic pedunculopontine projection is topographically organized within the thalamus and it appears that the effect of the experimental destruction of the projection recovered within a month.

Pedunculopontine nucleus areas were lesioned bilaterally in the rat by local injection of kainic acid. When rats so treated were tested for active avoidance behavior in shuttle boxes we found that their avoidance acquisition was completely abolished, whereas their intertrial locomotor activity and escape behavior were not affected. In the lesioned rats, choline acetyltransferase activity in the medial thalamus and substantia nigra decreased, but not in the lateral thalamus, hippocampus, or cerebral cortex. These findings suggest that the cholinergic pedunculopontine-medial thalamus projection plays an important role in memory acquisition in the rat.