An experimental analysis of the origins of somatostatin-like immunoreactivity in the dentate gyrus of the rat

摘要: In previous studies, fibers demonstrating somatostatin-like immunoreactivity were observed in the outer half of molecular layer dentate gyrus rat and monkey. They occupy same region as those perforant pathway that originates entorhinal cortex. Numerous somatostatin immunoreactive neuronal cell bodies also hilar region, though stained axonal profiles could not be followed from these cells into layer. present study, several experimental procedures employed to determine origin somatostatin-positive Transection path resulted such characteristic changes shrinkage sprouting AChE-positive fibers. There was no apparent decrease, however, density fact, since occupied a narrower band shrunken layer, their appeared greater. Injections kainic acid produced lesion neurons, including positive for somatostatin. loss, there marked reduction somatostatin-immunoreactive ipsilateral with detectable homotopic contralateral The distribution AChE fibers, which presumably have an extrinsic origin, altered by treatment. final series experiments, retrograde tracer wheat germ agglutinin-horseradish peroxidase (WGA-HRP) injected sections prepared simultaneous demonstration immunoreactivity. Somatostatin-positive neurons WGA-HRP reaction product primarily but few double-labeled seen area side. These studies indicate population intrinsic located polymorphic projects A similar, very much smaller, projection extends gyrus. Taken together, projections appear account