| Abstract: | The intermediate and medial part of the hyperstriatum ventrale (IMHV) is a memory system in the chick forebrain in which certain learning-related changes occur after imprinting. We have enquired whether NADPH-diaphorase, a presumed marker for nitric oxide synthase, is present in sections through the IMHV of chicks, either trained with an imprinting stimulus or dark-reared. Very few NADPH-d-positive cells were found in the IMHV(0.37 ± 0.07S.E.M. cells per0.3mm× 0.9mm sampling), in contrast to the palaeostriatum augmentatum (PA)(19.47 ± 0.77). Some stained cells in the PA were closely associated with blood vessels. The results do not support the hypothesis that learning-related changes in the IMHV depend on nitric oxide acting as a retrograde neuronal messenger. |
