Distinctive messages in infant-directed lullabies and play songs.

Mothers were recorded singing a song of their choice in both a lullaby style and a play-song style to their 6-month-olds. Adult raters identified the play-song-style and lullaby-style versions with 100% accuracy. Play-song-style renditions were rated as being more brilliant, clipped, and rhythmic and as having more smiling and more prominent consonants. Lullaby-style renditions were characterized as being more airy, smooth, and soothing. Adults observed videotapes (without sound) of 6-month-olds listening to alternating lullaby-style and play-song-style trials and performed at above chance levels when determining which music the infants were hearing. Coding analyses revealed that infants focused their attention more toward themselves during lullaby-style trials and more toward the external world during play-song-style trials. These results suggest that singing may be used to regulate infants' states and to communicate emotional information.

Specific detection of noradrenaline in the rat brain by using antibodies.

Noradrenaline (NA) was conjugated to different protein carriers with glutaraldehyde. During the catecholamine conjugate synthesis, precautions were taken in order to preserve the structure of NA. Anti-NA antibodies were raised in rabbits and tested using a modified enzyme-linked immunosorbent assay and immunocytochemistry. The most immunoreactive antigen was found to be the reduced NA conjugate. The octopamine conjugate was recognized by the NA antiserum 16 X less than the reduced NA conjugate. The other conjugates, dopamine, L-dihydroxyphenylalanine and adrenaline were poorly recognized by the anti-NA antibodies. A good correlation was found between results obtained using the in vitro enzyme-linked immunosorbent assay and immunocytochemistry.

Anti-acetylcholine antibodies and first immunocytochemical application in insect brain.

A specific immunological approach was developed to enable acetylcholine (ACh) to be visualized in biological tissues. A variety of ACh-like immunogens were synthesized, and injected into rabbits. Antibody specificity was tested using an enzyme-linked immunosorbent assay (ELISA) method. The most immunoreactive ACh derivative was found to be choline-glutaryl-lysine. A mixture of allyl alcohol and formaldehyde was found to be the best fixative of ACh in tissues. The specificity of this antibody recognition was tested in vitro and in immunochemistry. There was excellent agreement between the in vitro results and the ACh staining. Moreover, visualization using these anti-ACh antibodies appeared identical to the results using anti-choline acetyltransferase antibodies.

Antisera against the indolealkylamines: tryptophan, 5-hydroxytryptophan, 5-hydroxytryptamine, 5-methoxytryptophan, and 5-methoxytryptamine tested by an enzyme-linked immunosorbent assay method.

Antisera were raised against tryptophan, 5-hydroxytryptophan, 5-hydroxytryptamine, 5-methoxytryptophan, and 5-methoxytryptamine, by conjugating each molecule to bovine serum albumin and to human serum albumin via glutaraldehyde, in such a way as to preserve the original part. Antibody specificity was tested with the enzyme-linked immunosorbent assay method. The specificity of each anti-indolealkylamine-glutaraldehyde antibody was established with competition experiments by using an adsorbed immunogenic conjugate and indolealkylamines either free or conjugated with poly-L-lysine. The nonconjugated compounds were poorly recognized. In the same way, the nonreduced conjugates always appeared less immunoreactive than the reduced ones. Calculated from the specificity study of each antiserum, the cross-reactivity ratios were found to be smallest for the most immunoreactive conjugates. Thus, a specific immune response was defined for each compound belonging to the same metabolic pathway.

Antisera against small neurotransmitter-like molecules.

Antisera were produced against three types of small neurotransmitter-like molecules: indolealkylamines, catecholamines and amino acid derivatives such as GABA. The specificity of the antisera were evaluated using radioimmunological or immunoenzymatic competition tests between a radiolabelled ligand or conjugated hapten, and analog molecules from the same metabolic pathway. The antibody site was characterized by the ratios of cross-reactivity and the affinity constants. On the basis of these in vitro studies, each immune response was found to be specific for the target molecule.

Antisera against catecholamines: specificity studies and physicochemical data for anti-dopamine and anti-p-tyramine antibodies.

Antibodies against dopamine and p-tyramine were raised in rabbits. The two catecholamines were conjugated to albumin by glutaraldehyde. The specificity of the antibodies was established by equilibrium dialysis competition experiments using an immunoreactive tritiated derivative synthesized by coupling dopamine or p-tyramine to N-alpha-acetyl-L-lysine N-methylamide with glutaraldehyde. Hence, these radiolabelled ligands mimicked the antigenic determinant of conjugated immunogens. A comparison of the data obtained showed the high specificity of each antiserum for its hapten coupled by glutaraldehyde. The anti-dopamine antibodies recognized dopamine-glutaraldehyde but not p-tyramine-glutaraldehyde. The opposite occurred for the anti-p-tyramine antibodies. A slight modification of the molecular structure provided the opportunity for a specific response against that molecule. But this difference was more important when related to the hapten region where the antibody affinity was maximal. The cross-reactivity was observed to be more important dopamine and p-tyramine than between dopamine and noradrenaline on the one hand and between p-tyramine and dopamine than p-tyramine and octopamine on the other hand.