G. Gvaryahu

The relationship between neural alterations and behavioral deficits after prenatal exposure to heroin.

The present studies employ multitudinous approaches in order to overcome the methodological obstacles in the understanding of the relationship between neurochemical alterations and behavioral deficits induced by heroin during prenatal development. Mice were exposed prenatally to heroin via daily subcutaneous injections of 10 mg/kg, on gestation days 9‐18. At age 50 days, the heroin‐exposed offspring displayed behavioral deficits as assessed in the eight‐arm and Morris mazes, pointing to possible alteration in the septohippocampal cholinergic innervations. Biochemically there was increased presynaptic activity of these innervations as attested to by the increased [3H]hemicholinium‐3 (HC‐3) binding sites and by K+‐stimulated inositol phosphate (IP) formation. Postsynaptically, there was global hyperactivation along the different components of the nerve conduction cascade, including an increase in M1 muscarinic receptor Bmax, a general increase in G‐proteins (GP) including the most relevant, Gq subtype, and an increase in IP formation and in basal protein kinase C (PKC) activity. However, there was desensitization of PKC activity in response to cholinergic agonist in the heroin‐exposed offspring. Transplantation of normal embryonic cholinergic cells to the impaired hippocampus reserved the behavioral deficits and both the pre‐ and postsynaptic hyperactivity and resensitized PKC activity.

Testosterone and adiposity in the chicken: The effect of breed and sex

The leaning role, previously suggested for testosterone in chickens, was tested in males and females of fatty and lean breeds. The breeds used were the White Leghorn (WL), of which the male is very lean, and the White Giant (WG) and the White Cornish X White Rock (WCWR), in which both sexes accumulate fat. Castration of WL males induced adiposity and replacement therapy with testosterone propionate (TP) reduced the fat to normal. However, in males of the fatty breeds, neither castration nor TP administration had any effect on adiposity. Similarly, long-term supplementation of a high dose of TP had no effect on the level of adiposity in females of both the heavy and the light breeds. Thus, the leaning effect found for testosterone in the WL male is not a general phenomenon in chickens but rather a specific response of the WL male.

Pecking: another measurement for filial attachment in group-reared domestic fowl chicks

Abstract This study examines different types of attachment measurements and pecking behavior in group-reared domestic chicks imprinted to a silent imprinting object. Immediately upon arriving from the hatchery, groups of heavy strain chicks were imprinted to a colored foam rubber ball for 72 h. The bond between these chicks and the imprinting object was then tested from 8 days until 5 weeks of age. Three days of imprinting sessions demonstrated that a strong attachment could be formed between the imprinted chicks and the imprinting object. In both experimental and control groups, the number of pecks was found to be significantly correlated with the latency measurements. It is, therefore, reasonable to consider the number of pecks of the imprinting object as another measurement for filial attachment.