Early brain insult and cognition: A comparison of malnutrition and hypothyroidism

Abstract

The effects of two biological insults, hypothyroidism and malnutrition, incurred during pre- and postnatal development were compared using a newly developed test of observational learning in rats. Whereas early hypothyroidism produced a significant impairment in observational learning in recovered rats, no indication of any impairment was observed in rats recovered from early malnutrition. These results are important in that they demonstrate that tests of advantageous learning such as observational learning are sensitive to the kinds of early biological insult that lead to permanent cognitive impairment in humans. Moreover, these data further support the concept that the cognitive impairment observed during periods of malnutrition in humans and animals is not permanent.

Developmental Binge Exposure to Ethanol and Artificial Rearing Do Not Affect the Social Transfer of Diet Preference

“…A review of the literature indicates that the enhancement of diet preference remains robust across various methodologies, but that procedural aspects may make a difference in detecting group differences (Alvarez et al, 2001;Burton et al, 2000;Galef, 1986;Galef and Whiskin, 1998;Strupp and Levitsky, 1983;Winocur, 1990). The degree of preference in this study was not as high as that reported by some but is consistent with others (e.g., Burton et al, 2000).…”

“…Rats are especially vulnerable to brain damage and long-lasting behavioral deficits induced by heavy binge exposure to ethanol during the early postnatal period (Guerri, 1998;Tran et al, 2000;West and Hamre, 1985), as used in this study. Moreover, Strupp and Levitsky (1983) and have argued that tests of "advantageous learning" are particularly sensitive to early biological insult, assessing the acquisition of information that is not driven by learned reinforcement or immediate survival needs (e.g., water escape). In other words, although immediately inconsequential to survival, encoding food odors on a conspecific's breath may provide an advantage in future selections of safe foods.…”

PKU, Learning, and models of mental retardation

“…The studies presented here on experimental phenylketonuria stemmed from our earlier research on the long-term effects of early malnutrition on cognition (Strupp & Levitsky, 1983). Both a review of the animal learning literature and our own work suggested to us that a distinction could be made between those tests which have revealed unconfounded learning deficits attributable to biological insults (e.g., concurrent malnutrition and early hypothyroidism) and those tests which have not.…”

“…Levitsky, 1983). To gain further verification of the sensitivity of the advantageous learning model of human cognitive deficits, we examined the long-term effects of neonatal "phenylketonuria" on cognition, using two different tests of advantageous learning: observational learning and latent learning.…”

The Effects of Thyroid Hormone Level and Action in Developing Brain: Are These Targets for the Actions of Polychlorinated Biphenyls and Dioxins?

“…The data for hypothyroidism cited in this table are from the following references:Eayrs and Levine, 1963;Essman et al, 1968; Davenport et al, 1976a,b;Schalock et al, 1979;Johanson, 1980;Johanson et al, 1980;Narayanan et al, 1982;Strupp and Levitsky, 1983;Overstreet et al, 1984;Comer and Norton, 1985;Adams et al, 1989;Anthony, 1990;Anthony et al, 1993. The following references were cited for hyperthyroidism: Davenport et al, 1975;Stone and Greenough, 1975;Sjoden and Soderberg, 1976.…”