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Biomedical subjects

M R Rosenzweig

Publications and source records attributed to M R Rosenzweig.

At least 19 recordsLinked to original sources
PubMed2000

The New Immigrant Survey Pilot (NIS-P): overview and new findings about U.S. legal immigrants at admission.

This paper provides an overview of the New Immigrant Survey Pilot (NIS-P), a panel survey of a nationally representative sample of new legal immigrants to the United States based on probability samples of administrative records of the U.S. Immigration and Naturalization Service (INS). The NIS-P links survey information about immigrants' pre- and post-immigration labor market, schooling, and migratory experiences with data available from INS administrative records, including the visa type under which the immigrant was admitted. Results indicate that the procedures followed for locating, interviewing, and reinterviewing respondents yielded representative samples of new legal immigrants and high-quality data. On the basis of data obtained from the first round of the survey, we present new information never before available on the schooling and language skills of new immigrants and their earnings gains from immigration.

Adolescent↗
PubMed1999

Continuity and change in the development of psychology around the world.

A survey conducted in 1998 by the International Union of Psychological Science showed that psychology is continuing to grow and expand around the world. At the same time, psychology faces severe challenges, including these: (a) responding to increased demands for accountability, (b) developing research that will be applicable to such problems as resolving and alleviating ethnic conflicts, (c) gaining an appropriate classification for psychology among the disciplines, and (d) helping meet the needs of the "knowledge society." Taking stock of psychology's present resources and state of development should be a helpful exercise in planning for further development. Some proposals are suggested and more are welcomed to deal with the challenges to be faced in the international development of psychology.

Humans↗
PubMed1998

The changing skill of new immigrants to the United States: recent trends and their determinants.

"The objective of this paper is to describe and understand the determinants of changes in the number and quality of new legal immigrants to the United States over the last 25 years. Our main interest is in understanding the behavioral response of potential immigrants to changes in the U.S. immigration law regime (as well as in the origin-country determinants of demand for immigration to the United States) and how these affect and have affected the skill composition of immigrants.... [The authors] assembled a new data set based on annual INS records of all new, legal immigrants over the period 1972 through 1995.... Inspection of our new data indicates that since the mid 1980s the average skill of new, U.S. legal immigrants has been rising relative to that of the U.S. population. An econometric analysis of a panel of country-specific measures of the skill of immigrants based on these data over the period 1972-1992 indicates that these changes are due in part to changes in immigration law and to the overall rise in the real purchasing power of countries outside the United States."

Americas↗
PubMed1997

Evidence for localized and discrete roles for enkephalins during memory formation in the chick.

This study examined effects on memory formation produced by [Leu]enkephalin and [Met]enkephalin administration in 2 regions of the 2-day-old chick brain involved in memory formation: the intermediate medial hyperstriatum ventrale (IMHV) and the lobus parolfactorius (LPO). Basal concentrations of endogenous [Leu]enkephalin and [Met]enkephalin were determined for 5 brain regions, and effects of 1-trial peck-avoidance training on enkephalin concentrations were examined in the IMHV and LPO. [Leu]enkephalin was amnestic when administered in the IMHV but not in the LPO. In contrast, [Met]enkephalin may be amnestic when administered in the LPO but not in the IMHV. Training decreased [Met]enkephalin concentration in the LPO but not in the IMHV. Training had no effect on [Leu]enkephalin concentration in either the IMHV or the LPO. Thus, amnestic effects of [Leu]- or [Met]enkephalin administration are brain-region specific. Regional activity of endogenous [Met]enkephalin during memory formation is consistent with localized amnestic effects produced by [Met]enkephalin administration.

Age Factors↗
PubMed1996

Psychobiology of plasticity: effects of training and experience on brain and behavior.

Supporting Hebb's 1949 hypothesis of use-induced plasticity of the nervous system, our group found in the 1960s that training or differential experience induced neurochemical changes in cerebral cortex of the rat and regional changes in weight of cortex. Further studies revealed changes in cortical thickness, size of synaptic contacts, number of dendritic spines, and dendritic branching. Similar effects were found whether rats were assigned to differential experience at weaning (25 days of age), as young adults (105 days) or as adults (285 days). Enriched early experience improved performance on several tests of learning. Cerebral results of experience in an enriched environment are similar to results of formal training. Enriched experience and training appear to evoke the same cascade of neurochemical events in causing plastic changes in brain. Sufficiently rich experience may be necessary for full growth of species-specific brain characteristics and behavioral potential. Clayton and Krebs found in 1994 that birds that normally store food have larger hippocampi than related species that do not store. This difference develops only in birds given the opportunity to store and recover food. Research on use-induced plasticity is being applied to promote child development, successful aging, and recovery from brain damage; it is also being applied to benefit animals in laboratories, zoos and farms.

Animals↗
PubMed1996

Aspects of the search for neural mechanisms of memory.

The search for neural mechanisms of memory has been under way for more than a century. The pace quickened in the 1960s when investigators found that training or differential experience leads to significant changes in brain neurochemistry, anatomy, and electrophysiology. Many steps have now been identified in the neurochemical cascade that starts with neural stimulation and ends with encoding information in long-term memory. Applications of research in this field are being made to child development, successful aging, recovery from brain damage, and animal welfare. Extensions of current research and exciting new techniques promise novel insights into mechanisms of memory in the decades ahead.

Adolescent↗
PubMed1995

Norepinephrine and neural plasticity: the effects of xylamine on experience-induced changes in brain weight, memory, and behavior.

The hypothesis that norepinephrine (NE) is critically involved in neural plasticity was tested by administering xylamine, (N-2-chloroethyl-2-methylbenzylamine, 50 mg/kg ip) a noradrenergic neurotoxin, to young rats prior to maze training or environmentally enriched housing. In saline-treated rats, exposure to enriched conditions significantly increased the weight of occipital, dorsal, and ventral cortices and the remaining brain compared to individually housed rats. In xylamine-treated rats, only the weight of dorsal cortex increased with exposure to enriched conditions. Maze training increased the weight of dorsal and ventral cortices of saline-treated animals compared to rats without training. However, maze training did not increase brain weights of xylamine-treated rats compared to those of xylamine-treated controls. Xylamine treatment did not reduce brain weights of individually housed animals. Behavior was assessed with spatial learning on a holeboard maze and with investigatory measures of locomotion and hole investigation in a multicompartmented arena. Spatial working memory on the holeboard maze was not impaired by xylamine treatment. Arena measures were affected mainly by the housing condition, testing condition, and strain of rat (Long-Evans vs Wistar), with only subtle changes in behavior induced by NE depletion. Thus, an intact NE projection was required for environmentally dependent changes in cortical morphology. In contrast, measures of memory and investigatory behavior were not dependent on an intact noradrenergic projection. These results support the hypothesis that NE facilitates selective neuronal changes, and that the impairment in cortical weight gain does not results from a general impairment of growth or a secondary response to reduced exploration and activity.

Animals↗
PubMed1995

Protein kinase inhibitors disrupt memory formation in two chick brain regions.

The amnesic effects of protein kinase inhibitors (H-7, HA-156, TFP, W-9, and W-13) on memory formation for a one trial peck-avoidance task in chicks were investigated with bilateral and unilateral injections into either the left or the right intermediate medial hyperstriatum ventrale (IMHV) or the left or right lobus parolfactorius (LPO). All five inhibitors injected bilaterally 5 min pretraining into either the IMHV or LPO or unilaterally into the left IMHV produced amnesia. Unilateral injections into the right IMHV did not produce amnesia. Unilateral injections of W-9 or W-13 into the left but not the right LPO produced amnesia, H-7, HA-156, or TFP did not produce amnesia when injected unilaterally into either the left or right LPO. The time of onset of amnesia produced by injecting TFP and W-13 into the LPO occurred 45 min after training, whereas H-7 produced amnesia significantly later (90 min after training). Amnesia induced by TFP, W-13, and H-7 injected into the LPO occurred significantly later than amnesia produced when these agents were injected into the IMHV. Together these data suggest that the IMHV and LPO process memory sequentially using various protein kinase activities.

Animals↗
PubMed1995

Protein kinase C inhibitor chelerythrine disrupts memory formation in chicks.

Chelerythrine (CHELE), a specific, potent protein kinase C (PKC) inhibitor, disrupts memory formation for a one-trial peck-avoidance task. Three predictions were made about how CHELE, injected into chick brain near the time of training, would affect memory formation, based on previous work with two classes of protein kinase inhibitors (M. R. Rosenzweig et al., 1992; P. A. Serrano et al., 1994) and the in vitro inhibition of PKC by CHELE: (a) CHELE, injected into the intermediate medial hyperstriatum ventrale, would significantly impair memory formation; (b) the amnestic dose would be approximately 10 nmol; (c) CHELE would not produce amnesia for about 45 min after training, but significantly impair memory by 60 min. Experimental tests confirmed each prediction. This study adds to evidence that PKC activity is part of a cascade of neurochemical events initiated by learning and that PKC activity shortly after training is necessary for long-term memory.

Alkaloids↗
PubMed1995

Sisters, siblings, and mothers: the effect of teen-age childbearing on birth outcomes in a dynamic family context.

"In this paper, we formulate a statistical model of dynamic intrafamily investment behavior incorporating endowment heterogeneity and heritability. We use the model's estimates to evaluate alternative estimation procedures that have exploited family and kinship data to obtain estimates of the determinants of human capital." The sequential decision-making framework developed is applied to data on birthweight and gestation of children born to mothers surveyed in the U.S. National Survey of Labor Market Experience youth cohort. "The empirical results imply that the least restrictive statistical formulation, consistent with dynamic behavior and heterogeneity among siblings, fits the data best. All of the estimation procedures that control for a family-specific endowment indicate, however, that the biological effect of having a birth at younger ages is to marginally increase birthweight and to increase fetal growth."

Age Factors↗
PubMed1995

Do immigrants screened for skills do better than family reunification immigrants?

"It is sometimes thought that immigrants [to the United States] who are screened for occupational skills are likely to become more productive Americans than immigrants who gain admission on the basis of family ties to native-born U.S. citizens or to previous immigrants. However, the expected differential may be small or nonexistent because: 1) kinship immigrants have access to family networks; 2) whereas employers may screen for short-term productivity, family members may screen for long-term productivity; and 3) native-born U.S citizens who sponsor spouses may be particularly adept at screening for long-term success. Longitudinal data on the 1977 immigrant cohort is used to compare initial and longer-term occupational outcomes among employment and kinship immigrants. Results indicate a narrowing of the differential, due both to higher rates of occupational downgrading among employment immigrants and of occupational upgrading among kinship immigrants."

Americas↗
PubMed1994

Differential effects of protein kinase inhibitors and activators on memory formation in the 2-day-old chick.

Thirteen protein kinase inhibitors (PKIs) were investigated in chicks for their in vitro effects on PKC activity and for their in vivo effects on memory formation for a peak-avoidance task. Amnesia occurred by 15-30 min post-training when agents that inhibit primarily Ca2+/calmodulin were injected into brain. Amnesia occurred by 60 min post-training when agents that inhibit PKC-, PKA-, and/or PKG-dependent protein kinases, but not Ca2+/calmodulin, were injected. Enhancement of memory formation was accomplished by injecting bradykinin, but not forskolin. Both of these agents, however, attenuated the amnesia produced by H-7. These results are discussed as relevant neural processes involved in memory and synaptic plasticity.

Amnesia↗
PubMed1993

Short-term, intermediate-term, and long-term memories.

This paper focuses on the temporal dimension of memory formation and storage. Is the usual two-fold separation between short-term memory (STM) and long-term memory (LTM) sufficient to encompass all the phenomena of memory? The traditional view is that STM grades into LTM. Evidence for an intermediate-term memory (ITM) has been proposed by some investigators. We have used both rats and chicks to investigate the stages of memory formation. In this paper, the advantages of chicks for this type of research are briefly discussed. Using a paradigm that produces weak training, the retention function for control chicks appears to be made up of four successive components which we have interpreted as representing the memory buffer, STM, ITM, and LTM. In experiments using a variety of kinase inhibitors, we have obtained evidence that ITM and LTM depend on different classes of protein kinase activities. Agents that act on calcium/calmodulin kinase cause amnesia in the ITM range--15 to 30 min post-training. Another class of inhibitors act on one or more of the kinases PKA, PKC, or PKG and cause amnesia by 60 min post-training, so we interpret this group of inhibitors as inhibiting the formation of LTM. However, the three-stage model of memory may be over-simple. For example some agents including [Leu]enkephalin and MK801 cause amnesia 4 or more h after training.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1992

Kappa opioid receptor activity modulates memory for peck-avoidance training in the 2-day-old chick.

To examine the role of kappa opioid receptors in memory formation, 2-day-old chicks were injected intracerebrally with either the endogenous opioid peptide dynorphin(1-13), the highly kappa selective agonist U-50,488 or the kappa selective antagonist nor-binaltorphimine (nor-BNI), given one-trial peck-avoidance training, and tested 24 h later. Dynorphin(1-13) impaired memory in a dose dependent manner at 24 h test. Injection of U-50,488 caused a biphasic dose-dependent effect on memory; low doses caused a trend toward enhanced memory and high doses caused significant impairment. Conversely, injection of low doses of nor-BNI caused a trend toward memory impairment, and higher doses caused significant memory enhancement. The results indicate that memory formation for one-trial peck-avoidance training may be modulated by kappa opioid receptor activity.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1992

Comparative study of roles of the lobus parolfactorius and intermediate medial hyperstriatum ventrale in memory formation in the chick brain.

Two discrete areas of the chick brain, the intermediate medial hyperstriatum ventrale (IMHV) and lobus parolfactorius (LPO), were found to have different functions during the formation of memory for a 1-trial peck-avoidance paradigm. Glutamate, ouabain, and emetine, known to disrupt short-, intermediate-, and long-term memory when injected into the IMHV, were injected into the cerebellum and LPO. All amnestic agents investigated produced amnesia when injected into the IMHV; only one of these agents produced amnesia when injected into the LPO, and none of the agents produced amnesia when injected into the cerebellum. The chick brain was also found to exhibit hemispheric asymmetries: The left IMHV and LPO were more sensitive to the amnestic agents than their corresponding right structure. From these data, hypotheses for the roles of these structures during memory are proposed.

Animals↗