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Biomedical subjects

H Jonathan Polan

Publications and source records attributed to H Jonathan Polan.

7 recordsLinked to original sources
PubMed2006

DRD2 C957T polymorphism interacts with the COMT Val158Met polymorphism in human working memory ability.

The C957T polymorphism in the dopamine D2 receptor (DRD2) gene and the Val158Met polymorphism in the Catechol-O-Methyl-Transferase (COMT) gene affect dopamine transmission and have been found to be associated with schizophrenia. Since DRD2 in mice and the COMT gene in humans modulate working memory, we examined the relationship and possible interaction of both polymorphisms to working memory performance in 188 healthy adults. Subjects having the DRD2 C/C allele showed the poorest performance in a word serial position test. Moreover, the effect of the C957T genotype was strengthened when interaction with the COMT Val158Met polymorphism was included in the analysis. We propose that an interaction of the DRD2 C957T and COMT Val158Met may be involved in the generation of some working memory deficits in schizophrenia.

Adolescent↗
PubMed2006

Transient and selective overexpression of dopamine D2 receptors in the striatum causes persistent abnormalities in prefrontal cortex functioning.

Increased activity of D2 receptors (D2Rs) in the striatum has been linked to the pathophysiology of schizophrenia. To determine directly the behavioral and physiological consequences of increased D2R function in the striatum, we generated mice with reversibly increased levels of D2Rs restricted to the striatum. D2 transgenic mice exhibit selective cognitive impairments in working memory tasks and behavioral flexibility without more general cognitive deficits. The deficit in the working memory task persists even after the transgene has been switched off, indicating that it results not from continued overexpression of D2Rs but from excess expression during development. To determine the effects that may mediate the observed cognitive deficits, we analyzed the prefrontal cortex, the brain structure mainly associated with working memory. We found that D2R overexpression in the striatum impacts dopamine levels, rates of dopamine turnover, and activation of D1 receptors in the prefrontal cortex, measures that are critical for working memory.

Adenylyl Cyclases↗
PubMed2006

Attachment and psychopathology in a community sample.

The Structured Clinical Interview for DSM-III-R (SCID-I) and the Adult Attachment Interview (AAI) were administered to 60 women participating in a study (n=226) of mother-child interaction. These women were not referred to the study for psychiatric care. The 60 women interviewed with the AAI were selected from the first 190 women who completed the SCID-I, so that 30 received a diagnosis and 30 did not. Analyses indicated that psychopathology diagnoses were associated significantly with mental representations of attachment classified in the AAI. The non-autonomous groups had increased likelihood of SCID diagnosis, compared to the autonomous group. While 32% of women with autonomous AAI transcripts received SCID diagnoses, 63% of women with Dismissing, 100% of woman with Preoccupied, and 65% of women with Unresolved transcripts received diagnoses. Secondary analyses indicated that Dismissing classifications were associated with Axis I diagnoses and Preoccupied classifications with affective disorders. Of note was that among women with Unresolved classifications, underlying secure attachment was associated with low risk of psychopathology, while underlying anxious attachment was associated with elevated risk of diagnosis. These findings support the premise from attachment theory that early relationships affect patterns of interpersonal expectations and behavior and affect regulation.

Adjustment Disorders↗
PubMed2005

Guidance and differentiation of maternally directed orienting behaviors: probing the origins of filial attachment.

Newborn rats seek and attain contact with their mothers by orienting and primitive locomotor behaviors called maternally-directed orienting behaviors (MDOBs). By 2 days of age MDOBs are elicited specifically by maternal features and are heightened by a period of acute separation from the mother. This behavioral regulation by the mother's presence suggests an early form of filial attachment. To probe for other evidence of filial attachment, two aspects of the controls of MDOBs were investigated: (1) whether MDOBs are goal-corrected in relation to the dam's position and (2) whether the performance of MDOBs can be separated from that of suckling. It was found that, during the first 2 days after birth, MDOBs maintained the pup's ventrum-to-ventrum contact with the dam regardless of her position, suggesting that they are goal-corrected. Evidence was not found for independent controls of nipple grasping (NG), the behavior that initiates suckling, and MDOBs during the first two postnatal days.

Animals↗
PubMed2005

Toward a neurobiology of psychotherapy: basic science and clinical applications.

Psychotherapy is used commonly to treat a variety of mental illnesses, yet surprisingly little is known about its biological mechanisms especially in comparison with pharmacotherapy. In this review we survey the current knowledge about changes in brain function following psychotherapeutic intervention that are detectable with current neuroimaging techniques. We also consider the possible role for neuroimaging in refining clinical diagnoses and predicting treatment outcome, which would benefit both clinical decision-making and the cognitive neuroscience of psychotherapy.

Consciousness↗
PubMed2003

Characterizing the functional significance of the neonatal rat vibrissae prior to the onset of whisking.

The present series of experiments assessed how information from the whiskers controls and modulates infant rat behavior during early learning and attachment. Passive vibrissal stimulation can elicit behavioral activity in pups throughout the first two postnatal weeks, although orienting to the source of stimulation is evident only after ontogenetic emergence of whisking. In addition, while pups were capable of demonstrating learning in a classical conditioning paradigm pairing vibrissa stimulation with electric shock, no corresponding changes were detected in the anatomy of the barrel cortex as determined by cytochrome oxidase (CO) staining. Finally, the role of whiskers in a more naturalistic setting was determined in postnatal day (PN)3-5 and PN11-12 pups. Our results showed that both nipple attachment and huddling were disrupted in whisker-clipped PN3-5 pups but only marginally altered in PN1I 1-12 pups. Together, these results suggest that the neonatal whisker system is behaviorally functional and relevant for normal mother-infant interactions, though it lacks the sophistication of a mature whisker system that evokes very specific and directed responses.

Animals↗