Biomedical subjects

Irving M Reti

Publications and source records attributed to Irving M Reti.

6 recordsLinked to original sources

PubMed2004

Anxiety and depressive disorders and the five-factor model of personality: a higher- and lower-order personality trait investigation in a community sample.

We describe in detail normal personality traits in persons with psychiatrist-ascertained anxiety and depressive disorders in a general population sample. We investigated Revised NEO Personality Inventory traits in 731 community subjects examined by psychiatrists with the Schedules for Clinical Assessment in Neuropsychiatry. All of the lifetime disorders of interest (simple phobia, social phobia, agoraphobia, panic disorder, obsessive-compulsive disorder (OCD), generalized anxiety disorder, major depressive disorder (MDD), and dysthymia) were associated with high neuroticism. Social phobia, agoraphobia, and dysthymia were associated with low extraversion, and OCD was associated with high openness to experience. In addition, lower-order facets of extraversion (E), openness (O), agreeableness (A), and conscientiousness (C) were associated with certain disorders (specifically, low assertiveness (E) and high openness to feelings (O) with MDD, low trust (A) with social phobia and agoraphobia, low self-discipline (C) with several of the disorders, and low competence and achievement striving (C) with social phobia). Neuroticism in particular was related to acuity of disorder. Longitudinal study is necessary to differentiate state versus pathoplastic effects.

Adult↗

PubMed2003

Opiate withdrawal induces Narp in the extended amygdala.

The negative affective states associated with drug withdrawal produce long-lasting behavioral effects thought to play a central role in the development and maintenance of dependence. However, little is known about the molecular mechanisms mediating the long-term effects of drug withdrawal. Neuronal activity-regulated pentraxin (Narp) is a secreted neuronal immediate early gene (IEG) product that regulates AMPA receptor clustering at synapses. As both IEGs and changes in AMPA receptor trafficking mediate enduring forms of neuronal plasticity, we have assessed whether Narp could be involved in the molecular adaptations accompanying drug withdrawal. To this end, we checked the effect of opiate withdrawal on Narp expression in the extended amygdala, a brain region closely linked to the aversive effects of drug withdrawal. We found a marked increase in the number of Narp-positive cells in this region following opiate withdrawal triggered by either low doses of opiate antagonists or by 'natural withdrawal', removal of the morphine pellets used to induce dependence. In contrast, Arc, another 'effector' IEG, was not induced by opiate withdrawal. As expected, pretreatment of animals with clonidine, which blocks opiate withdrawal, suppresses Narp induction in this paradigm. These results implicate Narp in mediating the long-term, aversive behavioral effects induced by opiate withdrawal.

Amygdala↗

PubMed2002

Influences of parenting on normal personality traits.

There is a considerable literature linking aspects of experienced parenting to later personality disorders. Because dimensionally measured personality disorders are associated with variations in normal personality traits, it is important to understand the contribution of parenting experienced in childhood to later normal personality traits. In this report, 742 community-based individuals, subjects from the Hopkins Epidemiology of Personality Disorders Study, were assessed for normal personality traits, as measured by the Revised NEO Personality Inventory (NEO-PI-R) and the Temperament and Character Inventory (TCI), and for parental behavior experienced as children, as measured by the Parental Bonding Instrument (PBI). The PBI dimensions were significantly, but moderately, correlate with measures of normal personality, the strongest associations being with the NEO-PI-R factors, neuroticism and conscientiousness, and with the TCI factors, self-directedness and harm avoidance. Subjects who reported lower parental care and higher parental intrusiveness were more likely to be higher in neuroticism, lower in conscientiousness, lower in self-directedness, and higher in harm avoidance. Also, trends emerged suggesting both parent-specific and gender-specific differences in the relationship between the PBI dimensions and normal adult personality traits. As variations in normal personality traits are associated with dimensionally measured personality disorders, it is conceivable that the role of parenting in later personality disorder may be mediated by associations between parenting and normal personality traits.

Adult↗

PubMed2002

Prominent expression of Narp in central vestibular pathways: selective effect of labyrinth ablation.

Recent in vitro studies demonstrated that Narp, a secreted immediate early gene (IEG) product, induces AMPA receptor clustering. Accordingly, Narp has been implicated in mediating activity-dependent changes in synaptic efficacy. To help define the role of Narp in vivo, we conducted immunohistochemical studies of Narp in rat brain. Unexpectedly, we found robust Narp expression in several discrete areas linked to the vestibular system: the anterodorsal nucleus (ADN) of the thalamus, which relays head orientation information to the cortex, the lateral vestibulospinal (Deiters') nucleus and Purkinje cells in the flocculonodular lobe of the cerebellum. Although strong Narp expression in Deiters' nucleus and the cerebellum was present consistently, Narp expression in the ADN displayed a high degree of variability among animals. To check if this variability in ADN Narp expression reflects its dependence on fluctuating levels of vestibular input, we monitored Narp immunostaining following bilateral labyrinth ablation. This procedure significantly suppressed Narp immunostaining in the ADN, indicating that it is stimulated by naturally occurring vestibular input. In contrast, labyrinth ablation did not affect Narp staining in Deiters' nucleus or the flocculonodular lobe of the cerebellum, presumably because these areas are driven by inputs from multiple systems. As previous studies implicate Narp in synaptic plasticity, these findings suggest that this IEG may mediate ongoing adjustments in synaptic strength or connectivity in several pathways linked to the vestibular system.

Animals↗

PubMed2002

Prominent Narp expression in projection pathways and terminal fields.

Narp (neuronal activity regulated pentraxin) is a secreted immediate early gene product that is induced by synaptic activity. Recent studies have indicated that Narp may be an extracellular aggregating factor for AMPA receptors. Immunohistochemical studies have revealed prominent expression of Narp in the mossy fiber pathway of the dentate gyrus, suggesting it may be released pre-synaptically. However, in vitro studies using recombinant Narp indicate that Narp may act when expressed by either pre- or post-synaptic elements. To help define Narp's mode of action, we have examined its localization in the habenula-interpeduncular pathway which also displays robust Narp expression. Focusing on this pathway as well as hippocampal and cortical Narp expression, we found prominent Narp staining in projection pathways and terminal fields. In contrast, Narp expression in dendrites was minimal in these neuronal populations. These findings indicate that, under physiological conditions, Narp is targeted to the synapse from pre- rather than post-synaptic elements. Our results also suggest that future studies focusing on these projection pathways that express high levels of Narp, in vivo, may help to understand the regulation and function of endogenous Narp.

Animals↗

PubMed2002

Selective expression of Narp, a secreted neuronal pentraxin, in orexin neurons.

Recent studies have provided compelling evidence demonstrating that orexin (also known as hypocretin) neurons play a central role in the pathophysiology of narcolepsy. However, targeted deletion of orexin does not fully mimic the functional deficits induced by selective ablation of these neurons; implying that other secreted signaling molecules expressed in these neurons mediate key aspects of their function. In this study, we demonstrate that orexin neurons display robust expression of neuronal activity-regulated pentraxin (Narp), a secreted neuronal pentraxin, implicated in regulating clustering of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptors. Furthermore, we have found that hypothalamic melanin-concentrating hormone (MCH) neurons, which form a peptidergic pathway thought to oppose the effects of the orexin system, express another neuronal pentraxin, NP1. Thus, these findings suggest that these pathways utilize neuronal pentraxins, in addition to neuropeptides, as synaptic signaling molecules.

Animals↗