Effects of a new postnatal stress model on monoaminergic neurotransmitters in rat brains.

INTRODUCTION: Stress and environmental perturbations influence postnatal brain development and may account for the high disability rates of preterm survivors following intensive care treatment. This study aims to investigate the impact of early environmental factors on the monoaminergic neurotransmitter system in the developing rat brain by using an innovative neonatal stress model. MATERIALS AND METHODS: After birth, in the experimental groups newborn rats were separated from their mothers and exposed to different stressful stimuli four times a day on day P0 to P6 for 10 min each. To mimic intensive care treatment, the stress protocol applied environmental factors like bright light, noise, and low temperature alternating with pain and handling stress at day- and night-time in a varying sequence. The non-stressed control mothers and litters were left completely undisturbed until sacrificing on day P7 or P20. RESULTS: Brains of stressed animals revealed significantly higher levels of norepinephrine (NE) and dopamine (DA) as determined by HPLC-ED and electrochemical detection at day P7 as compared to controls. When returned to their mothers' undisturbed care, juvenile rats at day P20 still showed higher (yet statistically not significant) concentrations of NE and DA in brain. The stressed animals gained less weight with significantly lower body weights at day P7 compared to controls. Their mothers developed various forms of stressed behaviour. CONCLUSIONS: A novel animal model for postnatal intensive care stress was established leading to changes in brain monoamine levels of newborn rats, while undisturbed maternal care seems to moderate the stress effects subsequently.

MPTP treatment impairs tyrosine hydroxylase immunopositive fibers not only in the striatum, but also in the amygdala.

Parkinson's disease (PD) is characterized by a triad of symptoms (tremor, rigidity, and bradykinesia). Aside from this, emotional deficits are known to be associated with PD. A key structure of emotional processing is the amygdala. Emotional deficits seen in PD might be due to alterations in the catecholaminergic innervation of this limbic structure. We therefore examined whether 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) applied to C57/BL6 mice (an animal model of PD) affects the density of tyrosine hydroxylase (TH) immunoreactive fibers in the amygdala as it does in the striatum. MPTP treatment caused a prominent reduction in dopamine levels (about -70%) in the striatum (determined by high-performance liquid chromatography and electrochemical detection), accompanied by massive losses of TH-positive fibers in the striatum (-48.3%). Moreover, MPTP treatment caused prominent reductions of TH-positive fiber densities in the basolateral, lateral and central nucleus of the amygdala (about -20%). These results may provide the morphological basis for behavioral studies analyzing altered emotional responses in animal models of PD.

Analyzing the traumatic impact of childhood visual impairment.

Material is presented from three analyses involving the impact on adult functioning of childhood trauma to the visual system. The clinical process by which unrecognized but ongoing traumatic reactions are identified for subsequent analysis is described. It is of particular importance, with these patients, to recognize their lifelong experience of visual confusion resulting from problems in their visual anatomy. Only then can fantasies and affects related to these physically induced states of confusion be worked through. Working through these reactions promotes the neutralization of related primitive narcissistic affects, mourning, and realistic accommodation, and leads to a more intact and integrated sense of self, and a marked increase in self-esteem. With this newly integrated sense of self, the complex interaction between physically induced confusion states and more typical developmental conflicts with objects can be worked through, resulting in more realistic and intense cathexes of the external world. The trauma suffered by these patients had been greatly compounded by its having gone unrecognized. To miss this yet again in an analysis is to repeat the past and retraumatize the patient. These findings have clear implications for patients with other biologically related symptoms (e.g., ADD, ADHD, and dyslexia).