Behavioral Reaction and Expression after Opioids Injection into the Pedunculopontine Tegmental Nucleus and Electrical Stimulation of the Ventral Tegmental Area.

The pedunculopontine tegmental nucleus (PPN) regulates the activity of dopaminergic cells in the ventral tegmental area (VTA). In this study, the role of opioid receptors (OR) in the PPN on motivated behaviors was investigated by using a model of feeding induced by electrical VTA-stimulation (Es-VTA) in rats (male Wistar; n = 91). We found that the OR excitation by morphine and their blocking by naloxone within the PPN caused a change in the analyzed motivational behavior and neuronal activation.

Subthalamic Deep Brain Stimulation Affects Plasma Corticosterone Concentration and Peripheral Immunity Changes in Rat Model of Parkinson's Disease.

Deep brain stimulation of the subthalamic nucleus (DBS-STN) is an effective treatment for advanced motor symptoms of Parkinson's disease (PD). Recently, a connection between the limbic part of the STN and side effects of DBS-STN has been increasingly recognized. Animal studies have shown that DBS-STN influences behavior and provokes neurochemical changes in regions of the limbic system.

NMDA receptor modulation of the pedunculopontine tegmental nucleus underlies the motivational drive for feeding induced by midbrain dopaminergic neurons.

The mesolimbic system, particularly the somatodendritic ventral tegmental area (VTA), is responsible for the positive reinforcing aspects of various homeostatic stimuli. In turn, the pedunculopontine tegmental nucleus (PPN) is anatomically and functionally connected with the VTA and substantia nigra (SN). In the present study, we investigated the role of glutamate receptors in the PPN in motivated behaviors by using a model of feeding induced by electrical stimulation of the VTA in male Wistar rats (n = 80).

Dimethyl fumarate attenuates intracerebroventricular streptozotocin-induced spatial memory impairment and hippocampal neurodegeneration in rats.

Intracerebroventricular (ICV) injection of streptozotocin (STZ) is a widely-accepted animal model of sporadic Alzheimer's disease (sAD). The present study evaluated the ability of dimethyl fumarate (DMF), an agent with antioxidant and anti-inflammatory properties, to prevent spatial memory impairments and hippocampal neurodegeneration mediated by ICV injection of STZ in 4-month-old rats. Rodent chow containing DMF (0.

Effects of chronic desipramine pretreatment on open field-induced suppression of blood natural killer cell activity and cytokine response depend on the rat's behavioral characteristics.

Effects of 14 consecutive day exposure to desipramine (10mg/kg i.p.), by itself or following chronic open field (OF) exposure, on subsequent neuroimmunological effects of acute (30 min) OF stress and the involvement of individual differences in response to novelty or social position in the anti-depressive responsiveness were investigated.

Locomotor response to novelty correlates with differences in number and morphology of hypothalamic tyrosine hydroxylase positive cells in rats.

Individual differences in the intensity of locomotor response to a new environment (exploratory reaction) are generally used as a model to study individual vulnerability to stress and drug addiction. In the present work we studied the number, distribution and morphology of the hypothalamic cells expressing tyrosine hydroxylase (TH+ cells) (immunohistochemical and immunofluorescent staining) in male Wistar rats divided based on high (HR), midline (MR) or low (LR) locomotor activity in response to novelty. Morphology and total number of TH+ cells were analyzed for A11-A15 dopaminergic groups.

Chronic antidepressant desipramine treatment increases open field-induced brain expression and spleen production of interleukin 10 in rats.

In the present study, we established a role of individual differences in locomotor response to novelty or social position in modulatory effect of chronic (14 consecutive days) antidepressant drug desipramine pretreatment (10mg/kg i.p.) on acute (30 min), white and illuminated open field (OF)-induced changes in spleen anti-tumor activity of natural killer (NK) cells (chromium release assay) in parallel to the brain anti-inflammatory interleukin 10 (IL-10) and Fos expression (immunohistochemistry), splenocytic pro-inflammatory interferon γ (IFN-γ) and IL-10 production (ELISA), and plasma corticosterone concentration (RIA) in rats.

Behavioral response elicited by stimulation of the mesolimbic system after procaine and bicuculline injection into the pedunculopontine tegmental nucleus in rats.

The pedunculopontine tegmental nucleus (PPN) is anatomically connected with dopaminergic cells in the ventral tegmental area (VTA). In the present study, VTA-stimulation induced feeding or locomotor response was tested after temporary inactivation (procaine injection) or activation (bicuculline injection) of the PPN in the ipsi- or contralateral hemisphere. Motor and motivation aspects of appetitive behavior were analyzed on the basis of the latency/stimulation frequency curve shift paradigm, in male Wistar rats (n=48).

Stress-induced differences in the limbic system Fos expression are more pronounced in rats differing in responsiveness to novelty than social position.

We determined the interaction between such individual behavioural profiles as locomotor response to novelty or social position and the activation (Fos expression) of the brain's limbic regions following chronic laboratory and social interaction stress. Male Wistar rats (n=45), housed separately and handled for 2 weeks, were divided into high (HR) and low (LR) responders to novelty. Seven days later, 12 HRs and 12 LRs were subjected to a chronic 23 consecutive day social interaction test (Nov/SocI group), 5 HRs and 5 LRs were subjected to chronic laboratory stress: carrying from the vivarium to the laboratory for 23 consecutive days (Nov/Carr group) while the remaining rats stayed in the vivarium in their home cages (Nov/Home group).

Blood natural killer cell cytotoxicity enhancement correlates with an increased activity in brain motor structures following chronic stimulation of the bed nucleus of the stria terminalis in rats.

The present study indicates that a chronic 14 day electrical stimulation of the bed nucleus of the stria terminalis (BST) increased blood but not spleen natural killer cell (NK) cytotoxicity and a large granular lymphocyte (LGL) number. These immune changes positively correlated with the increased activity in brain cortical and subcortical motor structures that influence the BST stimulation-induced behavioral response. No significant changes in blood and spleen leukocyte population numbers and plasma corticosterone concentration after the stimulation were found.

Locomotor response to novelty correlates with the number of midbrain tyrosine hydroxylase positive cells in rats.

The present study investigated whether the higher dopaminergic system activation in rats with high (HRs) rather than low (LRs) locomotor activity in response to novelty depend on the number of cells containing the enzyme tyrosine hydroxylase (TH(+)) and/or differences in the morphology of these cells. One week after the novelty test, brains from male Wistar rats (HRs and LRs) were collected and stained for TH expression (immunohistochemistry) and for morphological analysis (immunofluorescent staining). The morphology and total number of TH(+) cells was analyzed for each A9 (substantia nigra) and A10 (ventral tegmental area) group of the midbrain dopaminergic cells.

Lesion of the ventral tegmental area amplifies stimulation-induced Fos expression in the rat brain.

Unilateral lesions of the ventral tegmental area (VTA), the key structure of the mesolimbic system, facilitate behavioral responses induced by electrical stimulation of the VTA in the contralateral hemisphere. In search of the neuronal mechanism behind this phenomenon, Fos expression was used to measure neuronal activation of the target mesolimbic structures in rats subjected to unilateral electrocoagulation and simultaneously to contralateral electrical stimulation of the VTA (L/S group). These were compared to the level of mesolimbic activation after unilateral electrocoagulation of the VTA (L group), unilateral electrical stimulation of the VTA (S group) and bilateral electrode implantation into the VTA in the sham (Sh) group.