An fMRI Study of Adult Brain Cortical Activation Following Intensive Learning.

Functional imaging techniques, fMRI in particular, has given the possibility to investigate non-invasively the cognitive processes in healthy populations and different disorders concerning neuro-psychiatry, thus unfolding the concepts guiding diagnosis and patient management. Different brain structures seem to support different types of cognitive functions in particular learning and memory thus the neurobiological explanation of the retrieval of information is associated with knowledge of brain plasticity, memory circuits, synaptic neurotransmission and the modulation of glial cells. Consistent with fMRI investigations of memory systems we tested the dependability of a memory paradigm using heterogeneous memory stimuli in order to find the neurobiological basis that correlates with memory task performance. Our study resulted with statistical significant differences in brain activations across the block design contrasts in both occipital and temporal regions in 29 mentally healthy students during a memory paradigm performance after intensive learning. As functional magnetic resonance imaging has become an important and reliable tool for investigation of brain anatomy and its function in health and disease, it becomes clear that further research of neurobiological basis of cognitive and memory domains can clarify different diagnostic prototypes and thus explain the human brain impairments in neuropsychological patients, since these are characterized by various cognitive dysfunctions.

Effects of new generation triptans - frovatriptan and almotriptan - on hemodynamic parameters in intact male and female rats.

The introduction of the second generation triptans in clinical and experimental practice was a major progress in the pharmacotherapy of migraine. Frovatriptan is a second generation triptan with strong 5-HT1B/1D serotonergic agonism and low 5-HT1A/7 receptor affinity, while almotriptan possesses not only the typical 5-HT1B/1D receptor agonist activity, but shows an affinity to the 5-HT1F receptor. The aim of our study was to assess the impact of frovatriptan and almotriptan on hemodynamics in male and female rats. We used a non-invasive "tail-cuff" method to measure the arterial blood pressure. Female and male Wistar rats were treated separately with high and low dosages of frovatriptan and almotriptan. Male and female rats showed reduction in all hemodynamic parameters, but only male rats showed an increase in the heart rate. In general, we could say that both almotriptan and frovatriptan potentiate cardiovascular safety.

Aronia melanocarpa (Michx.) Elliot fruit juice reveals neuroprotective effect and improves cognitive and locomotor functions of aged rats.

The aim of the study was to investigate the effect of polyphenol-rich Aronia melanocarpa (Michx.) Elliot juice (AMJ) on learning ability and memory, and brain morphology of aged rats. A model of healthy male Wistar rats (24 months of age) divided in 2 groups was used: AMJ group supplemented orally with AMJ (10 mL/kg for 105 days) and old control (CO) group without supplementation. Activity cage test showed that AMJ supplemented rats increased the number of vertical movements compared with old controls (p < 0.05). In active avoidance test, supplemented rats increased the number of avoidances on 3rd, 4th and 5th days of learning session, compared with the respective day of old controls (p < 0.05). AMJ supplementation did not affect the mean neuronal number in the dentate gyrus but significantly increased the density of nerve fibers in the perforant path of the hippocampus (p < 0.05). AMJ supplementation increased acetylcholinesterase activity in hippocampus, which is a marker of improved functional activity of the cholinergic neurons. These results indicate that AMJ induced ameliorating changes in the ability of old rats to learn tasks and improved their locomotor functions. AMJ showed a neuroprotective effect by increasing the density of nerve fibers in the hippocampal perforant pathway.

Effects of acute hypoxic provocation on the autonomic nervous system in 'healthy' young smokers, measured by heart rate variability.

AIM: The aim of this study was to compare the activity of the autonomic nervous system (ANS) using heart rate variability (HRV) in 'healthy' young smokers and non-smokers before, during and after exogenous hypoxic provocation. METHODS: Twenty-one healthy non-smoking males aged 28.0 ± 7.4 years (mean ± SD) and 14 'healthy' smoking males aged 28.1 ± 4.3 years with 9.2 ± 5.6 pack-years were subjected to one-hour hypoxic exposure (FiO2 = 12.3 ± 1.5%) via a hypoxicator. HRV data was derived via Kubios HRV, Finland software by analysing the pre-hypoxic, hypoxic and post-hypoxic periods. RESULTS: Standard deviation of the intervals between normal beats (SDNN) was higher in the non-smokers in the pre-hypoxic period (62.0 ± 32.1 vs 40.3 ± 16.2 ms, p = 0.013) but not in the hypoxic period (75.7 ± 34.8 vs 57.9 ± 18.3 ms, p = 0.167). When comparing intra-group HRV changes, shifting from hypoxic to normoxic conditions, there was an increase in the mean square root of successive R-R interval differences (RMSSD) (65.9 ± 40.2 vs 75.1 ± 45.9 ms, p = 0.011), but these changes were observed in only the group of non-smokers. CONCLUSIONS: Smoking probably impairs autonomic regulation in healthy young males and may lead to decreased HRV, even before subjective clinical signs and symptoms appear.

A Review of Neuroimaging Studies on Working Memory Paradigms in Patients with Bipolar Disorder.

New brain technologies including neuroimaging studies are powerful means for providing new insights into clinical and cognitive neuroscience. Bipolar disorder is a severe chronic phasic mental disease characterized by various cognitive dysfunctions. Working memory is one prominent domain of cognitive impairment in bipolar disorder. Disruptions in working memory are observed even in euthymic bipolar patients which makes it a potential endophenotypic marker for the disorder. Finding such markers may help in providing firm neurobiological basis for psychiatric nosologies and symptomatic presentations. This review aims to summarize some of the important aspects of findings from functional magnetic resonance imaging studies on the activation of brain structures in relation to working memory paradigms.

Cognitive Impairment in Schizophrenia, Neurotransmitters and the New Atypical Antipsychotic Aripiprazole.

Cognition is a group of mental processes that includes the capacity to perceive, think, learn and to study, and the capacity of the brain to analyze information and program adaptive behaviour. Although there has been an appreciable evolution in the therapy of psychoses in the last twenty-five years, cognitive disturbances still persist in spite of antipsychotic treatment. The cognitive decay disrupts the ability of clinically diagnosed patients with psychoses, mainly schizophrenia, to learn and to memorize skills that are useful for their family and social relationships. Moreover, cognitive deficiency is often considered to be crucial for further rehabilitation. In atypical antipsychotics there are big differences in the effects on cognitive functions. Some clinical studies demonstrate the benefits of a third generation of antipsychotics on cognitive functions in patients treated for mental illnesses. In the present study we have reviewed many articles investigating the influence of aripiprazole on cognition in human and animal subjects. Aripiprazole is a third generation antipsychotic drug that possesses a unique pharmacodynamic profile, which in conjunction with recently published scientific data on the drugs' influence on antidepressant, anxiolytic and cognitive functions, suggests a highly positive future potential for restorative cognitive treatment and ongoing healthy function. The data included in the review will contribute to determining the potential benefits of aripiprazole on memory and training processes.